Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Theory: Explanation and Fundamentalism
Ioan Muntean
Department of PhilosophyPurdue University–Indiana University, Fort Wayne
Philosophy of Science Association Meeting, Montreal,November 2010
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Two pathways towards Quantum Gravity (QG)
1 Find answers (new or right) to perennial philosophicalproblems in QG (“Philosophical centrism”)
2 Analyze QG as scientific theories or, better, programs(“Philosophical analysis”)
1 ambitious and reformist (integrated in a form of scientism).Useful for metaphysics
2 useful in philosophy of science/physics. Can be normative. . .
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Two pathways towards Quantum Gravity (QG)
1 Find answers (new or right) to perennial philosophicalproblems in QG (“Philosophical centrism”)
2 Analyze QG as scientific theories or, better, programs(“Philosophical analysis”)
1 ambitious and reformist (integrated in a form of scientism).Useful for metaphysics
2 useful in philosophy of science/physics. Can be normative. . .
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Two pathways towards Quantum Gravity (QG)
1 Find answers (new or right) to perennial philosophicalproblems in QG (“Philosophical centrism”)
2 Analyze QG as scientific theories or, better, programs(“Philosophical analysis”)
1 ambitious and reformist (integrated in a form of scientism).Useful for metaphysics
2 useful in philosophy of science/physics. Can be normative. . .
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Two pathways towards Quantum Gravity (QG)
1 Find answers (new or right) to perennial philosophicalproblems in QG (“Philosophical centrism”)
2 Analyze QG as scientific theories or, better, programs(“Philosophical analysis”)
1 ambitious and reformist (integrated in a form of scientism).Useful for metaphysics
2 useful in philosophy of science/physics. Can be normative. . .
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Two pathways towards Quantum Gravity (QG)
1 Find answers (new or right) to perennial philosophicalproblems in QG (“Philosophical centrism”)
2 Analyze QG as scientific theories or, better, programs(“Philosophical analysis”)
1 ambitious and reformist (integrated in a form of scientism).Useful for metaphysics
2 useful in philosophy of science/physics. Can be normative. . .
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
1 Philosophical centrism
Most QG programs say something special about our oldmetaphysical concepts:
the nature of spacetime, space or timethe measurement problemthe ultimate nature of objects/processes/events in the world
Question Q1
Which Quantum Gravity program provides the best answer to themetaphysical question X?
In most cases, QG are prescriptive in respect of time, space,quantization etc.
???????
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
1 Philosophical centrism
Most QG programs say something special about our oldmetaphysical concepts:
the nature of spacetime, space or timethe measurement problemthe ultimate nature of objects/processes/events in the world
Question Q1
Which Quantum Gravity program provides the best answer to themetaphysical question X?
In most cases, QG are prescriptive in respect of time, space,quantization etc.
???????
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
1 Philosophical centrism
Most QG programs say something special about our oldmetaphysical concepts:
the nature of spacetime, space or time
the measurement problemthe ultimate nature of objects/processes/events in the world
Question Q1
Which Quantum Gravity program provides the best answer to themetaphysical question X?
In most cases, QG are prescriptive in respect of time, space,quantization etc.
???????
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
1 Philosophical centrism
Most QG programs say something special about our oldmetaphysical concepts:
the nature of spacetime, space or timethe measurement problem
the ultimate nature of objects/processes/events in the world
Question Q1
Which Quantum Gravity program provides the best answer to themetaphysical question X?
In most cases, QG are prescriptive in respect of time, space,quantization etc.
???????
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
1 Philosophical centrism
Most QG programs say something special about our oldmetaphysical concepts:
the nature of spacetime, space or timethe measurement problemthe ultimate nature of objects/processes/events in the world
Question Q1
Which Quantum Gravity program provides the best answer to themetaphysical question X?
In most cases, QG are prescriptive in respect of time, space,quantization etc.
???????
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
1 Philosophical centrism
Most QG programs say something special about our oldmetaphysical concepts:
the nature of spacetime, space or timethe measurement problemthe ultimate nature of objects/processes/events in the world
Question Q1
Which Quantum Gravity program provides the best answer to themetaphysical question X?
In most cases, QG are prescriptive in respect of time, space,quantization etc.
???????
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
1 Philosophical centrism
Most QG programs say something special about our oldmetaphysical concepts:
the nature of spacetime, space or timethe measurement problemthe ultimate nature of objects/processes/events in the world
Question Q1
Which Quantum Gravity program provides the best answer to themetaphysical question X?
In most cases, QG are prescriptive in respect of time, space,quantization etc.
???????
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
1 Philosophical centrism
Most QG programs say something special about our oldmetaphysical concepts:
the nature of spacetime, space or timethe measurement problemthe ultimate nature of objects/processes/events in the world
Question Q1
Which Quantum Gravity program provides the best answer to themetaphysical question X?
In most cases, QG are prescriptive in respect of time, space,quantization etc.
???????
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
1 Philosophical centrism
Most QG programs say something special about our oldmetaphysical concepts:
the nature of spacetime, space or timethe measurement problemthe ultimate nature of objects/processes/events in the world
Question Q1
Which Quantum Gravity program provides the best answer to themetaphysical question X?
In most cases, QG are prescriptive in respect of time, space,quantization etc.
???????
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Philosophers should be doing this!
Sometimes philosophers help with insights in the problem ofspace, time, change, dynamics, etc.
“General relativity and quantum field theory are based onsome profound insights about the nature of reality. Theseinsights are crystallized in the form of mathematics, butthere is a limit to how much progress we can make byjust playing around with this mathematics. We need togo back to the insights behind general relativity andquantum field theory, learn to hold them together in ourminds, and dare to imagine a world more strange, morebeautiful, but ultimately more reasonable than ourcurrent theories of it. For this daunting task,philosophical reflection is bound to be of help.” (J. Baezin ?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Philosophers should be doing this!
Sometimes philosophers help with insights in the problem ofspace, time, change, dynamics, etc.
“General relativity and quantum field theory are based onsome profound insights about the nature of reality. Theseinsights are crystallized in the form of mathematics, butthere is a limit to how much progress we can make byjust playing around with this mathematics. We need togo back to the insights behind general relativity andquantum field theory, learn to hold them together in ourminds, and dare to imagine a world more strange, morebeautiful, but ultimately more reasonable than ourcurrent theories of it. For this daunting task,philosophical reflection is bound to be of help.” (J. Baezin ?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Philosophers should be doing this!
Sometimes philosophers help with insights in the problem ofspace, time, change, dynamics, etc.
“General relativity and quantum field theory are based onsome profound insights about the nature of reality. Theseinsights are crystallized in the form of mathematics, butthere is a limit to how much progress we can make byjust playing around with this mathematics. We need togo back to the insights behind general relativity andquantum field theory, learn to hold them together in ourminds, and dare to imagine a world more strange, morebeautiful, but ultimately more reasonable than ourcurrent theories of it. For this daunting task,philosophical reflection is bound to be of help.” (J. Baezin ?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
1’. Yet another philosophical centrism
Strengthen an existing metaphysics by interpreting QG
Structural Realism and QGIdentity and individuation of objects and QG (compare andcontrast with QM and QFT)Part-whole relations and QG.
For Structural Realism and QG see ?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
1’. Yet another philosophical centrism
Strengthen an existing metaphysics by interpreting QG
Structural Realism and QG
Identity and individuation of objects and QG (compare andcontrast with QM and QFT)Part-whole relations and QG.
For Structural Realism and QG see ?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
1’. Yet another philosophical centrism
Strengthen an existing metaphysics by interpreting QG
Structural Realism and QGIdentity and individuation of objects and QG (compare andcontrast with QM and QFT)
Part-whole relations and QG.
For Structural Realism and QG see ?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
1’. Yet another philosophical centrism
Strengthen an existing metaphysics by interpreting QG
Structural Realism and QGIdentity and individuation of objects and QG (compare andcontrast with QM and QFT)Part-whole relations and QG.
For Structural Realism and QG see ?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
1’. Yet another philosophical centrism
Strengthen an existing metaphysics by interpreting QG
Structural Realism and QGIdentity and individuation of objects and QG (compare andcontrast with QM and QFT)Part-whole relations and QG.
For Structural Realism and QG see ?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
2. Philosophical pathways to QG
Which QG program is the best as a scientific endeavor?
Question Q2
Which QG program is the best in respect of a given virtue V?
Question Q2’
Which Quantum Gravity program has the drawback D?
This is discussed by fewer philosophers ???
I plan to follow something similar here
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
2. Philosophical pathways to QG
Which QG program is the best as a scientific endeavor?
Question Q2
Which QG program is the best in respect of a given virtue V?
Question Q2’
Which Quantum Gravity program has the drawback D?
This is discussed by fewer philosophers ???
I plan to follow something similar here
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
2. Philosophical pathways to QG
Which QG program is the best as a scientific endeavor?
Question Q2
Which QG program is the best in respect of a given virtue V?
Question Q2’
Which Quantum Gravity program has the drawback D?
This is discussed by fewer philosophers ???
I plan to follow something similar here
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
2. Philosophical pathways to QG
Which QG program is the best as a scientific endeavor?
Question Q2
Which QG program is the best in respect of a given virtue V?
Question Q2’
Which Quantum Gravity program has the drawback D?
This is discussed by fewer philosophers ???
I plan to follow something similar here
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
2. Philosophical pathways to QG
Which QG program is the best as a scientific endeavor?
Question Q2
Which QG program is the best in respect of a given virtue V?
Question Q2’
Which Quantum Gravity program has the drawback D?
This is discussed by fewer philosophers ???
I plan to follow something similar here
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
2. Philosophical pathways to QG
Which QG program is the best as a scientific endeavor?
Question Q2
Which QG program is the best in respect of a given virtue V?
Question Q2’
Which Quantum Gravity program has the drawback D?
This is discussed by fewer philosophers ???
I plan to follow something similar here
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
2. Philosophical pathways to QG
Which QG program is the best as a scientific endeavor?
Question Q2
Which QG program is the best in respect of a given virtue V?
Question Q2’
Which Quantum Gravity program has the drawback D?
This is discussed by fewer philosophers ???
I plan to follow something similar here
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
A narrow scope
I give up the comparative aspects of Q2 and Q2’and focus onone QG program
Question
Is string theory a successful QG program?
Dimensions of success of theories:
1 Empirical confirmation (preferably direct)2 Predictive success (preferably novel)3 Non-empirical virtues: unification, explanation, elegance,
simplicity4 Problem solving (preferably real problems), etc.5 Fecundity6 Meshing well with other scientific theories
None of them is necessary and sufficient.Are these applicable to String Theory or QG in general?ST does not score well on this scoreboard
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
A narrow scope
I give up the comparative aspects of Q2 and Q2’and focus onone QG program
Question
Is string theory a successful QG program?
Dimensions of success of theories:
1 Empirical confirmation (preferably direct)2 Predictive success (preferably novel)3 Non-empirical virtues: unification, explanation, elegance,
simplicity4 Problem solving (preferably real problems), etc.5 Fecundity6 Meshing well with other scientific theories
None of them is necessary and sufficient.Are these applicable to String Theory or QG in general?ST does not score well on this scoreboard
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
A narrow scope
I give up the comparative aspects of Q2 and Q2’and focus onone QG program
Question
Is string theory a successful QG program?
Dimensions of success of theories:
1 Empirical confirmation (preferably direct)2 Predictive success (preferably novel)3 Non-empirical virtues: unification, explanation, elegance,
simplicity4 Problem solving (preferably real problems), etc.5 Fecundity6 Meshing well with other scientific theories
None of them is necessary and sufficient.Are these applicable to String Theory or QG in general?ST does not score well on this scoreboard
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
A narrow scope
I give up the comparative aspects of Q2 and Q2’and focus onone QG program
Question
Is string theory a successful QG program?
Dimensions of success of theories:
1 Empirical confirmation (preferably direct)2 Predictive success (preferably novel)3 Non-empirical virtues: unification, explanation, elegance,
simplicity4 Problem solving (preferably real problems), etc.5 Fecundity6 Meshing well with other scientific theories
None of them is necessary and sufficient.Are these applicable to String Theory or QG in general?ST does not score well on this scoreboard
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
A narrow scope
I give up the comparative aspects of Q2 and Q2’and focus onone QG program
Question
Is string theory a successful QG program?
Dimensions of success of theories:1 Empirical confirmation (preferably direct)
2 Predictive success (preferably novel)3 Non-empirical virtues: unification, explanation, elegance,
simplicity4 Problem solving (preferably real problems), etc.5 Fecundity6 Meshing well with other scientific theories
None of them is necessary and sufficient.Are these applicable to String Theory or QG in general?ST does not score well on this scoreboard
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
A narrow scope
I give up the comparative aspects of Q2 and Q2’and focus onone QG program
Question
Is string theory a successful QG program?
Dimensions of success of theories:1 Empirical confirmation (preferably direct)2 Predictive success (preferably novel)
3 Non-empirical virtues: unification, explanation, elegance,simplicity
4 Problem solving (preferably real problems), etc.5 Fecundity6 Meshing well with other scientific theories
None of them is necessary and sufficient.Are these applicable to String Theory or QG in general?ST does not score well on this scoreboard
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
A narrow scope
I give up the comparative aspects of Q2 and Q2’and focus onone QG program
Question
Is string theory a successful QG program?
Dimensions of success of theories:1 Empirical confirmation (preferably direct)2 Predictive success (preferably novel)3 Non-empirical virtues: unification, explanation, elegance,
simplicity
4 Problem solving (preferably real problems), etc.5 Fecundity6 Meshing well with other scientific theories
None of them is necessary and sufficient.Are these applicable to String Theory or QG in general?ST does not score well on this scoreboard
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
A narrow scope
I give up the comparative aspects of Q2 and Q2’and focus onone QG program
Question
Is string theory a successful QG program?
Dimensions of success of theories:1 Empirical confirmation (preferably direct)2 Predictive success (preferably novel)3 Non-empirical virtues: unification, explanation, elegance,
simplicity4 Problem solving (preferably real problems), etc.
5 Fecundity6 Meshing well with other scientific theories
None of them is necessary and sufficient.Are these applicable to String Theory or QG in general?ST does not score well on this scoreboard
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
A narrow scope
I give up the comparative aspects of Q2 and Q2’and focus onone QG program
Question
Is string theory a successful QG program?
Dimensions of success of theories:1 Empirical confirmation (preferably direct)2 Predictive success (preferably novel)3 Non-empirical virtues: unification, explanation, elegance,
simplicity4 Problem solving (preferably real problems), etc.5 Fecundity
6 Meshing well with other scientific theories
None of them is necessary and sufficient.Are these applicable to String Theory or QG in general?ST does not score well on this scoreboard
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
A narrow scope
I give up the comparative aspects of Q2 and Q2’and focus onone QG program
Question
Is string theory a successful QG program?
Dimensions of success of theories:1 Empirical confirmation (preferably direct)2 Predictive success (preferably novel)3 Non-empirical virtues: unification, explanation, elegance,
simplicity4 Problem solving (preferably real problems), etc.5 Fecundity6 Meshing well with other scientific theories
None of them is necessary and sufficient.Are these applicable to String Theory or QG in general?ST does not score well on this scoreboard
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
A narrow scope
I give up the comparative aspects of Q2 and Q2’and focus onone QG program
Question
Is string theory a successful QG program?
Dimensions of success of theories:1 Empirical confirmation (preferably direct)2 Predictive success (preferably novel)3 Non-empirical virtues: unification, explanation, elegance,
simplicity4 Problem solving (preferably real problems), etc.5 Fecundity6 Meshing well with other scientific theories
None of them is necessary and sufficient.
Are these applicable to String Theory or QG in general?ST does not score well on this scoreboard
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
A narrow scope
I give up the comparative aspects of Q2 and Q2’and focus onone QG program
Question
Is string theory a successful QG program?
Dimensions of success of theories:1 Empirical confirmation (preferably direct)2 Predictive success (preferably novel)3 Non-empirical virtues: unification, explanation, elegance,
simplicity4 Problem solving (preferably real problems), etc.5 Fecundity6 Meshing well with other scientific theories
None of them is necessary and sufficient.Are these applicable to String Theory or QG in general?
ST does not score well on this scoreboard
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
A narrow scope
I give up the comparative aspects of Q2 and Q2’and focus onone QG program
Question
Is string theory a successful QG program?
Dimensions of success of theories:1 Empirical confirmation (preferably direct)2 Predictive success (preferably novel)3 Non-empirical virtues: unification, explanation, elegance,
simplicity4 Problem solving (preferably real problems), etc.5 Fecundity6 Meshing well with other scientific theories
None of them is necessary and sufficient.Are these applicable to String Theory or QG in general?ST does not score well on this scoreboard
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Some reasons to . . . love string theory
It solves some problems:
the ultraviolet divergences of General Relativity and ofStandard Model.no dimensionless free parameters.
Is the dominant research program in quantum gravity (QG)Is the (leading?) contender for a theory of everything:
Advertised as: “a single theory that, in principle is capable ofdescribing all phenomena” ((?, ix)).Heavily advertised in popularizing literature, perhaps the bestknown quantum gravity program
Could tell us new stories about the world:
can talk evolution of the universe before the Big Bang(interpreted as a collision of branes)explains facts about black holes, dark matter etc.
But these are promises and prospective undertakings
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Some reasons to . . . love string theory
It solves some problems:
the ultraviolet divergences of General Relativity and ofStandard Model.no dimensionless free parameters.
Is the dominant research program in quantum gravity (QG)Is the (leading?) contender for a theory of everything:
Advertised as: “a single theory that, in principle is capable ofdescribing all phenomena” ((?, ix)).Heavily advertised in popularizing literature, perhaps the bestknown quantum gravity program
Could tell us new stories about the world:
can talk evolution of the universe before the Big Bang(interpreted as a collision of branes)explains facts about black holes, dark matter etc.
But these are promises and prospective undertakings
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Some reasons to . . . love string theory
It solves some problems:the ultraviolet divergences of General Relativity and ofStandard Model.
no dimensionless free parameters.
Is the dominant research program in quantum gravity (QG)Is the (leading?) contender for a theory of everything:
Advertised as: “a single theory that, in principle is capable ofdescribing all phenomena” ((?, ix)).Heavily advertised in popularizing literature, perhaps the bestknown quantum gravity program
Could tell us new stories about the world:
can talk evolution of the universe before the Big Bang(interpreted as a collision of branes)explains facts about black holes, dark matter etc.
But these are promises and prospective undertakings
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Some reasons to . . . love string theory
It solves some problems:the ultraviolet divergences of General Relativity and ofStandard Model.no dimensionless free parameters.
Is the dominant research program in quantum gravity (QG)Is the (leading?) contender for a theory of everything:
Advertised as: “a single theory that, in principle is capable ofdescribing all phenomena” ((?, ix)).Heavily advertised in popularizing literature, perhaps the bestknown quantum gravity program
Could tell us new stories about the world:
can talk evolution of the universe before the Big Bang(interpreted as a collision of branes)explains facts about black holes, dark matter etc.
But these are promises and prospective undertakings
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Some reasons to . . . love string theory
It solves some problems:the ultraviolet divergences of General Relativity and ofStandard Model.no dimensionless free parameters.
Is the dominant research program in quantum gravity (QG)
Is the (leading?) contender for a theory of everything:
Advertised as: “a single theory that, in principle is capable ofdescribing all phenomena” ((?, ix)).Heavily advertised in popularizing literature, perhaps the bestknown quantum gravity program
Could tell us new stories about the world:
can talk evolution of the universe before the Big Bang(interpreted as a collision of branes)explains facts about black holes, dark matter etc.
But these are promises and prospective undertakings
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Some reasons to . . . love string theory
It solves some problems:the ultraviolet divergences of General Relativity and ofStandard Model.no dimensionless free parameters.
Is the dominant research program in quantum gravity (QG)Is the (leading?) contender for a theory of everything:
Advertised as: “a single theory that, in principle is capable ofdescribing all phenomena” ((?, ix)).Heavily advertised in popularizing literature, perhaps the bestknown quantum gravity program
Could tell us new stories about the world:
can talk evolution of the universe before the Big Bang(interpreted as a collision of branes)explains facts about black holes, dark matter etc.
But these are promises and prospective undertakings
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Some reasons to . . . love string theory
It solves some problems:the ultraviolet divergences of General Relativity and ofStandard Model.no dimensionless free parameters.
Is the dominant research program in quantum gravity (QG)Is the (leading?) contender for a theory of everything:
Advertised as: “a single theory that, in principle is capable ofdescribing all phenomena” ((?, ix)).
Heavily advertised in popularizing literature, perhaps the bestknown quantum gravity program
Could tell us new stories about the world:
can talk evolution of the universe before the Big Bang(interpreted as a collision of branes)explains facts about black holes, dark matter etc.
But these are promises and prospective undertakings
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Some reasons to . . . love string theory
It solves some problems:the ultraviolet divergences of General Relativity and ofStandard Model.no dimensionless free parameters.
Is the dominant research program in quantum gravity (QG)Is the (leading?) contender for a theory of everything:
Advertised as: “a single theory that, in principle is capable ofdescribing all phenomena” ((?, ix)).Heavily advertised in popularizing literature, perhaps the bestknown quantum gravity program
Could tell us new stories about the world:
can talk evolution of the universe before the Big Bang(interpreted as a collision of branes)explains facts about black holes, dark matter etc.
But these are promises and prospective undertakings
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Some reasons to . . . love string theory
It solves some problems:the ultraviolet divergences of General Relativity and ofStandard Model.no dimensionless free parameters.
Is the dominant research program in quantum gravity (QG)Is the (leading?) contender for a theory of everything:
Advertised as: “a single theory that, in principle is capable ofdescribing all phenomena” ((?, ix)).Heavily advertised in popularizing literature, perhaps the bestknown quantum gravity program
Could tell us new stories about the world:
can talk evolution of the universe before the Big Bang(interpreted as a collision of branes)explains facts about black holes, dark matter etc.
But these are promises and prospective undertakings
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Some reasons to . . . love string theory
It solves some problems:the ultraviolet divergences of General Relativity and ofStandard Model.no dimensionless free parameters.
Is the dominant research program in quantum gravity (QG)Is the (leading?) contender for a theory of everything:
Advertised as: “a single theory that, in principle is capable ofdescribing all phenomena” ((?, ix)).Heavily advertised in popularizing literature, perhaps the bestknown quantum gravity program
Could tell us new stories about the world:can talk evolution of the universe before the Big Bang(interpreted as a collision of branes)
explains facts about black holes, dark matter etc.
But these are promises and prospective undertakings
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Some reasons to . . . love string theory
It solves some problems:the ultraviolet divergences of General Relativity and ofStandard Model.no dimensionless free parameters.
Is the dominant research program in quantum gravity (QG)Is the (leading?) contender for a theory of everything:
Advertised as: “a single theory that, in principle is capable ofdescribing all phenomena” ((?, ix)).Heavily advertised in popularizing literature, perhaps the bestknown quantum gravity program
Could tell us new stories about the world:can talk evolution of the universe before the Big Bang(interpreted as a collision of branes)explains facts about black holes, dark matter etc.
But these are promises and prospective undertakings
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Some reasons to . . . love string theory
It solves some problems:the ultraviolet divergences of General Relativity and ofStandard Model.no dimensionless free parameters.
Is the dominant research program in quantum gravity (QG)Is the (leading?) contender for a theory of everything:
Advertised as: “a single theory that, in principle is capable ofdescribing all phenomena” ((?, ix)).Heavily advertised in popularizing literature, perhaps the bestknown quantum gravity program
Could tell us new stories about the world:can talk evolution of the universe before the Big Bang(interpreted as a collision of branes)explains facts about black holes, dark matter etc.
But these are promises and prospective undertakingsIoan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
More reasons to. . . love ST
It is “science in the making”
It is mathematically fertile and can provide “mathematicalpredictions” (?)
It is open to interpretive questions (?)
As any other QG, it is a fertile middle ground betweenphilosophy (metaphysics and epistemology) and theoreticalphysics
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
More reasons to. . . love ST
It is “science in the making”
It is mathematically fertile and can provide “mathematicalpredictions” (?)
It is open to interpretive questions (?)
As any other QG, it is a fertile middle ground betweenphilosophy (metaphysics and epistemology) and theoreticalphysics
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
More reasons to. . . love ST
It is “science in the making”
It is mathematically fertile and can provide “mathematicalpredictions” (?)
It is open to interpretive questions (?)
As any other QG, it is a fertile middle ground betweenphilosophy (metaphysics and epistemology) and theoreticalphysics
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
More reasons to. . . love ST
It is “science in the making”
It is mathematically fertile and can provide “mathematicalpredictions” (?)
It is open to interpretive questions (?)
As any other QG, it is a fertile middle ground betweenphilosophy (metaphysics and epistemology) and theoreticalphysics
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
More reasons to. . . love ST
It is “science in the making”
It is mathematically fertile and can provide “mathematicalpredictions” (?)
It is open to interpretive questions (?)
As any other QG, it is a fertile middle ground betweenphilosophy (metaphysics and epistemology) and theoreticalphysics
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Amendments
String theory does not have the features of a scientific theory
Call it a program/direction of research, not a theory
Interpret it as a collection of mathematical models
1 each model is false and has intentional falsities inserted2 the model does not latch onto the world
string theory does not explains facts, at least not directly.
it may predict mathematical facts or even providemathematical results
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Amendments
String theory does not have the features of a scientific theory
Call it a program/direction of research, not a theory
Interpret it as a collection of mathematical models
1 each model is false and has intentional falsities inserted2 the model does not latch onto the world
string theory does not explains facts, at least not directly.
it may predict mathematical facts or even providemathematical results
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Amendments
String theory does not have the features of a scientific theory
Call it a program/direction of research, not a theory
Interpret it as a collection of mathematical models
1 each model is false and has intentional falsities inserted2 the model does not latch onto the world
string theory does not explains facts, at least not directly.
it may predict mathematical facts or even providemathematical results
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Amendments
String theory does not have the features of a scientific theory
Call it a program/direction of research, not a theory
Interpret it as a collection of mathematical models
1 each model is false and has intentional falsities inserted2 the model does not latch onto the world
string theory does not explains facts, at least not directly.
it may predict mathematical facts or even providemathematical results
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Amendments
String theory does not have the features of a scientific theory
Call it a program/direction of research, not a theory
Interpret it as a collection of mathematical models1 each model is false and has intentional falsities inserted
2 the model does not latch onto the world
string theory does not explains facts, at least not directly.
it may predict mathematical facts or even providemathematical results
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Amendments
String theory does not have the features of a scientific theory
Call it a program/direction of research, not a theory
Interpret it as a collection of mathematical models1 each model is false and has intentional falsities inserted2 the model does not latch onto the world
string theory does not explains facts, at least not directly.
it may predict mathematical facts or even providemathematical results
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Amendments
String theory does not have the features of a scientific theory
Call it a program/direction of research, not a theory
Interpret it as a collection of mathematical models1 each model is false and has intentional falsities inserted2 the model does not latch onto the world
string theory does not explains facts, at least not directly.
it may predict mathematical facts or even providemathematical results
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Amendments
String theory does not have the features of a scientific theory
Call it a program/direction of research, not a theory
Interpret it as a collection of mathematical models1 each model is false and has intentional falsities inserted2 the model does not latch onto the world
string theory does not explains facts, at least not directly.
it may predict mathematical facts or even providemathematical results
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Some reasons not to. . . love it
String theory is a “glorified” QFT (and nothing more)
“a chip of the same block” as QFT has its own skeleton in thecloset
String theory:
is background dependent (Smolin, Rovelli, Penrose)does not seem to address deep philosophical issues (?)never solved or addressed the measurement problem
All known string theories are perturbation theories
String solutions are unstable (?)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Some reasons not to. . . love it
String theory is a “glorified” QFT (and nothing more)
“a chip of the same block” as QFT has its own skeleton in thecloset
String theory:
is background dependent (Smolin, Rovelli, Penrose)does not seem to address deep philosophical issues (?)never solved or addressed the measurement problem
All known string theories are perturbation theories
String solutions are unstable (?)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Some reasons not to. . . love it
String theory is a “glorified” QFT (and nothing more)
“a chip of the same block” as QFT has its own skeleton in thecloset
String theory:
is background dependent (Smolin, Rovelli, Penrose)does not seem to address deep philosophical issues (?)never solved or addressed the measurement problem
All known string theories are perturbation theories
String solutions are unstable (?)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Some reasons not to. . . love it
String theory is a “glorified” QFT (and nothing more)
“a chip of the same block” as QFT has its own skeleton in thecloset
String theory:
is background dependent (Smolin, Rovelli, Penrose)does not seem to address deep philosophical issues (?)never solved or addressed the measurement problem
All known string theories are perturbation theories
String solutions are unstable (?)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Some reasons not to. . . love it
String theory is a “glorified” QFT (and nothing more)
“a chip of the same block” as QFT has its own skeleton in thecloset
String theory:
is background dependent (Smolin, Rovelli, Penrose)
does not seem to address deep philosophical issues (?)never solved or addressed the measurement problem
All known string theories are perturbation theories
String solutions are unstable (?)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Some reasons not to. . . love it
String theory is a “glorified” QFT (and nothing more)
“a chip of the same block” as QFT has its own skeleton in thecloset
String theory:
is background dependent (Smolin, Rovelli, Penrose)does not seem to address deep philosophical issues (?)
never solved or addressed the measurement problem
All known string theories are perturbation theories
String solutions are unstable (?)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Some reasons not to. . . love it
String theory is a “glorified” QFT (and nothing more)
“a chip of the same block” as QFT has its own skeleton in thecloset
String theory:
is background dependent (Smolin, Rovelli, Penrose)does not seem to address deep philosophical issues (?)never solved or addressed the measurement problem
All known string theories are perturbation theories
String solutions are unstable (?)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Some reasons not to. . . love it
String theory is a “glorified” QFT (and nothing more)
“a chip of the same block” as QFT has its own skeleton in thecloset
String theory:
is background dependent (Smolin, Rovelli, Penrose)does not seem to address deep philosophical issues (?)never solved or addressed the measurement problem
All known string theories are perturbation theories
String solutions are unstable (?)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Some reasons not to. . . love it
String theory is a “glorified” QFT (and nothing more)
“a chip of the same block” as QFT has its own skeleton in thecloset
String theory:
is background dependent (Smolin, Rovelli, Penrose)does not seem to address deep philosophical issues (?)never solved or addressed the measurement problem
All known string theories are perturbation theories
String solutions are unstable (?)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
A reason to hate it: background dependency
ST presupposes a spacetime background and by this it defiesgeneral relativity (???)
Philosophers do not like this dependency either (SeeIntroduction to ?)
So does QFT, it involves a fixed spacetime geometry (apriori?)
But this is against the very principle of general relativity.
In String Theory geometry is not dynamical anymore.
It is like the “unmoved mover” or the ether.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
A reason to hate it: background dependency
ST presupposes a spacetime background and by this it defiesgeneral relativity (???)
Philosophers do not like this dependency either (SeeIntroduction to ?)
So does QFT, it involves a fixed spacetime geometry (apriori?)
But this is against the very principle of general relativity.
In String Theory geometry is not dynamical anymore.
It is like the “unmoved mover” or the ether.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
A reason to hate it: background dependency
ST presupposes a spacetime background and by this it defiesgeneral relativity (???)
Philosophers do not like this dependency either (SeeIntroduction to ?)
So does QFT, it involves a fixed spacetime geometry (apriori?)
But this is against the very principle of general relativity.
In String Theory geometry is not dynamical anymore.
It is like the “unmoved mover” or the ether.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
A reason to hate it: background dependency
ST presupposes a spacetime background and by this it defiesgeneral relativity (???)
Philosophers do not like this dependency either (SeeIntroduction to ?)
So does QFT, it involves a fixed spacetime geometry (apriori?)
But this is against the very principle of general relativity.
In String Theory geometry is not dynamical anymore.
It is like the “unmoved mover” or the ether.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
A reason to hate it: background dependency
ST presupposes a spacetime background and by this it defiesgeneral relativity (???)
Philosophers do not like this dependency either (SeeIntroduction to ?)
So does QFT, it involves a fixed spacetime geometry (apriori?)
But this is against the very principle of general relativity.
In String Theory geometry is not dynamical anymore.
It is like the “unmoved mover” or the ether.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
A reason to hate it: background dependency
ST presupposes a spacetime background and by this it defiesgeneral relativity (???)
Philosophers do not like this dependency either (SeeIntroduction to ?)
So does QFT, it involves a fixed spacetime geometry (apriori?)
But this is against the very principle of general relativity.
In String Theory geometry is not dynamical anymore.
It is like the “unmoved mover” or the ether.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
A reason to hate it: background dependency
ST presupposes a spacetime background and by this it defiesgeneral relativity (???)
Philosophers do not like this dependency either (SeeIntroduction to ?)
So does QFT, it involves a fixed spacetime geometry (apriori?)
But this is against the very principle of general relativity.
In String Theory geometry is not dynamical anymore.
It is like the “unmoved mover” or the ether.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
The prodigal ST
“What is very frustrating is that . . . string theorydoes not seem to fully incorporate the basic lessonof GR, which is that space and time are dynamicalrather than fixed, and relational rather than absolute. . . all that happens is that some strings moveagainst this fixed background and interact with oneanother.” ((?, 159))
Roughly speaking, ST replicates the mistake of Newtonianphysics and overlooks some central achievements of GR.
i.e. it does mesh well with mature/successful/well-acceptedscientific theories.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
The prodigal ST
“What is very frustrating is that . . . string theorydoes not seem to fully incorporate the basic lessonof GR, which is that space and time are dynamicalrather than fixed, and relational rather than absolute. . . all that happens is that some strings moveagainst this fixed background and interact with oneanother.” ((?, 159))
Roughly speaking, ST replicates the mistake of Newtonianphysics and overlooks some central achievements of GR.
i.e. it does mesh well with mature/successful/well-acceptedscientific theories.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
The prodigal ST
“What is very frustrating is that . . . string theorydoes not seem to fully incorporate the basic lessonof GR, which is that space and time are dynamicalrather than fixed, and relational rather than absolute. . . all that happens is that some strings moveagainst this fixed background and interact with oneanother.” ((?, 159))
Roughly speaking, ST replicates the mistake of Newtonianphysics and overlooks some central achievements of GR.
i.e. it does mesh well with mature/successful/well-acceptedscientific theories.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
The prodigal ST
“What is very frustrating is that . . . string theorydoes not seem to fully incorporate the basic lessonof GR, which is that space and time are dynamicalrather than fixed, and relational rather than absolute. . . all that happens is that some strings moveagainst this fixed background and interact with oneanother.” ((?, 159))
Roughly speaking, ST replicates the mistake of Newtonianphysics and overlooks some central achievements of GR.
i.e. it does mesh well with mature/successful/well-acceptedscientific theories.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Bleak philosophy of string theory: confirmation andprediction
Is ST confirmed directly?
No, it is not.
Is ST successful in providing novel predictions?
No, it is not.Some predictions are in sight in “string cosmology” or stringyblack holes
I would not apply a “naive falsificationism” to string theory.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Bleak philosophy of string theory: confirmation andprediction
Is ST confirmed directly?
No, it is not.
Is ST successful in providing novel predictions?
No, it is not.Some predictions are in sight in “string cosmology” or stringyblack holes
I would not apply a “naive falsificationism” to string theory.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Bleak philosophy of string theory: confirmation andprediction
Is ST confirmed directly?
No, it is not.
Is ST successful in providing novel predictions?
No, it is not.Some predictions are in sight in “string cosmology” or stringyblack holes
I would not apply a “naive falsificationism” to string theory.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Bleak philosophy of string theory: confirmation andprediction
Is ST confirmed directly?
No, it is not.
Is ST successful in providing novel predictions?
No, it is not.
Some predictions are in sight in “string cosmology” or stringyblack holes
I would not apply a “naive falsificationism” to string theory.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Bleak philosophy of string theory: confirmation andprediction
Is ST confirmed directly?
No, it is not.
Is ST successful in providing novel predictions?
No, it is not.Some predictions are in sight in “string cosmology” or stringyblack holes
I would not apply a “naive falsificationism” to string theory.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Bleak philosophy of string theory: confirmation andprediction
Is ST confirmed directly?
No, it is not.
Is ST successful in providing novel predictions?
No, it is not.Some predictions are in sight in “string cosmology” or stringyblack holes
I would not apply a “naive falsificationism” to string theory.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Apply GOF falsificationism to string theory?
No data, no falsification, no science
Hence string theory is closer to:
MathematicsMetaphysicsSpeculationMysticism, new-age cults or even religion (it creates its ownlingo).
Some deemed ST (and QG) as “postmodern physics”(Nambu)
Several physicists aired these worries: L. Smolin, P. Woit, R.Penrose
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Apply GOF falsificationism to string theory?
No data, no falsification, no science
Hence string theory is closer to:
MathematicsMetaphysicsSpeculationMysticism, new-age cults or even religion (it creates its ownlingo).
Some deemed ST (and QG) as “postmodern physics”(Nambu)
Several physicists aired these worries: L. Smolin, P. Woit, R.Penrose
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Apply GOF falsificationism to string theory?
No data, no falsification, no science
Hence string theory is closer to:
MathematicsMetaphysicsSpeculationMysticism, new-age cults or even religion (it creates its ownlingo).
Some deemed ST (and QG) as “postmodern physics”(Nambu)
Several physicists aired these worries: L. Smolin, P. Woit, R.Penrose
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Apply GOF falsificationism to string theory?
No data, no falsification, no science
Hence string theory is closer to:
Mathematics
MetaphysicsSpeculationMysticism, new-age cults or even religion (it creates its ownlingo).
Some deemed ST (and QG) as “postmodern physics”(Nambu)
Several physicists aired these worries: L. Smolin, P. Woit, R.Penrose
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Apply GOF falsificationism to string theory?
No data, no falsification, no science
Hence string theory is closer to:
MathematicsMetaphysics
SpeculationMysticism, new-age cults or even religion (it creates its ownlingo).
Some deemed ST (and QG) as “postmodern physics”(Nambu)
Several physicists aired these worries: L. Smolin, P. Woit, R.Penrose
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Apply GOF falsificationism to string theory?
No data, no falsification, no science
Hence string theory is closer to:
MathematicsMetaphysicsSpeculation
Mysticism, new-age cults or even religion (it creates its ownlingo).
Some deemed ST (and QG) as “postmodern physics”(Nambu)
Several physicists aired these worries: L. Smolin, P. Woit, R.Penrose
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Apply GOF falsificationism to string theory?
No data, no falsification, no science
Hence string theory is closer to:
MathematicsMetaphysicsSpeculationMysticism, new-age cults or even religion (it creates its ownlingo).
Some deemed ST (and QG) as “postmodern physics”(Nambu)
Several physicists aired these worries: L. Smolin, P. Woit, R.Penrose
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Apply GOF falsificationism to string theory?
No data, no falsification, no science
Hence string theory is closer to:
MathematicsMetaphysicsSpeculationMysticism, new-age cults or even religion (it creates its ownlingo).
Some deemed ST (and QG) as “postmodern physics”(Nambu)
Several physicists aired these worries: L. Smolin, P. Woit, R.Penrose
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Apply GOF falsificationism to string theory?
No data, no falsification, no science
Hence string theory is closer to:
MathematicsMetaphysicsSpeculationMysticism, new-age cults or even religion (it creates its ownlingo).
Some deemed ST (and QG) as “postmodern physics”(Nambu)
Several physicists aired these worries: L. Smolin, P. Woit, R.Penrose
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Apply GOF falsificationism to string theory?
No data, no falsification, no science
Hence string theory is closer to:
MathematicsMetaphysicsSpeculationMysticism, new-age cults or even religion (it creates its ownlingo).
Some deemed ST (and QG) as “postmodern physics”(Nambu)
Several physicists aired these worries: L. Smolin, P. Woit, R.Penrose
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Experimental agnosticism
Stay agnostic about its direct experimental confirmation
“Test me if you can!”
Credits go tohttp://icanhascheeseburger.com
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Experimental agnosticism
Stay agnostic about its direct experimental confirmation
“Test me if you can!”
Credits go tohttp://icanhascheeseburger.com
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Experimental agnosticism
Stay agnostic about its direct experimental confirmation
“Test me if you can!”
Credits go tohttp://icanhascheeseburger.com
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Experimental agnosticism
Stay agnostic about its direct experimental confirmation
“Test me if you can!”
Credits go tohttp://icanhascheeseburger.com
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Less bleak philosophy of string theory: some virtues
What theoretical dimensions of scientific success are known?
1 Unification2 Explanation3 Elegancy, Cohesion, Beauty, Simplicity, you name it. . .4 Problem Solving
1 is obvious and recognized as such (but deserves attention,too)
3 difficult to define, vague, ambiguous
4 is a interesting topic in itself (Ex: string and anomalies)
Here I tackle 2 and relatedly, 1.
Why 2?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Less bleak philosophy of string theory: some virtues
What theoretical dimensions of scientific success are known?
1 Unification2 Explanation3 Elegancy, Cohesion, Beauty, Simplicity, you name it. . .4 Problem Solving
1 is obvious and recognized as such (but deserves attention,too)
3 difficult to define, vague, ambiguous
4 is a interesting topic in itself (Ex: string and anomalies)
Here I tackle 2 and relatedly, 1.
Why 2?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Less bleak philosophy of string theory: some virtues
What theoretical dimensions of scientific success are known?1 Unification
2 Explanation3 Elegancy, Cohesion, Beauty, Simplicity, you name it. . .4 Problem Solving
1 is obvious and recognized as such (but deserves attention,too)
3 difficult to define, vague, ambiguous
4 is a interesting topic in itself (Ex: string and anomalies)
Here I tackle 2 and relatedly, 1.
Why 2?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Less bleak philosophy of string theory: some virtues
What theoretical dimensions of scientific success are known?1 Unification2 Explanation
3 Elegancy, Cohesion, Beauty, Simplicity, you name it. . .4 Problem Solving
1 is obvious and recognized as such (but deserves attention,too)
3 difficult to define, vague, ambiguous
4 is a interesting topic in itself (Ex: string and anomalies)
Here I tackle 2 and relatedly, 1.
Why 2?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Less bleak philosophy of string theory: some virtues
What theoretical dimensions of scientific success are known?1 Unification2 Explanation3 Elegancy, Cohesion, Beauty, Simplicity, you name it. . .
4 Problem Solving
1 is obvious and recognized as such (but deserves attention,too)
3 difficult to define, vague, ambiguous
4 is a interesting topic in itself (Ex: string and anomalies)
Here I tackle 2 and relatedly, 1.
Why 2?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Less bleak philosophy of string theory: some virtues
What theoretical dimensions of scientific success are known?1 Unification2 Explanation3 Elegancy, Cohesion, Beauty, Simplicity, you name it. . .4 Problem Solving
1 is obvious and recognized as such (but deserves attention,too)
3 difficult to define, vague, ambiguous
4 is a interesting topic in itself (Ex: string and anomalies)
Here I tackle 2 and relatedly, 1.
Why 2?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Less bleak philosophy of string theory: some virtues
What theoretical dimensions of scientific success are known?1 Unification2 Explanation3 Elegancy, Cohesion, Beauty, Simplicity, you name it. . .4 Problem Solving
1 is obvious and recognized as such (but deserves attention,too)
3 difficult to define, vague, ambiguous
4 is a interesting topic in itself (Ex: string and anomalies)
Here I tackle 2 and relatedly, 1.
Why 2?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Less bleak philosophy of string theory: some virtues
What theoretical dimensions of scientific success are known?1 Unification2 Explanation3 Elegancy, Cohesion, Beauty, Simplicity, you name it. . .4 Problem Solving
1 is obvious and recognized as such (but deserves attention,too)
3 difficult to define, vague, ambiguous
4 is a interesting topic in itself (Ex: string and anomalies)
Here I tackle 2 and relatedly, 1.
Why 2?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Less bleak philosophy of string theory: some virtues
What theoretical dimensions of scientific success are known?1 Unification2 Explanation3 Elegancy, Cohesion, Beauty, Simplicity, you name it. . .4 Problem Solving
1 is obvious and recognized as such (but deserves attention,too)
3 difficult to define, vague, ambiguous
4 is a interesting topic in itself (Ex: string and anomalies)
Here I tackle 2 and relatedly, 1.
Why 2?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Less bleak philosophy of string theory: some virtues
What theoretical dimensions of scientific success are known?1 Unification2 Explanation3 Elegancy, Cohesion, Beauty, Simplicity, you name it. . .4 Problem Solving
1 is obvious and recognized as such (but deserves attention,too)
3 difficult to define, vague, ambiguous
4 is a interesting topic in itself (Ex: string and anomalies)
Here I tackle 2 and relatedly, 1.
Why 2?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Less bleak philosophy of string theory: some virtues
What theoretical dimensions of scientific success are known?1 Unification2 Explanation3 Elegancy, Cohesion, Beauty, Simplicity, you name it. . .4 Problem Solving
1 is obvious and recognized as such (but deserves attention,too)
3 difficult to define, vague, ambiguous
4 is a interesting topic in itself (Ex: string and anomalies)
Here I tackle 2 and relatedly, 1.
Why 2?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Does string theory “latch onto reality”? If so, how?
If string explanation is succesful, one can try to run an“inference from the best explanation”.
But this inference needs to be precedeed by an analysis of thesurplus structure of string theory.
Other related questions:
Is ST or is it not “non-referential”?Do we have reasons to believe in the reality of strings (orbranes or whatever?)What reason do we have to embrace a “string realism”?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Does string theory “latch onto reality”? If so, how?
If string explanation is succesful, one can try to run an“inference from the best explanation”.
But this inference needs to be precedeed by an analysis of thesurplus structure of string theory.
Other related questions:
Is ST or is it not “non-referential”?Do we have reasons to believe in the reality of strings (orbranes or whatever?)What reason do we have to embrace a “string realism”?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Does string theory “latch onto reality”? If so, how?
If string explanation is succesful, one can try to run an“inference from the best explanation”.
But this inference needs to be precedeed by an analysis of thesurplus structure of string theory.
Other related questions:
Is ST or is it not “non-referential”?Do we have reasons to believe in the reality of strings (orbranes or whatever?)What reason do we have to embrace a “string realism”?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Does string theory “latch onto reality”? If so, how?
If string explanation is succesful, one can try to run an“inference from the best explanation”.
But this inference needs to be precedeed by an analysis of thesurplus structure of string theory.
Other related questions:
Is ST or is it not “non-referential”?Do we have reasons to believe in the reality of strings (orbranes or whatever?)What reason do we have to embrace a “string realism”?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Does string theory “latch onto reality”? If so, how?
If string explanation is succesful, one can try to run an“inference from the best explanation”.
But this inference needs to be precedeed by an analysis of thesurplus structure of string theory.
Other related questions:
Is ST or is it not “non-referential”?
Do we have reasons to believe in the reality of strings (orbranes or whatever?)What reason do we have to embrace a “string realism”?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Does string theory “latch onto reality”? If so, how?
If string explanation is succesful, one can try to run an“inference from the best explanation”.
But this inference needs to be precedeed by an analysis of thesurplus structure of string theory.
Other related questions:
Is ST or is it not “non-referential”?Do we have reasons to believe in the reality of strings (orbranes or whatever?)
What reason do we have to embrace a “string realism”?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
Does string theory “latch onto reality”? If so, how?
If string explanation is succesful, one can try to run an“inference from the best explanation”.
But this inference needs to be precedeed by an analysis of thesurplus structure of string theory.
Other related questions:
Is ST or is it not “non-referential”?Do we have reasons to believe in the reality of strings (orbranes or whatever?)What reason do we have to embrace a “string realism”?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
What is needed in the metaphysics of string theory?
As in QM or QFT, we cannot “read off” the ontology fromtheir equations
Hard to differentiate the surplus from the real elements of thetheory.
We cannot cherry-pick the equations and interpret them
Differentiate explanatory fictions from real explanatory entities
Perhaps we need some lessons from mainstream metaphysicsabout fundamentality.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
What is needed in the metaphysics of string theory?
As in QM or QFT, we cannot “read off” the ontology fromtheir equations
Hard to differentiate the surplus from the real elements of thetheory.
We cannot cherry-pick the equations and interpret them
Differentiate explanatory fictions from real explanatory entities
Perhaps we need some lessons from mainstream metaphysicsabout fundamentality.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
What is needed in the metaphysics of string theory?
As in QM or QFT, we cannot “read off” the ontology fromtheir equations
Hard to differentiate the surplus from the real elements of thetheory.
We cannot cherry-pick the equations and interpret them
Differentiate explanatory fictions from real explanatory entities
Perhaps we need some lessons from mainstream metaphysicsabout fundamentality.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
What is needed in the metaphysics of string theory?
As in QM or QFT, we cannot “read off” the ontology fromtheir equations
Hard to differentiate the surplus from the real elements of thetheory.
We cannot cherry-pick the equations and interpret them
Differentiate explanatory fictions from real explanatory entities
Perhaps we need some lessons from mainstream metaphysicsabout fundamentality.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
What is needed in the metaphysics of string theory?
As in QM or QFT, we cannot “read off” the ontology fromtheir equations
Hard to differentiate the surplus from the real elements of thetheory.
We cannot cherry-pick the equations and interpret them
Differentiate explanatory fictions from real explanatory entities
Perhaps we need some lessons from mainstream metaphysicsabout fundamentality.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Two stancesPhilosophy of Science and String TheoryString metaphysics?
What is needed in the metaphysics of string theory?
As in QM or QFT, we cannot “read off” the ontology fromtheir equations
Hard to differentiate the surplus from the real elements of thetheory.
We cannot cherry-pick the equations and interpret them
Differentiate explanatory fictions from real explanatory entities
Perhaps we need some lessons from mainstream metaphysicsabout fundamentality.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
My proposal
Look at the explanatory store of String Theory: what isexplained?Primarily, I argue, string theory explains features of othertheories:
1 Constants and Parameters: Newton’s constant;2 Structures: the fermion-boson duality of the Standard Model,
the group structure of the Standard Model;3 The gauge nature of General Relativity;4 Facts which are taken as “brute” in other theories;5 Its own limitations: inconsistencies, incompleteness.
At this stage, it does not directly explain facts about/fromthe worldTherefore, “string explanation” is mainly an inter-theoreticalrelationPerhaps it is a new type of explanation: the string explanation
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
My proposal
Look at the explanatory store of String Theory: what isexplained?
Primarily, I argue, string theory explains features of othertheories:
1 Constants and Parameters: Newton’s constant;2 Structures: the fermion-boson duality of the Standard Model,
the group structure of the Standard Model;3 The gauge nature of General Relativity;4 Facts which are taken as “brute” in other theories;5 Its own limitations: inconsistencies, incompleteness.
At this stage, it does not directly explain facts about/fromthe worldTherefore, “string explanation” is mainly an inter-theoreticalrelationPerhaps it is a new type of explanation: the string explanation
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
My proposal
Look at the explanatory store of String Theory: what isexplained?Primarily, I argue, string theory explains features of othertheories:
1 Constants and Parameters: Newton’s constant;2 Structures: the fermion-boson duality of the Standard Model,
the group structure of the Standard Model;3 The gauge nature of General Relativity;4 Facts which are taken as “brute” in other theories;5 Its own limitations: inconsistencies, incompleteness.
At this stage, it does not directly explain facts about/fromthe worldTherefore, “string explanation” is mainly an inter-theoreticalrelationPerhaps it is a new type of explanation: the string explanation
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
My proposal
Look at the explanatory store of String Theory: what isexplained?Primarily, I argue, string theory explains features of othertheories:
1 Constants and Parameters: Newton’s constant;
2 Structures: the fermion-boson duality of the Standard Model,the group structure of the Standard Model;
3 The gauge nature of General Relativity;4 Facts which are taken as “brute” in other theories;5 Its own limitations: inconsistencies, incompleteness.
At this stage, it does not directly explain facts about/fromthe worldTherefore, “string explanation” is mainly an inter-theoreticalrelationPerhaps it is a new type of explanation: the string explanation
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
My proposal
Look at the explanatory store of String Theory: what isexplained?Primarily, I argue, string theory explains features of othertheories:
1 Constants and Parameters: Newton’s constant;2 Structures: the fermion-boson duality of the Standard Model,
the group structure of the Standard Model;
3 The gauge nature of General Relativity;4 Facts which are taken as “brute” in other theories;5 Its own limitations: inconsistencies, incompleteness.
At this stage, it does not directly explain facts about/fromthe worldTherefore, “string explanation” is mainly an inter-theoreticalrelationPerhaps it is a new type of explanation: the string explanation
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
My proposal
Look at the explanatory store of String Theory: what isexplained?Primarily, I argue, string theory explains features of othertheories:
1 Constants and Parameters: Newton’s constant;2 Structures: the fermion-boson duality of the Standard Model,
the group structure of the Standard Model;3 The gauge nature of General Relativity;
4 Facts which are taken as “brute” in other theories;5 Its own limitations: inconsistencies, incompleteness.
At this stage, it does not directly explain facts about/fromthe worldTherefore, “string explanation” is mainly an inter-theoreticalrelationPerhaps it is a new type of explanation: the string explanation
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
My proposal
Look at the explanatory store of String Theory: what isexplained?Primarily, I argue, string theory explains features of othertheories:
1 Constants and Parameters: Newton’s constant;2 Structures: the fermion-boson duality of the Standard Model,
the group structure of the Standard Model;3 The gauge nature of General Relativity;4 Facts which are taken as “brute” in other theories;
5 Its own limitations: inconsistencies, incompleteness.
At this stage, it does not directly explain facts about/fromthe worldTherefore, “string explanation” is mainly an inter-theoreticalrelationPerhaps it is a new type of explanation: the string explanation
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
My proposal
Look at the explanatory store of String Theory: what isexplained?Primarily, I argue, string theory explains features of othertheories:
1 Constants and Parameters: Newton’s constant;2 Structures: the fermion-boson duality of the Standard Model,
the group structure of the Standard Model;3 The gauge nature of General Relativity;4 Facts which are taken as “brute” in other theories;5 Its own limitations: inconsistencies, incompleteness.
At this stage, it does not directly explain facts about/fromthe worldTherefore, “string explanation” is mainly an inter-theoreticalrelationPerhaps it is a new type of explanation: the string explanation
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
My proposal
Look at the explanatory store of String Theory: what isexplained?Primarily, I argue, string theory explains features of othertheories:
1 Constants and Parameters: Newton’s constant;2 Structures: the fermion-boson duality of the Standard Model,
the group structure of the Standard Model;3 The gauge nature of General Relativity;4 Facts which are taken as “brute” in other theories;5 Its own limitations: inconsistencies, incompleteness.
At this stage, it does not directly explain facts about/fromthe world
Therefore, “string explanation” is mainly an inter-theoreticalrelationPerhaps it is a new type of explanation: the string explanation
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
My proposal
Look at the explanatory store of String Theory: what isexplained?Primarily, I argue, string theory explains features of othertheories:
1 Constants and Parameters: Newton’s constant;2 Structures: the fermion-boson duality of the Standard Model,
the group structure of the Standard Model;3 The gauge nature of General Relativity;4 Facts which are taken as “brute” in other theories;5 Its own limitations: inconsistencies, incompleteness.
At this stage, it does not directly explain facts about/fromthe worldTherefore, “string explanation” is mainly an inter-theoreticalrelation
Perhaps it is a new type of explanation: the string explanation
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
My proposal
Look at the explanatory store of String Theory: what isexplained?Primarily, I argue, string theory explains features of othertheories:
1 Constants and Parameters: Newton’s constant;2 Structures: the fermion-boson duality of the Standard Model,
the group structure of the Standard Model;3 The gauge nature of General Relativity;4 Facts which are taken as “brute” in other theories;5 Its own limitations: inconsistencies, incompleteness.
At this stage, it does not directly explain facts about/fromthe worldTherefore, “string explanation” is mainly an inter-theoreticalrelationPerhaps it is a new type of explanation: the string explanationIoan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
String Explanation: another bleak philosophy?
Gut reaction: “nothing new under the Sun”! Integrate Stringexplanations in the existing models of explanation.
What kind of explanation is at work in string theory?Option 1: The D-N model
Are there laws/generalizations in String Theory?Do we have facts to “explain”?Do we have facts to use in the D-N explanation?
Arguably, string theory does not have principles or lawsOption 2: Causal model of explanation
No chance to see causation at work at this level
Option 3: Mathematical explanations
Option 4: Explanations based on unification
Option 5: Functional explanations from symmetry
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
String Explanation: another bleak philosophy?
Gut reaction: “nothing new under the Sun”! Integrate Stringexplanations in the existing models of explanation.
What kind of explanation is at work in string theory?
Option 1: The D-N model
Are there laws/generalizations in String Theory?Do we have facts to “explain”?Do we have facts to use in the D-N explanation?
Arguably, string theory does not have principles or lawsOption 2: Causal model of explanation
No chance to see causation at work at this level
Option 3: Mathematical explanations
Option 4: Explanations based on unification
Option 5: Functional explanations from symmetry
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
String Explanation: another bleak philosophy?
Gut reaction: “nothing new under the Sun”! Integrate Stringexplanations in the existing models of explanation.
What kind of explanation is at work in string theory?Option 1: The D-N model
Are there laws/generalizations in String Theory?Do we have facts to “explain”?Do we have facts to use in the D-N explanation?
Arguably, string theory does not have principles or lawsOption 2: Causal model of explanation
No chance to see causation at work at this level
Option 3: Mathematical explanations
Option 4: Explanations based on unification
Option 5: Functional explanations from symmetry
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
String Explanation: another bleak philosophy?
Gut reaction: “nothing new under the Sun”! Integrate Stringexplanations in the existing models of explanation.
What kind of explanation is at work in string theory?Option 1: The D-N model
Are there laws/generalizations in String Theory?
Do we have facts to “explain”?Do we have facts to use in the D-N explanation?
Arguably, string theory does not have principles or lawsOption 2: Causal model of explanation
No chance to see causation at work at this level
Option 3: Mathematical explanations
Option 4: Explanations based on unification
Option 5: Functional explanations from symmetry
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
String Explanation: another bleak philosophy?
Gut reaction: “nothing new under the Sun”! Integrate Stringexplanations in the existing models of explanation.
What kind of explanation is at work in string theory?Option 1: The D-N model
Are there laws/generalizations in String Theory?Do we have facts to “explain”?
Do we have facts to use in the D-N explanation?
Arguably, string theory does not have principles or lawsOption 2: Causal model of explanation
No chance to see causation at work at this level
Option 3: Mathematical explanations
Option 4: Explanations based on unification
Option 5: Functional explanations from symmetry
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
String Explanation: another bleak philosophy?
Gut reaction: “nothing new under the Sun”! Integrate Stringexplanations in the existing models of explanation.
What kind of explanation is at work in string theory?Option 1: The D-N model
Are there laws/generalizations in String Theory?Do we have facts to “explain”?Do we have facts to use in the D-N explanation?
Arguably, string theory does not have principles or lawsOption 2: Causal model of explanation
No chance to see causation at work at this level
Option 3: Mathematical explanations
Option 4: Explanations based on unification
Option 5: Functional explanations from symmetry
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
String Explanation: another bleak philosophy?
Gut reaction: “nothing new under the Sun”! Integrate Stringexplanations in the existing models of explanation.
What kind of explanation is at work in string theory?Option 1: The D-N model
Are there laws/generalizations in String Theory?Do we have facts to “explain”?Do we have facts to use in the D-N explanation?
Arguably, string theory does not have principles or laws
Option 2: Causal model of explanation
No chance to see causation at work at this level
Option 3: Mathematical explanations
Option 4: Explanations based on unification
Option 5: Functional explanations from symmetry
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
String Explanation: another bleak philosophy?
Gut reaction: “nothing new under the Sun”! Integrate Stringexplanations in the existing models of explanation.
What kind of explanation is at work in string theory?Option 1: The D-N model
Are there laws/generalizations in String Theory?Do we have facts to “explain”?Do we have facts to use in the D-N explanation?
Arguably, string theory does not have principles or lawsOption 2: Causal model of explanation
No chance to see causation at work at this level
Option 3: Mathematical explanations
Option 4: Explanations based on unification
Option 5: Functional explanations from symmetry
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
String Explanation: another bleak philosophy?
Gut reaction: “nothing new under the Sun”! Integrate Stringexplanations in the existing models of explanation.
What kind of explanation is at work in string theory?Option 1: The D-N model
Are there laws/generalizations in String Theory?Do we have facts to “explain”?Do we have facts to use in the D-N explanation?
Arguably, string theory does not have principles or lawsOption 2: Causal model of explanation
No chance to see causation at work at this level
Option 3: Mathematical explanations
Option 4: Explanations based on unification
Option 5: Functional explanations from symmetry
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
String Explanation: another bleak philosophy?
Gut reaction: “nothing new under the Sun”! Integrate Stringexplanations in the existing models of explanation.
What kind of explanation is at work in string theory?Option 1: The D-N model
Are there laws/generalizations in String Theory?Do we have facts to “explain”?Do we have facts to use in the D-N explanation?
Arguably, string theory does not have principles or lawsOption 2: Causal model of explanation
No chance to see causation at work at this level
Option 3: Mathematical explanations
Option 4: Explanations based on unification
Option 5: Functional explanations from symmetry
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
String Explanation: another bleak philosophy?
Gut reaction: “nothing new under the Sun”! Integrate Stringexplanations in the existing models of explanation.
What kind of explanation is at work in string theory?Option 1: The D-N model
Are there laws/generalizations in String Theory?Do we have facts to “explain”?Do we have facts to use in the D-N explanation?
Arguably, string theory does not have principles or lawsOption 2: Causal model of explanation
No chance to see causation at work at this level
Option 3: Mathematical explanations
Option 4: Explanations based on unification
Option 5: Functional explanations from symmetry
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
String Explanation: another bleak philosophy?
Gut reaction: “nothing new under the Sun”! Integrate Stringexplanations in the existing models of explanation.
What kind of explanation is at work in string theory?Option 1: The D-N model
Are there laws/generalizations in String Theory?Do we have facts to “explain”?Do we have facts to use in the D-N explanation?
Arguably, string theory does not have principles or lawsOption 2: Causal model of explanation
No chance to see causation at work at this level
Option 3: Mathematical explanations
Option 4: Explanations based on unification
Option 5: Functional explanations from symmetry
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
Does string unification entail string explanation?
Some unificatory elements of string theory play explanatoryroles
I argue here that string explanation is also independent ofunification
The elements that do not unify but explain are constraints ofthe models
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
Does string unification entail string explanation?
Some unificatory elements of string theory play explanatoryroles
I argue here that string explanation is also independent ofunification
The elements that do not unify but explain are constraints ofthe models
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
Does string unification entail string explanation?
Some unificatory elements of string theory play explanatoryroles
I argue here that string explanation is also independent ofunification
The elements that do not unify but explain are constraints ofthe models
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
Can constraints explain?
String theory is a mathematical model of the dynamics ofstrings
Which elements play the explanatory role?
Unlike other cases, I do not couple here unification andexplanation–not that strongly
String explanation is independent of unificationhistorically they came at different moments
Both physical and mathematical constraints explainMathematical constraints
String theory should render the probabilities of quantum eventsin the interval [0, 1]
I place string explanation at the intersection of unification andmathematical formalism.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
Can constraints explain?
String theory is a mathematical model of the dynamics ofstringsWhich elements play the explanatory role?
Unlike other cases, I do not couple here unification andexplanation–not that strongly
String explanation is independent of unificationhistorically they came at different moments
Both physical and mathematical constraints explainMathematical constraints
String theory should render the probabilities of quantum eventsin the interval [0, 1]
I place string explanation at the intersection of unification andmathematical formalism.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
Can constraints explain?
String theory is a mathematical model of the dynamics ofstringsWhich elements play the explanatory role?
Unlike other cases, I do not couple here unification andexplanation–not that strongly
String explanation is independent of unificationhistorically they came at different moments
Both physical and mathematical constraints explainMathematical constraints
String theory should render the probabilities of quantum eventsin the interval [0, 1]
I place string explanation at the intersection of unification andmathematical formalism.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
Can constraints explain?
String theory is a mathematical model of the dynamics ofstringsWhich elements play the explanatory role?
Unlike other cases, I do not couple here unification andexplanation–not that strongly
String explanation is independent of unificationhistorically they came at different moments
Both physical and mathematical constraints explainMathematical constraints
String theory should render the probabilities of quantum eventsin the interval [0, 1]
I place string explanation at the intersection of unification andmathematical formalism.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
Can constraints explain?
String theory is a mathematical model of the dynamics ofstringsWhich elements play the explanatory role?
Unlike other cases, I do not couple here unification andexplanation–not that strongly
String explanation is independent of unification
historically they came at different moments
Both physical and mathematical constraints explainMathematical constraints
String theory should render the probabilities of quantum eventsin the interval [0, 1]
I place string explanation at the intersection of unification andmathematical formalism.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
Can constraints explain?
String theory is a mathematical model of the dynamics ofstringsWhich elements play the explanatory role?
Unlike other cases, I do not couple here unification andexplanation–not that strongly
String explanation is independent of unificationhistorically they came at different moments
Both physical and mathematical constraints explainMathematical constraints
String theory should render the probabilities of quantum eventsin the interval [0, 1]
I place string explanation at the intersection of unification andmathematical formalism.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
Can constraints explain?
String theory is a mathematical model of the dynamics ofstringsWhich elements play the explanatory role?
Unlike other cases, I do not couple here unification andexplanation–not that strongly
String explanation is independent of unificationhistorically they came at different moments
Both physical and mathematical constraints explain
Mathematical constraints
String theory should render the probabilities of quantum eventsin the interval [0, 1]
I place string explanation at the intersection of unification andmathematical formalism.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
Can constraints explain?
String theory is a mathematical model of the dynamics ofstringsWhich elements play the explanatory role?
Unlike other cases, I do not couple here unification andexplanation–not that strongly
String explanation is independent of unificationhistorically they came at different moments
Both physical and mathematical constraints explainMathematical constraints
String theory should render the probabilities of quantum eventsin the interval [0, 1]
I place string explanation at the intersection of unification andmathematical formalism.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
Can constraints explain?
String theory is a mathematical model of the dynamics ofstringsWhich elements play the explanatory role?
Unlike other cases, I do not couple here unification andexplanation–not that strongly
String explanation is independent of unificationhistorically they came at different moments
Both physical and mathematical constraints explainMathematical constraints
String theory should render the probabilities of quantum eventsin the interval [0, 1]
I place string explanation at the intersection of unification andmathematical formalism.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
String Explanations
Can constraints explain?
String theory is a mathematical model of the dynamics ofstringsWhich elements play the explanatory role?
Unlike other cases, I do not couple here unification andexplanation–not that strongly
String explanation is independent of unificationhistorically they came at different moments
Both physical and mathematical constraints explainMathematical constraints
String theory should render the probabilities of quantum eventsin the interval [0, 1]
I place string explanation at the intersection of unification andmathematical formalism.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
QG: What is at stake?
CONT: Spacetime is continuous
POINTS: Fundamental entities are pointlike particles
BACKGROUND: Fundamental entities move in a fixedbackground spacetime
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
QG: What is at stake?
CONT: Spacetime is continuous
POINTS: Fundamental entities are pointlike particles
BACKGROUND: Fundamental entities move in a fixedbackground spacetime
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
QG: What is at stake?
CONT: Spacetime is continuous
POINTS: Fundamental entities are pointlike particles
BACKGROUND: Fundamental entities move in a fixedbackground spacetime
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
QG: What is at stake?
CONT: Spacetime is continuous
POINTS: Fundamental entities are pointlike particles
BACKGROUND: Fundamental entities move in a fixedbackground spacetime
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Loop quantum gravity
Denies:
BACKGROUND (in the letter and the spirit of GR),CONT (assumes discrete manifolds).
Assumes (tacitly):
POINTLIKE
Loops are fundamental entities
The relations among loops define spacetime (no BACKGROUND
needed)
Geometry is discrete.
See C. Rovelli, L. Smolin, A. Ashtekar etc.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Loop quantum gravity
Denies:
BACKGROUND (in the letter and the spirit of GR),CONT (assumes discrete manifolds).
Assumes (tacitly):
POINTLIKE
Loops are fundamental entities
The relations among loops define spacetime (no BACKGROUND
needed)
Geometry is discrete.
See C. Rovelli, L. Smolin, A. Ashtekar etc.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Loop quantum gravity
Denies:
BACKGROUND (in the letter and the spirit of GR),
CONT (assumes discrete manifolds).
Assumes (tacitly):
POINTLIKE
Loops are fundamental entities
The relations among loops define spacetime (no BACKGROUND
needed)
Geometry is discrete.
See C. Rovelli, L. Smolin, A. Ashtekar etc.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Loop quantum gravity
Denies:
BACKGROUND (in the letter and the spirit of GR),CONT (assumes discrete manifolds).
Assumes (tacitly):
POINTLIKE
Loops are fundamental entities
The relations among loops define spacetime (no BACKGROUND
needed)
Geometry is discrete.
See C. Rovelli, L. Smolin, A. Ashtekar etc.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Loop quantum gravity
Denies:
BACKGROUND (in the letter and the spirit of GR),CONT (assumes discrete manifolds).
Assumes (tacitly):
POINTLIKE
Loops are fundamental entities
The relations among loops define spacetime (no BACKGROUND
needed)
Geometry is discrete.
See C. Rovelli, L. Smolin, A. Ashtekar etc.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Loop quantum gravity
Denies:
BACKGROUND (in the letter and the spirit of GR),CONT (assumes discrete manifolds).
Assumes (tacitly):
POINTLIKE
Loops are fundamental entities
The relations among loops define spacetime (no BACKGROUND
needed)
Geometry is discrete.
See C. Rovelli, L. Smolin, A. Ashtekar etc.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Loop quantum gravity
Denies:
BACKGROUND (in the letter and the spirit of GR),CONT (assumes discrete manifolds).
Assumes (tacitly):
POINTLIKE
Loops are fundamental entities
The relations among loops define spacetime (no BACKGROUND
needed)
Geometry is discrete.
See C. Rovelli, L. Smolin, A. Ashtekar etc.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Loop quantum gravity
Denies:
BACKGROUND (in the letter and the spirit of GR),CONT (assumes discrete manifolds).
Assumes (tacitly):
POINTLIKE
Loops are fundamental entities
The relations among loops define spacetime (no BACKGROUND
needed)
Geometry is discrete.
See C. Rovelli, L. Smolin, A. Ashtekar etc.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Loop quantum gravity
Denies:
BACKGROUND (in the letter and the spirit of GR),CONT (assumes discrete manifolds).
Assumes (tacitly):
POINTLIKE
Loops are fundamental entities
The relations among loops define spacetime (no BACKGROUND
needed)
Geometry is discrete.
See C. Rovelli, L. Smolin, A. Ashtekar etc.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Loop quantum gravity
Denies:
BACKGROUND (in the letter and the spirit of GR),CONT (assumes discrete manifolds).
Assumes (tacitly):
POINTLIKE
Loops are fundamental entities
The relations among loops define spacetime (no BACKGROUND
needed)
Geometry is discrete.
See C. Rovelli, L. Smolin, A. Ashtekar etc.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
String theory
Keeps:
(provisionally. . . ) BACKGROUNDtacitly CONT
Note: ways to combine NOT CONT with NOT POINTLIKE
Denies (strongly):
POINTLIKE
In other words, the fundamental nature of the world resemblesmore spaghetti/pasta than balls.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
String theory
Keeps:
(provisionally. . . ) BACKGROUNDtacitly CONT
Note: ways to combine NOT CONT with NOT POINTLIKE
Denies (strongly):
POINTLIKE
In other words, the fundamental nature of the world resemblesmore spaghetti/pasta than balls.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
String theory
Keeps:
(provisionally. . . ) BACKGROUND
tacitly CONT
Note: ways to combine NOT CONT with NOT POINTLIKE
Denies (strongly):
POINTLIKE
In other words, the fundamental nature of the world resemblesmore spaghetti/pasta than balls.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
String theory
Keeps:
(provisionally. . . ) BACKGROUNDtacitly CONT
Note: ways to combine NOT CONT with NOT POINTLIKE
Denies (strongly):
POINTLIKE
In other words, the fundamental nature of the world resemblesmore spaghetti/pasta than balls.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
String theory
Keeps:
(provisionally. . . ) BACKGROUNDtacitly CONT
Note: ways to combine NOT CONT with NOT POINTLIKE
Denies (strongly):
POINTLIKE
In other words, the fundamental nature of the world resemblesmore spaghetti/pasta than balls.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
String theory
Keeps:
(provisionally. . . ) BACKGROUNDtacitly CONT
Note: ways to combine NOT CONT with NOT POINTLIKE
Denies (strongly):
POINTLIKE
In other words, the fundamental nature of the world resemblesmore spaghetti/pasta than balls.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
String theory
Keeps:
(provisionally. . . ) BACKGROUNDtacitly CONT
Note: ways to combine NOT CONT with NOT POINTLIKE
Denies (strongly):
POINTLIKE
In other words, the fundamental nature of the world resemblesmore spaghetti/pasta than balls.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
String theory
Keeps:
(provisionally. . . ) BACKGROUNDtacitly CONT
Note: ways to combine NOT CONT with NOT POINTLIKE
Denies (strongly):
POINTLIKE
In other words, the fundamental nature of the world resemblesmore spaghetti/pasta than balls.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
What is advertised in QG?
Explain the nature of space and time (esp. Loop QG)
Unify GR and QM (or QFT) (esp. string theory)
Quantize gravity
Explain what happens at Planck scale (not achieved yet)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
What is advertised in QG?
Explain the nature of space and time (esp. Loop QG)
Unify GR and QM (or QFT) (esp. string theory)
Quantize gravity
Explain what happens at Planck scale (not achieved yet)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
What is advertised in QG?
Explain the nature of space and time (esp. Loop QG)
Unify GR and QM (or QFT) (esp. string theory)
Quantize gravity
Explain what happens at Planck scale (not achieved yet)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
What is advertised in QG?
Explain the nature of space and time (esp. Loop QG)
Unify GR and QM (or QFT) (esp. string theory)
Quantize gravity
Explain what happens at Planck scale (not achieved yet)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Four Assumptions
(QG-UNIF) The unification of all physical interactions,including gravity, is possible within one theory (the quantumgravity program).
(FUND) There is one fundamental entity in nature that canunify all known particles and interactions.
(SUSY) There is supersymmetry in nature.
(D>4) Physical spacetime may have a different dimensionalityand topology than the usual D=4 four-dimensional of the GR.Strings may live on subspaces of the physical spacetime andphysical interactions may be confined to some subspaces ofthe physical spacetime.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Four Assumptions
(QG-UNIF) The unification of all physical interactions,including gravity, is possible within one theory (the quantumgravity program).
(FUND) There is one fundamental entity in nature that canunify all known particles and interactions.
(SUSY) There is supersymmetry in nature.
(D>4) Physical spacetime may have a different dimensionalityand topology than the usual D=4 four-dimensional of the GR.Strings may live on subspaces of the physical spacetime andphysical interactions may be confined to some subspaces ofthe physical spacetime.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Four Assumptions
(QG-UNIF) The unification of all physical interactions,including gravity, is possible within one theory (the quantumgravity program).
(FUND) There is one fundamental entity in nature that canunify all known particles and interactions.
(SUSY) There is supersymmetry in nature.
(D>4) Physical spacetime may have a different dimensionalityand topology than the usual D=4 four-dimensional of the GR.Strings may live on subspaces of the physical spacetime andphysical interactions may be confined to some subspaces ofthe physical spacetime.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Four Assumptions
(QG-UNIF) The unification of all physical interactions,including gravity, is possible within one theory (the quantumgravity program).
(FUND) There is one fundamental entity in nature that canunify all known particles and interactions.
(SUSY) There is supersymmetry in nature.
(D>4) Physical spacetime may have a different dimensionalityand topology than the usual D=4 four-dimensional of the GR.Strings may live on subspaces of the physical spacetime andphysical interactions may be confined to some subspaces ofthe physical spacetime.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Four Assumptions
(QG-UNIF) The unification of all physical interactions,including gravity, is possible within one theory (the quantumgravity program).
(FUND) There is one fundamental entity in nature that canunify all known particles and interactions.
(SUSY) There is supersymmetry in nature.
(D>4) Physical spacetime may have a different dimensionalityand topology than the usual D=4 four-dimensional of the GR.Strings may live on subspaces of the physical spacetime andphysical interactions may be confined to some subspaces ofthe physical spacetime.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
What is denied in ST?
Denies POINTLIKE: Reality can be described by a model inwhich the fundamental objects are point-like particles amongwhich there are interactions.
Denies D=4: Point-like particles live in a spacetime with 4(3+1) dimensions (three spatial dimensions and one temporaldimension)
Denies SYM: The fundamental symmetries of the world arethose instantiated by experiments in normal/standardconditions with elementary particles.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
What is denied in ST?
Denies POINTLIKE: Reality can be described by a model inwhich the fundamental objects are point-like particles amongwhich there are interactions.
Denies D=4: Point-like particles live in a spacetime with 4(3+1) dimensions (three spatial dimensions and one temporaldimension)
Denies SYM: The fundamental symmetries of the world arethose instantiated by experiments in normal/standardconditions with elementary particles.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
What is denied in ST?
Denies POINTLIKE: Reality can be described by a model inwhich the fundamental objects are point-like particles amongwhich there are interactions.
Denies D=4: Point-like particles live in a spacetime with 4(3+1) dimensions (three spatial dimensions and one temporaldimension)
Denies SYM: The fundamental symmetries of the world arethose instantiated by experiments in normal/standardconditions with elementary particles.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
What is denied in ST?
Denies POINTLIKE: Reality can be described by a model inwhich the fundamental objects are point-like particles amongwhich there are interactions.
Denies D=4: Point-like particles live in a spacetime with 4(3+1) dimensions (three spatial dimensions and one temporaldimension)
Denies SYM: The fundamental symmetries of the world arethose instantiated by experiments in normal/standardconditions with elementary particles.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
QG-UNIF
The ideal of unification has a good support in the history ofphysics ?
We get in time more successful unifications than we get failedunifications.
optimistic meta-induction on unification
Critics admit in earnest the ST achieves unification (??).
But do we really need it? Some other QG programs do notunify (Rovelli, Weinstein)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
QG-UNIF
The ideal of unification has a good support in the history ofphysics ?
We get in time more successful unifications than we get failedunifications.
optimistic meta-induction on unification
Critics admit in earnest the ST achieves unification (??).
But do we really need it? Some other QG programs do notunify (Rovelli, Weinstein)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
QG-UNIF
The ideal of unification has a good support in the history ofphysics ?
We get in time more successful unifications than we get failedunifications.
optimistic meta-induction on unification
Critics admit in earnest the ST achieves unification (??).
But do we really need it? Some other QG programs do notunify (Rovelli, Weinstein)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
QG-UNIF
The ideal of unification has a good support in the history ofphysics ?
We get in time more successful unifications than we get failedunifications.
optimistic meta-induction on unification
Critics admit in earnest the ST achieves unification (??).
But do we really need it? Some other QG programs do notunify (Rovelli, Weinstein)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
QG-UNIF
The ideal of unification has a good support in the history ofphysics ?
We get in time more successful unifications than we get failedunifications.
optimistic meta-induction on unification
Critics admit in earnest the ST achieves unification (??).
But do we really need it? Some other QG programs do notunify (Rovelli, Weinstein)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
QG-UNIF
The ideal of unification has a good support in the history ofphysics ?
We get in time more successful unifications than we get failedunifications.
optimistic meta-induction on unification
Critics admit in earnest the ST achieves unification (??).
But do we really need it? Some other QG programs do notunify (Rovelli, Weinstein)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Unification. The headlined feature of ST
Some mantras about string theory:
1 General Relativity can be inferred from ST as a low limitenergy:
2 The Standard model, i.e. a Yang-Mills theory based on thegroup SU(3)⊗ SU(2)⊗ U(1) emerges from the theory.
Dissenters admit this as a virtue. ??
But at what price 1 and 2?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Unification. The headlined feature of ST
Some mantras about string theory:
1 General Relativity can be inferred from ST as a low limitenergy:
2 The Standard model, i.e. a Yang-Mills theory based on thegroup SU(3)⊗ SU(2)⊗ U(1) emerges from the theory.
Dissenters admit this as a virtue. ??
But at what price 1 and 2?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Unification. The headlined feature of ST
Some mantras about string theory:1 General Relativity can be inferred from ST as a low limit
energy:
2 The Standard model, i.e. a Yang-Mills theory based on thegroup SU(3)⊗ SU(2)⊗ U(1) emerges from the theory.
Dissenters admit this as a virtue. ??
But at what price 1 and 2?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Unification. The headlined feature of ST
Some mantras about string theory:1 General Relativity can be inferred from ST as a low limit
energy:2 The Standard model, i.e. a Yang-Mills theory based on the
group SU(3)⊗ SU(2)⊗ U(1) emerges from the theory.
Dissenters admit this as a virtue. ??
But at what price 1 and 2?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Unification. The headlined feature of ST
Some mantras about string theory:1 General Relativity can be inferred from ST as a low limit
energy:2 The Standard model, i.e. a Yang-Mills theory based on the
group SU(3)⊗ SU(2)⊗ U(1) emerges from the theory.
Dissenters admit this as a virtue. ??
But at what price 1 and 2?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Unification. The headlined feature of ST
Some mantras about string theory:1 General Relativity can be inferred from ST as a low limit
energy:2 The Standard model, i.e. a Yang-Mills theory based on the
group SU(3)⊗ SU(2)⊗ U(1) emerges from the theory.
Dissenters admit this as a virtue. ??
But at what price 1 and 2?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The serendipity of string theory
“General relativity is arising within the framework of aconsistent quantum theory. Ordinary QFT does not allowgravity to exist; string theory requires it.” (?, 4)
“It is striking that Einstein’s equation turns up in whatseems to be a rather out-of-the-way place, as thecondition for Weyl invariance of a two dimensional fieldtheory. String Theory provides the physical connectionbetween these two ideas.” ?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Yet another string unification: dynamics and interaction
QFT and the Standard Model have two set of laws forparticles:
PropagationsInteractions
In string theory, both propagation and interaction of particlesare explained by one set of equations.
This looks nice on paper, but in practice it involvessuper-symmetry. . .
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Yet another string unification: dynamics and interaction
QFT and the Standard Model have two set of laws forparticles:
PropagationsInteractions
In string theory, both propagation and interaction of particlesare explained by one set of equations.
This looks nice on paper, but in practice it involvessuper-symmetry. . .
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Yet another string unification: dynamics and interaction
QFT and the Standard Model have two set of laws forparticles:
Propagations
Interactions
In string theory, both propagation and interaction of particlesare explained by one set of equations.
This looks nice on paper, but in practice it involvessuper-symmetry. . .
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Yet another string unification: dynamics and interaction
QFT and the Standard Model have two set of laws forparticles:
PropagationsInteractions
In string theory, both propagation and interaction of particlesare explained by one set of equations.
This looks nice on paper, but in practice it involvessuper-symmetry. . .
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Yet another string unification: dynamics and interaction
QFT and the Standard Model have two set of laws forparticles:
PropagationsInteractions
In string theory, both propagation and interaction of particlesare explained by one set of equations.
This looks nice on paper, but in practice it involvessuper-symmetry. . .
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Yet another string unification: dynamics and interaction
QFT and the Standard Model have two set of laws forparticles:
PropagationsInteractions
In string theory, both propagation and interaction of particlesare explained by one set of equations.
This looks nice on paper, but in practice it involvessuper-symmetry. . .
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
No more infinities
No divergences in string theory because:
there is one type of world-sheet, the oriented Riemann surfacehas a unique world-sheet topologythe topology is UV finite, with one Feynman diagram
So it is in a better position than QFT
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
No more infinities
No divergences in string theory because:
there is one type of world-sheet, the oriented Riemann surface
has a unique world-sheet topologythe topology is UV finite, with one Feynman diagram
So it is in a better position than QFT
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
No more infinities
No divergences in string theory because:
there is one type of world-sheet, the oriented Riemann surfacehas a unique world-sheet topology
the topology is UV finite, with one Feynman diagram
So it is in a better position than QFT
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
No more infinities
No divergences in string theory because:
there is one type of world-sheet, the oriented Riemann surfacehas a unique world-sheet topologythe topology is UV finite, with one Feynman diagram
So it is in a better position than QFT
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
No more infinities
No divergences in string theory because:
there is one type of world-sheet, the oriented Riemann surfacehas a unique world-sheet topologythe topology is UV finite, with one Feynman diagram
So it is in a better position than QFT
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Super-symmetry
String theory in its current formulation needs supersymmetrybecause
A fermionic (and bosonic) field on strings needs an extra field,the super-symmetric field (SUSY)
Bosonic string theory does not need SUSY, but they areincomplete and inconsistent
To get the Yang-Mills fields and symmetries a very intricatetopology of spacetime is needed
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Super-symmetry
String theory in its current formulation needs supersymmetrybecause
A fermionic (and bosonic) field on strings needs an extra field,the super-symmetric field (SUSY)
Bosonic string theory does not need SUSY, but they areincomplete and inconsistent
To get the Yang-Mills fields and symmetries a very intricatetopology of spacetime is needed
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Super-symmetry
String theory in its current formulation needs supersymmetrybecause
A fermionic (and bosonic) field on strings needs an extra field,the super-symmetric field (SUSY)
Bosonic string theory does not need SUSY, but they areincomplete and inconsistent
To get the Yang-Mills fields and symmetries a very intricatetopology of spacetime is needed
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Super-symmetry
String theory in its current formulation needs supersymmetrybecause
A fermionic (and bosonic) field on strings needs an extra field,the super-symmetric field (SUSY)
Bosonic string theory does not need SUSY, but they areincomplete and inconsistent
To get the Yang-Mills fields and symmetries a very intricatetopology of spacetime is needed
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Super-symmetry
String theory in its current formulation needs supersymmetrybecause
A fermionic (and bosonic) field on strings needs an extra field,the super-symmetric field (SUSY)
Bosonic string theory does not need SUSY, but they areincomplete and inconsistent
To get the Yang-Mills fields and symmetries a very intricatetopology of spacetime is needed
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
History: the humble and shady origins of string theory
Hard to define: there are several family of models in ST
String theory underwent several plastic surgery procedures(“string revolutions”)
Has humble origins:
Originated in the S-matrix formalism (of bygone days)ST was used to correct the hadron modelIt modeled the interaction of two quarks as being carried by astring.The ends of the string were a quark and an antiquarkThree quarks can be composed to build a baryon.
But QCD completely ruled out the original string theory
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
History: the humble and shady origins of string theory
Hard to define: there are several family of models in ST
String theory underwent several plastic surgery procedures(“string revolutions”)
Has humble origins:
Originated in the S-matrix formalism (of bygone days)ST was used to correct the hadron modelIt modeled the interaction of two quarks as being carried by astring.The ends of the string were a quark and an antiquarkThree quarks can be composed to build a baryon.
But QCD completely ruled out the original string theory
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
History: the humble and shady origins of string theory
Hard to define: there are several family of models in ST
String theory underwent several plastic surgery procedures(“string revolutions”)
Has humble origins:
Originated in the S-matrix formalism (of bygone days)ST was used to correct the hadron modelIt modeled the interaction of two quarks as being carried by astring.The ends of the string were a quark and an antiquarkThree quarks can be composed to build a baryon.
But QCD completely ruled out the original string theory
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
History: the humble and shady origins of string theory
Hard to define: there are several family of models in ST
String theory underwent several plastic surgery procedures(“string revolutions”)
Has humble origins:
Originated in the S-matrix formalism (of bygone days)ST was used to correct the hadron modelIt modeled the interaction of two quarks as being carried by astring.The ends of the string were a quark and an antiquarkThree quarks can be composed to build a baryon.
But QCD completely ruled out the original string theory
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
History: the humble and shady origins of string theory
Hard to define: there are several family of models in ST
String theory underwent several plastic surgery procedures(“string revolutions”)
Has humble origins:
Originated in the S-matrix formalism (of bygone days)
ST was used to correct the hadron modelIt modeled the interaction of two quarks as being carried by astring.The ends of the string were a quark and an antiquarkThree quarks can be composed to build a baryon.
But QCD completely ruled out the original string theory
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
History: the humble and shady origins of string theory
Hard to define: there are several family of models in ST
String theory underwent several plastic surgery procedures(“string revolutions”)
Has humble origins:
Originated in the S-matrix formalism (of bygone days)ST was used to correct the hadron model
It modeled the interaction of two quarks as being carried by astring.The ends of the string were a quark and an antiquarkThree quarks can be composed to build a baryon.
But QCD completely ruled out the original string theory
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
History: the humble and shady origins of string theory
Hard to define: there are several family of models in ST
String theory underwent several plastic surgery procedures(“string revolutions”)
Has humble origins:
Originated in the S-matrix formalism (of bygone days)ST was used to correct the hadron modelIt modeled the interaction of two quarks as being carried by astring.
The ends of the string were a quark and an antiquarkThree quarks can be composed to build a baryon.
But QCD completely ruled out the original string theory
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
History: the humble and shady origins of string theory
Hard to define: there are several family of models in ST
String theory underwent several plastic surgery procedures(“string revolutions”)
Has humble origins:
Originated in the S-matrix formalism (of bygone days)ST was used to correct the hadron modelIt modeled the interaction of two quarks as being carried by astring.The ends of the string were a quark and an antiquark
Three quarks can be composed to build a baryon.
But QCD completely ruled out the original string theory
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
History: the humble and shady origins of string theory
Hard to define: there are several family of models in ST
String theory underwent several plastic surgery procedures(“string revolutions”)
Has humble origins:
Originated in the S-matrix formalism (of bygone days)ST was used to correct the hadron modelIt modeled the interaction of two quarks as being carried by astring.The ends of the string were a quark and an antiquarkThree quarks can be composed to build a baryon.
But QCD completely ruled out the original string theory
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
History: the humble and shady origins of string theory
Hard to define: there are several family of models in ST
String theory underwent several plastic surgery procedures(“string revolutions”)
Has humble origins:
Originated in the S-matrix formalism (of bygone days)ST was used to correct the hadron modelIt modeled the interaction of two quarks as being carried by astring.The ends of the string were a quark and an antiquarkThree quarks can be composed to build a baryon.
But QCD completely ruled out the original string theory
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
ST is a QFT program
It does not solve the philosophical problems of QM or QFT
It gives up the principles of GR
It adds stringy problems on the top of the existing problems(Weingard)
Are we really, really, really ready to give up relativity for shortdistances?
Some philosophers would be happy to entertain this possibility:Albert, Maudlin, i.a.Physicists are less enthusiasticThis is sometimes advertised as a virtue of ST.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
ST is a QFT program
It does not solve the philosophical problems of QM or QFT
It gives up the principles of GR
It adds stringy problems on the top of the existing problems(Weingard)
Are we really, really, really ready to give up relativity for shortdistances?
Some philosophers would be happy to entertain this possibility:Albert, Maudlin, i.a.Physicists are less enthusiasticThis is sometimes advertised as a virtue of ST.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
ST is a QFT program
It does not solve the philosophical problems of QM or QFT
It gives up the principles of GR
It adds stringy problems on the top of the existing problems(Weingard)
Are we really, really, really ready to give up relativity for shortdistances?
Some philosophers would be happy to entertain this possibility:Albert, Maudlin, i.a.Physicists are less enthusiasticThis is sometimes advertised as a virtue of ST.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
ST is a QFT program
It does not solve the philosophical problems of QM or QFT
It gives up the principles of GR
It adds stringy problems on the top of the existing problems(Weingard)
Are we really, really, really ready to give up relativity for shortdistances?
Some philosophers would be happy to entertain this possibility:Albert, Maudlin, i.a.Physicists are less enthusiasticThis is sometimes advertised as a virtue of ST.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
ST is a QFT program
It does not solve the philosophical problems of QM or QFT
It gives up the principles of GR
It adds stringy problems on the top of the existing problems(Weingard)
Are we really, really, really ready to give up relativity for shortdistances?
Some philosophers would be happy to entertain this possibility:Albert, Maudlin, i.a.Physicists are less enthusiasticThis is sometimes advertised as a virtue of ST.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
ST is a QFT program
It does not solve the philosophical problems of QM or QFT
It gives up the principles of GR
It adds stringy problems on the top of the existing problems(Weingard)
Are we really, really, really ready to give up relativity for shortdistances?
Some philosophers would be happy to entertain this possibility:Albert, Maudlin, i.a.
Physicists are less enthusiasticThis is sometimes advertised as a virtue of ST.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
ST is a QFT program
It does not solve the philosophical problems of QM or QFT
It gives up the principles of GR
It adds stringy problems on the top of the existing problems(Weingard)
Are we really, really, really ready to give up relativity for shortdistances?
Some philosophers would be happy to entertain this possibility:Albert, Maudlin, i.a.Physicists are less enthusiastic
This is sometimes advertised as a virtue of ST.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
ST is a QFT program
It does not solve the philosophical problems of QM or QFT
It gives up the principles of GR
It adds stringy problems on the top of the existing problems(Weingard)
Are we really, really, really ready to give up relativity for shortdistances?
Some philosophers would be happy to entertain this possibility:Albert, Maudlin, i.a.Physicists are less enthusiasticThis is sometimes advertised as a virtue of ST.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
ST is a QFT program
It does not solve the philosophical problems of QM or QFT
It gives up the principles of GR
It adds stringy problems on the top of the existing problems(Weingard)
Are we really, really, really ready to give up relativity for shortdistances?
Some philosophers would be happy to entertain this possibility:Albert, Maudlin, i.a.Physicists are less enthusiasticThis is sometimes advertised as a virtue of ST.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Is ST a specific QG?
All other QG programs integrate general relativity withquantum mechanics simpliciter
String theory is a grand unification model: GR raise from aQFT formalism (a Standard Model formalism)
Other QG integrate QM into GR
Hence ST is not strictly speaking a QG program because it iscentred on the Standard Model, on QFT in fact (Rickles,2010)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Is ST a specific QG?
All other QG programs integrate general relativity withquantum mechanics simpliciter
String theory is a grand unification model: GR raise from aQFT formalism (a Standard Model formalism)
Other QG integrate QM into GR
Hence ST is not strictly speaking a QG program because it iscentred on the Standard Model, on QFT in fact (Rickles,2010)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Is ST a specific QG?
All other QG programs integrate general relativity withquantum mechanics simpliciter
String theory is a grand unification model: GR raise from aQFT formalism (a Standard Model formalism)
Other QG integrate QM into GR
Hence ST is not strictly speaking a QG program because it iscentred on the Standard Model, on QFT in fact (Rickles,2010)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Is ST a specific QG?
All other QG programs integrate general relativity withquantum mechanics simpliciter
String theory is a grand unification model: GR raise from aQFT formalism (a Standard Model formalism)
Other QG integrate QM into GR
Hence ST is not strictly speaking a QG program because it iscentred on the Standard Model, on QFT in fact (Rickles,2010)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Is ST a specific QG?
All other QG programs integrate general relativity withquantum mechanics simpliciter
String theory is a grand unification model: GR raise from aQFT formalism (a Standard Model formalism)
Other QG integrate QM into GR
Hence ST is not strictly speaking a QG program because it iscentred on the Standard Model, on QFT in fact (Rickles,2010)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Why “super” is not good
There is Super-Symmetry in the Standard Model (SSSM):most likely, false
Super-gravity (SUGRAV): most likely false
Superstring theory uses SUSY in a different manner. Not as aconjunction of SSM and SUGRAV
it employs the mathematical apparatus of them
Philosophical question: can we combine/unify two falsemodels into a model closer to truth than the unified models?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Why “super” is not good
There is Super-Symmetry in the Standard Model (SSSM):most likely, false
Super-gravity (SUGRAV): most likely false
Superstring theory uses SUSY in a different manner. Not as aconjunction of SSM and SUGRAV
it employs the mathematical apparatus of them
Philosophical question: can we combine/unify two falsemodels into a model closer to truth than the unified models?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Why “super” is not good
There is Super-Symmetry in the Standard Model (SSSM):most likely, false
Super-gravity (SUGRAV): most likely false
Superstring theory uses SUSY in a different manner. Not as aconjunction of SSM and SUGRAV
it employs the mathematical apparatus of them
Philosophical question: can we combine/unify two falsemodels into a model closer to truth than the unified models?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Why “super” is not good
There is Super-Symmetry in the Standard Model (SSSM):most likely, false
Super-gravity (SUGRAV): most likely false
Superstring theory uses SUSY in a different manner. Not as aconjunction of SSM and SUGRAV
it employs the mathematical apparatus of them
Philosophical question: can we combine/unify two falsemodels into a model closer to truth than the unified models?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Why “super” is not good
There is Super-Symmetry in the Standard Model (SSSM):most likely, false
Super-gravity (SUGRAV): most likely false
Superstring theory uses SUSY in a different manner. Not as aconjunction of SSM and SUGRAV
it employs the mathematical apparatus of them
Philosophical question: can we combine/unify two falsemodels into a model closer to truth than the unified models?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Why “super” is not good
There is Super-Symmetry in the Standard Model (SSSM):most likely, false
Super-gravity (SUGRAV): most likely false
Superstring theory uses SUSY in a different manner. Not as aconjunction of SSM and SUGRAV
it employs the mathematical apparatus of them
Philosophical question: can we combine/unify two falsemodels into a model closer to truth than the unified models?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Superstring Theory
Green and Schwarz (1984)
No tachyons
Finite and consistent
Symmetry group: SO(32)
D=10
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Superstring Theory
Green and Schwarz (1984)
No tachyons
Finite and consistent
Symmetry group: SO(32)
D=10
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Superstring Theory
Green and Schwarz (1984)
No tachyons
Finite and consistent
Symmetry group: SO(32)
D=10
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Superstring Theory
Green and Schwarz (1984)
No tachyons
Finite and consistent
Symmetry group: SO(32)
D=10
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Superstring Theory
Green and Schwarz (1984)
No tachyons
Finite and consistent
Symmetry group: SO(32)
D=10
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Superstring Theory
Green and Schwarz (1984)
No tachyons
Finite and consistent
Symmetry group: SO(32)
D=10
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Five types of string theories
Bosonic string theory: D=26, with no symmetry, in whichstrings vibrate only in the bosonic mode.
Type I String Theory: fermions and bosons: D=10 andsupersymmetry is present.
Type II-A: Supersymmetry is present and strings are open andclosed. D-branes are also subspaces on which strings areattached. Fermions are not chiral.
Type II-B: same as Type II-A, but includes chirality.
Heterotic ST: Only closed strings. D=10 on left movers, andD=26 on right movers
Several types of heterotic string theories exist
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Five types of string theories
Bosonic string theory: D=26, with no symmetry, in whichstrings vibrate only in the bosonic mode.
Type I String Theory: fermions and bosons: D=10 andsupersymmetry is present.
Type II-A: Supersymmetry is present and strings are open andclosed. D-branes are also subspaces on which strings areattached. Fermions are not chiral.
Type II-B: same as Type II-A, but includes chirality.
Heterotic ST: Only closed strings. D=10 on left movers, andD=26 on right movers
Several types of heterotic string theories exist
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Five types of string theories
Bosonic string theory: D=26, with no symmetry, in whichstrings vibrate only in the bosonic mode.
Type I String Theory: fermions and bosons: D=10 andsupersymmetry is present.
Type II-A: Supersymmetry is present and strings are open andclosed. D-branes are also subspaces on which strings areattached. Fermions are not chiral.
Type II-B: same as Type II-A, but includes chirality.
Heterotic ST: Only closed strings. D=10 on left movers, andD=26 on right movers
Several types of heterotic string theories exist
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Five types of string theories
Bosonic string theory: D=26, with no symmetry, in whichstrings vibrate only in the bosonic mode.
Type I String Theory: fermions and bosons: D=10 andsupersymmetry is present.
Type II-A: Supersymmetry is present and strings are open andclosed. D-branes are also subspaces on which strings areattached. Fermions are not chiral.
Type II-B: same as Type II-A, but includes chirality.
Heterotic ST: Only closed strings. D=10 on left movers, andD=26 on right movers
Several types of heterotic string theories exist
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Five types of string theories
Bosonic string theory: D=26, with no symmetry, in whichstrings vibrate only in the bosonic mode.
Type I String Theory: fermions and bosons: D=10 andsupersymmetry is present.
Type II-A: Supersymmetry is present and strings are open andclosed. D-branes are also subspaces on which strings areattached. Fermions are not chiral.
Type II-B: same as Type II-A, but includes chirality.
Heterotic ST: Only closed strings. D=10 on left movers, andD=26 on right movers
Several types of heterotic string theories exist
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Five types of string theories
Bosonic string theory: D=26, with no symmetry, in whichstrings vibrate only in the bosonic mode.
Type I String Theory: fermions and bosons: D=10 andsupersymmetry is present.
Type II-A: Supersymmetry is present and strings are open andclosed. D-branes are also subspaces on which strings areattached. Fermions are not chiral.
Type II-B: same as Type II-A, but includes chirality.
Heterotic ST: Only closed strings. D=10 on left movers, andD=26 on right movers
Several types of heterotic string theories exist
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Five types of string theories
Bosonic string theory: D=26, with no symmetry, in whichstrings vibrate only in the bosonic mode.
Type I String Theory: fermions and bosons: D=10 andsupersymmetry is present.
Type II-A: Supersymmetry is present and strings are open andclosed. D-branes are also subspaces on which strings areattached. Fermions are not chiral.
Type II-B: same as Type II-A, but includes chirality.
Heterotic ST: Only closed strings. D=10 on left movers, andD=26 on right movers
Several types of heterotic string theories exist
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
String Theory and spacetime
Unlike other QG programs, string theory’s structure ofspacetime is more complicated:
Dimensionality D>4Exotic topologiesCompactificationThe dynamics of spacetime is codified by the “dilaton” field
The GR physicists would insist:
So what? What determines the structure of the convolutedspacetime?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
String Theory and spacetime
Unlike other QG programs, string theory’s structure ofspacetime is more complicated:
Dimensionality D>4Exotic topologiesCompactificationThe dynamics of spacetime is codified by the “dilaton” field
The GR physicists would insist:
So what? What determines the structure of the convolutedspacetime?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
String Theory and spacetime
Unlike other QG programs, string theory’s structure ofspacetime is more complicated:
Dimensionality D>4
Exotic topologiesCompactificationThe dynamics of spacetime is codified by the “dilaton” field
The GR physicists would insist:
So what? What determines the structure of the convolutedspacetime?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
String Theory and spacetime
Unlike other QG programs, string theory’s structure ofspacetime is more complicated:
Dimensionality D>4Exotic topologies
CompactificationThe dynamics of spacetime is codified by the “dilaton” field
The GR physicists would insist:
So what? What determines the structure of the convolutedspacetime?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
String Theory and spacetime
Unlike other QG programs, string theory’s structure ofspacetime is more complicated:
Dimensionality D>4Exotic topologiesCompactification
The dynamics of spacetime is codified by the “dilaton” field
The GR physicists would insist:
So what? What determines the structure of the convolutedspacetime?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
String Theory and spacetime
Unlike other QG programs, string theory’s structure ofspacetime is more complicated:
Dimensionality D>4Exotic topologiesCompactificationThe dynamics of spacetime is codified by the “dilaton” field
The GR physicists would insist:
So what? What determines the structure of the convolutedspacetime?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
String Theory and spacetime
Unlike other QG programs, string theory’s structure ofspacetime is more complicated:
Dimensionality D>4Exotic topologiesCompactificationThe dynamics of spacetime is codified by the “dilaton” field
The GR physicists would insist:
So what? What determines the structure of the convolutedspacetime?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
String Theory and spacetime
Unlike other QG programs, string theory’s structure ofspacetime is more complicated:
Dimensionality D>4Exotic topologiesCompactificationThe dynamics of spacetime is codified by the “dilaton” field
The GR physicists would insist:
So what? What determines the structure of the convolutedspacetime?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
BACKGROUND in ST
There is a way to answer BACKGROUND:
ST can be formulated in curved spacetime ((?, ch. 3))
So replace η with G
Here we have a perturbation theory
Here we go again!
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
BACKGROUND in ST
There is a way to answer BACKGROUND:
ST can be formulated in curved spacetime ((?, ch. 3))
So replace η with G
Here we have a perturbation theory
Here we go again!
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
BACKGROUND in ST
There is a way to answer BACKGROUND:
ST can be formulated in curved spacetime ((?, ch. 3))
So replace η with G
Here we have a perturbation theory
Here we go again!
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
BACKGROUND in ST
There is a way to answer BACKGROUND:
ST can be formulated in curved spacetime ((?, ch. 3))
So replace η with G
Here we have a perturbation theory
Here we go again!
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
BACKGROUND in ST
There is a way to answer BACKGROUND:
ST can be formulated in curved spacetime ((?, ch. 3))
So replace η with G
Here we have a perturbation theory
Here we go again!
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
BACKGROUND in ST
There is a way to answer BACKGROUND:
ST can be formulated in curved spacetime ((?, ch. 3))
So replace η with G
Here we have a perturbation theory
Here we go again!
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The naive solution to BACKGROUND
Curved spacetime is a formed by a collection of gravitons
Gravitons are states of strings
So the background spacetime is in itself dynamical.
Do string theorists beg the question?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The naive solution to BACKGROUND
Curved spacetime is a formed by a collection of gravitons
Gravitons are states of strings
So the background spacetime is in itself dynamical.
Do string theorists beg the question?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The naive solution to BACKGROUND
Curved spacetime is a formed by a collection of gravitons
Gravitons are states of strings
So the background spacetime is in itself dynamical.
Do string theorists beg the question?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The naive solution to BACKGROUND
Curved spacetime is a formed by a collection of gravitons
Gravitons are states of strings
So the background spacetime is in itself dynamical.
Do string theorists beg the question?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The naive solution to BACKGROUND
Curved spacetime is a formed by a collection of gravitons
Gravitons are states of strings
So the background spacetime is in itself dynamical.
Do string theorists beg the question?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Background spacetime as a interaction among strings
Different G, B and Φ fields give different backgrounds
But Φ0 = λ is the coupling constant among strings.
The coupling constant is determined by the dynamics.
In ST fields can propagate only in specific backgroundspacetimes, strongly constrained.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Background spacetime as a interaction among strings
Different G, B and Φ fields give different backgrounds
But Φ0 = λ is the coupling constant among strings.
The coupling constant is determined by the dynamics.
In ST fields can propagate only in specific backgroundspacetimes, strongly constrained.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Background spacetime as a interaction among strings
Different G, B and Φ fields give different backgrounds
But Φ0 = λ is the coupling constant among strings.
The coupling constant is determined by the dynamics.
In ST fields can propagate only in specific backgroundspacetimes, strongly constrained.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Background spacetime as a interaction among strings
Different G, B and Φ fields give different backgrounds
But Φ0 = λ is the coupling constant among strings.
The coupling constant is determined by the dynamics.
In ST fields can propagate only in specific backgroundspacetimes, strongly constrained.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Background spacetime as a interaction among strings
Different G, B and Φ fields give different backgrounds
But Φ0 = λ is the coupling constant among strings.
The coupling constant is determined by the dynamics.
In ST fields can propagate only in specific backgroundspacetimes, strongly constrained.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
ST and Lorentz invariance
“The basic physical consistency conditions are few innumber. We require Lorentz invariance, and we requirethat quantum mechanical probabilities be positive andconserved—to date, nothing in string theory seems torequire that the standard quantum mechanical frameworkbe modified, though it would be interesting to learnotherwise” (Polchinski 1998, 1:116).
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
ST and Lorentz invariance
“The basic physical consistency conditions are few innumber. We require Lorentz invariance, and we requirethat quantum mechanical probabilities be positive andconserved—to date, nothing in string theory seems torequire that the standard quantum mechanical frameworkbe modified, though it would be interesting to learnotherwise” (Polchinski 1998, 1:116).
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
ST as a conservative program
Tasks for a bosonic ST
Quantize a classical entity, the stringTry to recover Lorentz invarianceEliminate tachyonic modes and ghost fields
Problems:
Assumes a classical concept of spacetime manifold, as doesQFTIt has various techniques of quantization (conformal, BRST,ligh-cone) each ascertaining to different resultspiggybacks on classical mechanics and special relativity
Is it a good candidate for a TOE or a fundamental theory if itbypasses GR?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
ST as a conservative program
Tasks for a bosonic ST
Quantize a classical entity, the stringTry to recover Lorentz invarianceEliminate tachyonic modes and ghost fields
Problems:
Assumes a classical concept of spacetime manifold, as doesQFTIt has various techniques of quantization (conformal, BRST,ligh-cone) each ascertaining to different resultspiggybacks on classical mechanics and special relativity
Is it a good candidate for a TOE or a fundamental theory if itbypasses GR?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
ST as a conservative program
Tasks for a bosonic ST
Quantize a classical entity, the string
Try to recover Lorentz invarianceEliminate tachyonic modes and ghost fields
Problems:
Assumes a classical concept of spacetime manifold, as doesQFTIt has various techniques of quantization (conformal, BRST,ligh-cone) each ascertaining to different resultspiggybacks on classical mechanics and special relativity
Is it a good candidate for a TOE or a fundamental theory if itbypasses GR?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
ST as a conservative program
Tasks for a bosonic ST
Quantize a classical entity, the stringTry to recover Lorentz invariance
Eliminate tachyonic modes and ghost fields
Problems:
Assumes a classical concept of spacetime manifold, as doesQFTIt has various techniques of quantization (conformal, BRST,ligh-cone) each ascertaining to different resultspiggybacks on classical mechanics and special relativity
Is it a good candidate for a TOE or a fundamental theory if itbypasses GR?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
ST as a conservative program
Tasks for a bosonic ST
Quantize a classical entity, the stringTry to recover Lorentz invarianceEliminate tachyonic modes and ghost fields
Problems:
Assumes a classical concept of spacetime manifold, as doesQFTIt has various techniques of quantization (conformal, BRST,ligh-cone) each ascertaining to different resultspiggybacks on classical mechanics and special relativity
Is it a good candidate for a TOE or a fundamental theory if itbypasses GR?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
ST as a conservative program
Tasks for a bosonic ST
Quantize a classical entity, the stringTry to recover Lorentz invarianceEliminate tachyonic modes and ghost fields
Problems:
Assumes a classical concept of spacetime manifold, as doesQFTIt has various techniques of quantization (conformal, BRST,ligh-cone) each ascertaining to different resultspiggybacks on classical mechanics and special relativity
Is it a good candidate for a TOE or a fundamental theory if itbypasses GR?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
ST as a conservative program
Tasks for a bosonic ST
Quantize a classical entity, the stringTry to recover Lorentz invarianceEliminate tachyonic modes and ghost fields
Problems:
Assumes a classical concept of spacetime manifold, as doesQFT
It has various techniques of quantization (conformal, BRST,ligh-cone) each ascertaining to different resultspiggybacks on classical mechanics and special relativity
Is it a good candidate for a TOE or a fundamental theory if itbypasses GR?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
ST as a conservative program
Tasks for a bosonic ST
Quantize a classical entity, the stringTry to recover Lorentz invarianceEliminate tachyonic modes and ghost fields
Problems:
Assumes a classical concept of spacetime manifold, as doesQFTIt has various techniques of quantization (conformal, BRST,ligh-cone) each ascertaining to different results
piggybacks on classical mechanics and special relativity
Is it a good candidate for a TOE or a fundamental theory if itbypasses GR?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
ST as a conservative program
Tasks for a bosonic ST
Quantize a classical entity, the stringTry to recover Lorentz invarianceEliminate tachyonic modes and ghost fields
Problems:
Assumes a classical concept of spacetime manifold, as doesQFTIt has various techniques of quantization (conformal, BRST,ligh-cone) each ascertaining to different resultspiggybacks on classical mechanics and special relativity
Is it a good candidate for a TOE or a fundamental theory if itbypasses GR?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
ST as a conservative program
Tasks for a bosonic ST
Quantize a classical entity, the stringTry to recover Lorentz invarianceEliminate tachyonic modes and ghost fields
Problems:
Assumes a classical concept of spacetime manifold, as doesQFTIt has various techniques of quantization (conformal, BRST,ligh-cone) each ascertaining to different resultspiggybacks on classical mechanics and special relativity
Is it a good candidate for a TOE or a fundamental theory if itbypasses GR?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The toy model
Take a string (open or closed)Write down its action (roughly, it is the area of the stringworldsheet)
Nambu Goto SNG
Polyakov:
SNB−σ = SP = −T
2
∫d2σ√−hhαβ∂αXµ∂αX ν
Look at the symmetries of the action
Poincare group: Lorentz and translations (global)Reparametrization group (local)Weyl scaling (local)
Let it vibrate in a (flat?) spacetime with D dimensions
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The toy model
Take a string (open or closed)
Write down its action (roughly, it is the area of the stringworldsheet)
Nambu Goto SNG
Polyakov:
SNB−σ = SP = −T
2
∫d2σ√−hhαβ∂αXµ∂αX ν
Look at the symmetries of the action
Poincare group: Lorentz and translations (global)Reparametrization group (local)Weyl scaling (local)
Let it vibrate in a (flat?) spacetime with D dimensions
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The toy model
Take a string (open or closed)Write down its action (roughly, it is the area of the stringworldsheet)
Nambu Goto SNG
Polyakov:
SNB−σ = SP = −T
2
∫d2σ√−hhαβ∂αXµ∂αX ν
Look at the symmetries of the action
Poincare group: Lorentz and translations (global)Reparametrization group (local)Weyl scaling (local)
Let it vibrate in a (flat?) spacetime with D dimensions
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The toy model
Take a string (open or closed)Write down its action (roughly, it is the area of the stringworldsheet)
Nambu Goto SNG
Polyakov:
SNB−σ = SP = −T
2
∫d2σ√−hhαβ∂αXµ∂αX ν
Look at the symmetries of the action
Poincare group: Lorentz and translations (global)Reparametrization group (local)Weyl scaling (local)
Let it vibrate in a (flat?) spacetime with D dimensions
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The toy model
Take a string (open or closed)Write down its action (roughly, it is the area of the stringworldsheet)
Nambu Goto SNG
Polyakov:
SNB−σ = SP = −T
2
∫d2σ√−hhαβ∂αXµ∂αX ν
Look at the symmetries of the action
Poincare group: Lorentz and translations (global)Reparametrization group (local)Weyl scaling (local)
Let it vibrate in a (flat?) spacetime with D dimensions
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The toy model
Take a string (open or closed)Write down its action (roughly, it is the area of the stringworldsheet)
Nambu Goto SNG
Polyakov:
SNB−σ = SP = −T
2
∫d2σ√−hhαβ∂αXµ∂αX ν
Look at the symmetries of the action
Poincare group: Lorentz and translations (global)Reparametrization group (local)Weyl scaling (local)
Let it vibrate in a (flat?) spacetime with D dimensions
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The toy model
Take a string (open or closed)Write down its action (roughly, it is the area of the stringworldsheet)
Nambu Goto SNG
Polyakov:
SNB−σ = SP = −T
2
∫d2σ√−hhαβ∂αXµ∂αX ν
Look at the symmetries of the actionPoincare group: Lorentz and translations (global)
Reparametrization group (local)Weyl scaling (local)
Let it vibrate in a (flat?) spacetime with D dimensions
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The toy model
Take a string (open or closed)Write down its action (roughly, it is the area of the stringworldsheet)
Nambu Goto SNG
Polyakov:
SNB−σ = SP = −T
2
∫d2σ√−hhαβ∂αXµ∂αX ν
Look at the symmetries of the actionPoincare group: Lorentz and translations (global)Reparametrization group (local)
Weyl scaling (local)
Let it vibrate in a (flat?) spacetime with D dimensions
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The toy model
Take a string (open or closed)Write down its action (roughly, it is the area of the stringworldsheet)
Nambu Goto SNG
Polyakov:
SNB−σ = SP = −T
2
∫d2σ√−hhαβ∂αXµ∂αX ν
Look at the symmetries of the actionPoincare group: Lorentz and translations (global)Reparametrization group (local)Weyl scaling (local)
Let it vibrate in a (flat?) spacetime with D dimensions
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The toy model
Take a string (open or closed)Write down its action (roughly, it is the area of the stringworldsheet)
Nambu Goto SNG
Polyakov:
SNB−σ = SP = −T
2
∫d2σ√−hhαβ∂αXµ∂αX ν
Look at the symmetries of the actionPoincare group: Lorentz and translations (global)Reparametrization group (local)Weyl scaling (local)
Let it vibrate in a (flat?) spacetime with D dimensions
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The toy model quantized
Quantize the string action (first quantization):
Several procedures are available:
CovariantBRSTLight cone
Impose canonical commutation relations
Look at its spectrum and what it contains
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The toy model quantized
Quantize the string action (first quantization):
Several procedures are available:
CovariantBRSTLight cone
Impose canonical commutation relations
Look at its spectrum and what it contains
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The toy model quantized
Quantize the string action (first quantization):
Several procedures are available:
CovariantBRSTLight cone
Impose canonical commutation relations
Look at its spectrum and what it contains
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The toy model quantized
Quantize the string action (first quantization):
Several procedures are available:
Covariant
BRSTLight cone
Impose canonical commutation relations
Look at its spectrum and what it contains
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The toy model quantized
Quantize the string action (first quantization):
Several procedures are available:
CovariantBRST
Light cone
Impose canonical commutation relations
Look at its spectrum and what it contains
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The toy model quantized
Quantize the string action (first quantization):
Several procedures are available:
CovariantBRSTLight cone
Impose canonical commutation relations
Look at its spectrum and what it contains
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The toy model quantized
Quantize the string action (first quantization):
Several procedures are available:
CovariantBRSTLight cone
Impose canonical commutation relations
Look at its spectrum and what it contains
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The toy model quantized
Quantize the string action (first quantization):
Several procedures are available:
CovariantBRSTLight cone
Impose canonical commutation relations
Look at its spectrum and what it contains
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The closed string spectrum
XµL (τ, σ) = xµ
2 +`2S2 pµ(τ + σ) + i `S√
2
∑k 6=0
αµkk e−ik(τ+σ)
XµR (τ, σ) = xµ
2 +`2S2 pµ(τ − σ) + i `S√
2
∑k 6=0
αµkk e−ik(τ−σ)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The closed string spectrum
XµL (τ, σ) = xµ
2 +`2S2 pµ(τ + σ) + i `S√
2
∑k 6=0
αµkk e−ik(τ+σ)
XµR (τ, σ) = xµ
2 +`2S2 pµ(τ − σ) + i `S√
2
∑k 6=0
αµkk e−ik(τ−σ)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Some constraints on the toy model
The spectra (for both open and closed strings) look “ugly”.It has:
1 Tachyonic states, because of the
M2 |0〉 = − 1
α′|0〉
2 Spin-2 bosonic states3 Negative norm states
Which of them needs to stay, which goes?It depends:If string theory is a model of hadrons, all need to go.And that was not possible.3. can be stripped out.1. cannot be eliminated and2. is a real surprise, it is the signature of gravitation
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Some constraints on the toy model
The spectra (for both open and closed strings) look “ugly”.
It has:
1 Tachyonic states, because of the
M2 |0〉 = − 1
α′|0〉
2 Spin-2 bosonic states3 Negative norm states
Which of them needs to stay, which goes?It depends:If string theory is a model of hadrons, all need to go.And that was not possible.3. can be stripped out.1. cannot be eliminated and2. is a real surprise, it is the signature of gravitation
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Some constraints on the toy model
The spectra (for both open and closed strings) look “ugly”.It has:
1 Tachyonic states, because of the
M2 |0〉 = − 1
α′|0〉
2 Spin-2 bosonic states3 Negative norm states
Which of them needs to stay, which goes?It depends:If string theory is a model of hadrons, all need to go.And that was not possible.3. can be stripped out.1. cannot be eliminated and2. is a real surprise, it is the signature of gravitation
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Some constraints on the toy model
The spectra (for both open and closed strings) look “ugly”.It has:
1 Tachyonic states, because of the
M2 |0〉 = − 1
α′|0〉
2 Spin-2 bosonic states3 Negative norm states
Which of them needs to stay, which goes?It depends:If string theory is a model of hadrons, all need to go.And that was not possible.3. can be stripped out.1. cannot be eliminated and2. is a real surprise, it is the signature of gravitation
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Some constraints on the toy model
The spectra (for both open and closed strings) look “ugly”.It has:
1 Tachyonic states, because of the
M2 |0〉 = − 1
α′|0〉
2 Spin-2 bosonic states
3 Negative norm states
Which of them needs to stay, which goes?It depends:If string theory is a model of hadrons, all need to go.And that was not possible.3. can be stripped out.1. cannot be eliminated and2. is a real surprise, it is the signature of gravitation
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Some constraints on the toy model
The spectra (for both open and closed strings) look “ugly”.It has:
1 Tachyonic states, because of the
M2 |0〉 = − 1
α′|0〉
2 Spin-2 bosonic states3 Negative norm states
Which of them needs to stay, which goes?It depends:If string theory is a model of hadrons, all need to go.And that was not possible.3. can be stripped out.1. cannot be eliminated and2. is a real surprise, it is the signature of gravitation
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Some constraints on the toy model
The spectra (for both open and closed strings) look “ugly”.It has:
1 Tachyonic states, because of the
M2 |0〉 = − 1
α′|0〉
2 Spin-2 bosonic states3 Negative norm states
Which of them needs to stay, which goes?
It depends:If string theory is a model of hadrons, all need to go.And that was not possible.3. can be stripped out.1. cannot be eliminated and2. is a real surprise, it is the signature of gravitation
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Some constraints on the toy model
The spectra (for both open and closed strings) look “ugly”.It has:
1 Tachyonic states, because of the
M2 |0〉 = − 1
α′|0〉
2 Spin-2 bosonic states3 Negative norm states
Which of them needs to stay, which goes?It depends:
If string theory is a model of hadrons, all need to go.And that was not possible.3. can be stripped out.1. cannot be eliminated and2. is a real surprise, it is the signature of gravitation
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Some constraints on the toy model
The spectra (for both open and closed strings) look “ugly”.It has:
1 Tachyonic states, because of the
M2 |0〉 = − 1
α′|0〉
2 Spin-2 bosonic states3 Negative norm states
Which of them needs to stay, which goes?It depends:If string theory is a model of hadrons, all need to go.
And that was not possible.3. can be stripped out.1. cannot be eliminated and2. is a real surprise, it is the signature of gravitation
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Some constraints on the toy model
The spectra (for both open and closed strings) look “ugly”.It has:
1 Tachyonic states, because of the
M2 |0〉 = − 1
α′|0〉
2 Spin-2 bosonic states3 Negative norm states
Which of them needs to stay, which goes?It depends:If string theory is a model of hadrons, all need to go.And that was not possible.
3. can be stripped out.1. cannot be eliminated and2. is a real surprise, it is the signature of gravitation
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Some constraints on the toy model
The spectra (for both open and closed strings) look “ugly”.It has:
1 Tachyonic states, because of the
M2 |0〉 = − 1
α′|0〉
2 Spin-2 bosonic states3 Negative norm states
Which of them needs to stay, which goes?It depends:If string theory is a model of hadrons, all need to go.And that was not possible.3. can be stripped out.
1. cannot be eliminated and2. is a real surprise, it is the signature of gravitation
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Some constraints on the toy model
The spectra (for both open and closed strings) look “ugly”.It has:
1 Tachyonic states, because of the
M2 |0〉 = − 1
α′|0〉
2 Spin-2 bosonic states3 Negative norm states
Which of them needs to stay, which goes?It depends:If string theory is a model of hadrons, all need to go.And that was not possible.3. can be stripped out.1. cannot be eliminated and
2. is a real surprise, it is the signature of gravitation
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Some constraints on the toy model
The spectra (for both open and closed strings) look “ugly”.It has:
1 Tachyonic states, because of the
M2 |0〉 = − 1
α′|0〉
2 Spin-2 bosonic states3 Negative norm states
Which of them needs to stay, which goes?It depends:If string theory is a model of hadrons, all need to go.And that was not possible.3. can be stripped out.1. cannot be eliminated and2. is a real surprise, it is the signature of gravitationIoan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Virasoro operators
They are used to eliminate negative norm states
Open :
[Lm, Ln] = (m − n) Ln+n + D12
(m3 −m
)δm+n,0
Closed :
[Lm, Ln] = (m − n) Ln+n + D12
(m3 −m
)δm+n,0[
Lm, Ln
]= (m − n) Ln+n + D
12
(m3 −m
)δm+n,0
I follow here the notation in: ?by working on the expectation values of the Virasorooperators, one can infer:First condition of “physicality”: No ghost fields (withnegative norm states)Applied to the bosonic ST, this renders: D=26, a=1
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Virasoro operators
They are used to eliminate negative norm states
Open :
[Lm, Ln] = (m − n) Ln+n + D12
(m3 −m
)δm+n,0
Closed :
[Lm, Ln] = (m − n) Ln+n + D12
(m3 −m
)δm+n,0[
Lm, Ln
]= (m − n) Ln+n + D
12
(m3 −m
)δm+n,0
I follow here the notation in: ?by working on the expectation values of the Virasorooperators, one can infer:First condition of “physicality”: No ghost fields (withnegative norm states)Applied to the bosonic ST, this renders: D=26, a=1
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Virasoro operators
They are used to eliminate negative norm states
Open :
[Lm, Ln] = (m − n) Ln+n + D12
(m3 −m
)δm+n,0
Closed :
[Lm, Ln] = (m − n) Ln+n + D12
(m3 −m
)δm+n,0[
Lm, Ln
]= (m − n) Ln+n + D
12
(m3 −m
)δm+n,0
I follow here the notation in: ?by working on the expectation values of the Virasorooperators, one can infer:First condition of “physicality”: No ghost fields (withnegative norm states)Applied to the bosonic ST, this renders: D=26, a=1
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Virasoro operators
They are used to eliminate negative norm states
Open :
[Lm, Ln] = (m − n) Ln+n + D12
(m3 −m
)δm+n,0
Closed :
[Lm, Ln] = (m − n) Ln+n + D12
(m3 −m
)δm+n,0[
Lm, Ln
]= (m − n) Ln+n + D
12
(m3 −m
)δm+n,0
I follow here the notation in: ?
by working on the expectation values of the Virasorooperators, one can infer:First condition of “physicality”: No ghost fields (withnegative norm states)Applied to the bosonic ST, this renders: D=26, a=1
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Virasoro operators
They are used to eliminate negative norm states
Open :
[Lm, Ln] = (m − n) Ln+n + D12
(m3 −m
)δm+n,0
Closed :
[Lm, Ln] = (m − n) Ln+n + D12
(m3 −m
)δm+n,0[
Lm, Ln
]= (m − n) Ln+n + D
12
(m3 −m
)δm+n,0
I follow here the notation in: ?by working on the expectation values of the Virasorooperators, one can infer:
First condition of “physicality”: No ghost fields (withnegative norm states)Applied to the bosonic ST, this renders: D=26, a=1
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Virasoro operators
They are used to eliminate negative norm states
Open :
[Lm, Ln] = (m − n) Ln+n + D12
(m3 −m
)δm+n,0
Closed :
[Lm, Ln] = (m − n) Ln+n + D12
(m3 −m
)δm+n,0[
Lm, Ln
]= (m − n) Ln+n + D
12
(m3 −m
)δm+n,0
I follow here the notation in: ?by working on the expectation values of the Virasorooperators, one can infer:First condition of “physicality”: No ghost fields (withnegative norm states)
Applied to the bosonic ST, this renders: D=26, a=1
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Virasoro operators
They are used to eliminate negative norm states
Open :
[Lm, Ln] = (m − n) Ln+n + D12
(m3 −m
)δm+n,0
Closed :
[Lm, Ln] = (m − n) Ln+n + D12
(m3 −m
)δm+n,0[
Lm, Ln
]= (m − n) Ln+n + D
12
(m3 −m
)δm+n,0
I follow here the notation in: ?by working on the expectation values of the Virasorooperators, one can infer:First condition of “physicality”: No ghost fields (withnegative norm states)Applied to the bosonic ST, this renders: D=26, a=1
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Virtues and vices
The original bosonic ST has:
1 Ghost states2 Tachyonic modes3 A massless spin-2 particle
Originally, 3. was a vice of the theory, then it became a virtue(identified with the graviton).
In bosonic string theory, there is no way to eliminate 2.
There are several constraints and symmetries that caneliminate 1. but that entails:
D=26Can’t get rid of 2. and 3.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Virtues and vices
The original bosonic ST has:
1 Ghost states2 Tachyonic modes3 A massless spin-2 particle
Originally, 3. was a vice of the theory, then it became a virtue(identified with the graviton).
In bosonic string theory, there is no way to eliminate 2.
There are several constraints and symmetries that caneliminate 1. but that entails:
D=26Can’t get rid of 2. and 3.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Virtues and vices
The original bosonic ST has:1 Ghost states
2 Tachyonic modes3 A massless spin-2 particle
Originally, 3. was a vice of the theory, then it became a virtue(identified with the graviton).
In bosonic string theory, there is no way to eliminate 2.
There are several constraints and symmetries that caneliminate 1. but that entails:
D=26Can’t get rid of 2. and 3.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Virtues and vices
The original bosonic ST has:1 Ghost states2 Tachyonic modes
3 A massless spin-2 particle
Originally, 3. was a vice of the theory, then it became a virtue(identified with the graviton).
In bosonic string theory, there is no way to eliminate 2.
There are several constraints and symmetries that caneliminate 1. but that entails:
D=26Can’t get rid of 2. and 3.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Virtues and vices
The original bosonic ST has:1 Ghost states2 Tachyonic modes3 A massless spin-2 particle
Originally, 3. was a vice of the theory, then it became a virtue(identified with the graviton).
In bosonic string theory, there is no way to eliminate 2.
There are several constraints and symmetries that caneliminate 1. but that entails:
D=26Can’t get rid of 2. and 3.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Virtues and vices
The original bosonic ST has:1 Ghost states2 Tachyonic modes3 A massless spin-2 particle
Originally, 3. was a vice of the theory, then it became a virtue(identified with the graviton).
In bosonic string theory, there is no way to eliminate 2.
There are several constraints and symmetries that caneliminate 1. but that entails:
D=26Can’t get rid of 2. and 3.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Virtues and vices
The original bosonic ST has:1 Ghost states2 Tachyonic modes3 A massless spin-2 particle
Originally, 3. was a vice of the theory, then it became a virtue(identified with the graviton).
In bosonic string theory, there is no way to eliminate 2.
There are several constraints and symmetries that caneliminate 1. but that entails:
D=26Can’t get rid of 2. and 3.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Virtues and vices
The original bosonic ST has:1 Ghost states2 Tachyonic modes3 A massless spin-2 particle
Originally, 3. was a vice of the theory, then it became a virtue(identified with the graviton).
In bosonic string theory, there is no way to eliminate 2.
There are several constraints and symmetries that caneliminate 1. but that entails:
D=26Can’t get rid of 2. and 3.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Virtues and vices
The original bosonic ST has:1 Ghost states2 Tachyonic modes3 A massless spin-2 particle
Originally, 3. was a vice of the theory, then it became a virtue(identified with the graviton).
In bosonic string theory, there is no way to eliminate 2.
There are several constraints and symmetries that caneliminate 1. but that entails:
D=26
Can’t get rid of 2. and 3.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Virtues and vices
The original bosonic ST has:1 Ghost states2 Tachyonic modes3 A massless spin-2 particle
Originally, 3. was a vice of the theory, then it became a virtue(identified with the graviton).
In bosonic string theory, there is no way to eliminate 2.
There are several constraints and symmetries that caneliminate 1. but that entails:
D=26Can’t get rid of 2. and 3.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
What is X (σ, τ)?
Here is where ST is open to interpretations.
Two interpretations
the GR “friendly” interpretation: X a system of coordinatesGR “unfriendly” interpretation, inspired by QFT: X is abosonic field on the worldsheet
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
What is X (σ, τ)?
Here is where ST is open to interpretations.
Two interpretations
the GR “friendly” interpretation: X a system of coordinatesGR “unfriendly” interpretation, inspired by QFT: X is abosonic field on the worldsheet
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
What is X (σ, τ)?
Here is where ST is open to interpretations.
Two interpretations
the GR “friendly” interpretation: X a system of coordinatesGR “unfriendly” interpretation, inspired by QFT: X is abosonic field on the worldsheet
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
What is X (σ, τ)?
Here is where ST is open to interpretations.
Two interpretations
the GR “friendly” interpretation: X a system of coordinates
GR “unfriendly” interpretation, inspired by QFT: X is abosonic field on the worldsheet
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
What is X (σ, τ)?
Here is where ST is open to interpretations.
Two interpretations
the GR “friendly” interpretation: X a system of coordinatesGR “unfriendly” interpretation, inspired by QFT: X is abosonic field on the worldsheet
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
SUSY on the world-sheet: the RNS model
what is needed to eliminate tachyons and explain more thanthe graviton?Supersymetry (SUSY), inter aliaWhat is SUSY in string theory?Mainly, it is an extra field that can be put:
On the worldsheet (Ramond-Neveu-Schwarz model, RNS)On the real spacetime (Green-Schwarz model, GS)
RNS adds a new term to the SP actionThe new term is a Majorana spinor Ψ with two components(
Ψ−Ψ+
)It is fermionic in natureThe bosonic field X (σ, τ) stays, too.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
SUSY on the world-sheet: the RNS model
what is needed to eliminate tachyons and explain more thanthe graviton?
Supersymetry (SUSY), inter aliaWhat is SUSY in string theory?Mainly, it is an extra field that can be put:
On the worldsheet (Ramond-Neveu-Schwarz model, RNS)On the real spacetime (Green-Schwarz model, GS)
RNS adds a new term to the SP actionThe new term is a Majorana spinor Ψ with two components(
Ψ−Ψ+
)It is fermionic in natureThe bosonic field X (σ, τ) stays, too.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
SUSY on the world-sheet: the RNS model
what is needed to eliminate tachyons and explain more thanthe graviton?Supersymetry (SUSY), inter alia
What is SUSY in string theory?Mainly, it is an extra field that can be put:
On the worldsheet (Ramond-Neveu-Schwarz model, RNS)On the real spacetime (Green-Schwarz model, GS)
RNS adds a new term to the SP actionThe new term is a Majorana spinor Ψ with two components(
Ψ−Ψ+
)It is fermionic in natureThe bosonic field X (σ, τ) stays, too.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
SUSY on the world-sheet: the RNS model
what is needed to eliminate tachyons and explain more thanthe graviton?Supersymetry (SUSY), inter aliaWhat is SUSY in string theory?
Mainly, it is an extra field that can be put:
On the worldsheet (Ramond-Neveu-Schwarz model, RNS)On the real spacetime (Green-Schwarz model, GS)
RNS adds a new term to the SP actionThe new term is a Majorana spinor Ψ with two components(
Ψ−Ψ+
)It is fermionic in natureThe bosonic field X (σ, τ) stays, too.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
SUSY on the world-sheet: the RNS model
what is needed to eliminate tachyons and explain more thanthe graviton?Supersymetry (SUSY), inter aliaWhat is SUSY in string theory?Mainly, it is an extra field that can be put:
On the worldsheet (Ramond-Neveu-Schwarz model, RNS)On the real spacetime (Green-Schwarz model, GS)
RNS adds a new term to the SP actionThe new term is a Majorana spinor Ψ with two components(
Ψ−Ψ+
)It is fermionic in natureThe bosonic field X (σ, τ) stays, too.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
SUSY on the world-sheet: the RNS model
what is needed to eliminate tachyons and explain more thanthe graviton?Supersymetry (SUSY), inter aliaWhat is SUSY in string theory?Mainly, it is an extra field that can be put:
On the worldsheet (Ramond-Neveu-Schwarz model, RNS)
On the real spacetime (Green-Schwarz model, GS)
RNS adds a new term to the SP actionThe new term is a Majorana spinor Ψ with two components(
Ψ−Ψ+
)It is fermionic in natureThe bosonic field X (σ, τ) stays, too.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
SUSY on the world-sheet: the RNS model
what is needed to eliminate tachyons and explain more thanthe graviton?Supersymetry (SUSY), inter aliaWhat is SUSY in string theory?Mainly, it is an extra field that can be put:
On the worldsheet (Ramond-Neveu-Schwarz model, RNS)On the real spacetime (Green-Schwarz model, GS)
RNS adds a new term to the SP actionThe new term is a Majorana spinor Ψ with two components(
Ψ−Ψ+
)It is fermionic in natureThe bosonic field X (σ, τ) stays, too.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
SUSY on the world-sheet: the RNS model
what is needed to eliminate tachyons and explain more thanthe graviton?Supersymetry (SUSY), inter aliaWhat is SUSY in string theory?Mainly, it is an extra field that can be put:
On the worldsheet (Ramond-Neveu-Schwarz model, RNS)On the real spacetime (Green-Schwarz model, GS)
RNS adds a new term to the SP action
The new term is a Majorana spinor Ψ with two components(Ψ−Ψ+
)It is fermionic in natureThe bosonic field X (σ, τ) stays, too.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
SUSY on the world-sheet: the RNS model
what is needed to eliminate tachyons and explain more thanthe graviton?Supersymetry (SUSY), inter aliaWhat is SUSY in string theory?Mainly, it is an extra field that can be put:
On the worldsheet (Ramond-Neveu-Schwarz model, RNS)On the real spacetime (Green-Schwarz model, GS)
RNS adds a new term to the SP actionThe new term is a Majorana spinor Ψ with two components(
Ψ−Ψ+
)
It is fermionic in natureThe bosonic field X (σ, τ) stays, too.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
SUSY on the world-sheet: the RNS model
what is needed to eliminate tachyons and explain more thanthe graviton?Supersymetry (SUSY), inter aliaWhat is SUSY in string theory?Mainly, it is an extra field that can be put:
On the worldsheet (Ramond-Neveu-Schwarz model, RNS)On the real spacetime (Green-Schwarz model, GS)
RNS adds a new term to the SP actionThe new term is a Majorana spinor Ψ with two components(
Ψ−Ψ+
)It is fermionic in nature
The bosonic field X (σ, τ) stays, too.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
SUSY on the world-sheet: the RNS model
what is needed to eliminate tachyons and explain more thanthe graviton?Supersymetry (SUSY), inter aliaWhat is SUSY in string theory?Mainly, it is an extra field that can be put:
On the worldsheet (Ramond-Neveu-Schwarz model, RNS)On the real spacetime (Green-Schwarz model, GS)
RNS adds a new term to the SP actionThe new term is a Majorana spinor Ψ with two components(
Ψ−Ψ+
)It is fermionic in natureThe bosonic field X (σ, τ) stays, too.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The SUSY transformation
With SUSY we need the new transformation ε.
It is a Majorana spinor, too.
The two transformations are now supersymmetric:{δXµ = εΨµ
δΨµ = −iρα∂αXµε
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The SUSY transformation
With SUSY we need the new transformation ε.
It is a Majorana spinor, too.
The two transformations are now supersymmetric:{δXµ = εΨµ
δΨµ = −iρα∂αXµε
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The SUSY transformation
With SUSY we need the new transformation ε.
It is a Majorana spinor, too.
The two transformations are now supersymmetric:{δXµ = εΨµ
δΨµ = −iρα∂αXµε
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The SUSY transformation
With SUSY we need the new transformation ε.
It is a Majorana spinor, too.
The two transformations are now supersymmetric:
{δXµ = εΨµ
δΨµ = −iρα∂αXµε
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
The SUSY transformation
With SUSY we need the new transformation ε.
It is a Majorana spinor, too.
The two transformations are now supersymmetric:{δXµ = εΨµ
δΨµ = −iρα∂αXµε
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Boundary conditions of the open string
Two movers (similar to progressive and regressive waves): leftmovers Ψµ
+ , right movers Ψµ−.
at σ = 0 we take:
Ψ+µ (0, τ) = Ψ−µ (0, τ)
Two types of boundary conditions at σ = π (called sectors):
Ramond (R) sector: Ψ+µ (π, τ) = Ψ−µ (π, τ)
Neveu-Schwarz (NS) sector: Ψ+µ (π, τ) = −Ψ−µ (π, τ)
Each b.c. gives different spectra. Moreover there are now 8combinations: open/closed strings, R/NS sectors, left/rightmovers
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Boundary conditions of the open string
Two movers (similar to progressive and regressive waves): leftmovers Ψµ
+ , right movers Ψµ−.
at σ = 0 we take:
Ψ+µ (0, τ) = Ψ−µ (0, τ)
Two types of boundary conditions at σ = π (called sectors):
Ramond (R) sector: Ψ+µ (π, τ) = Ψ−µ (π, τ)
Neveu-Schwarz (NS) sector: Ψ+µ (π, τ) = −Ψ−µ (π, τ)
Each b.c. gives different spectra. Moreover there are now 8combinations: open/closed strings, R/NS sectors, left/rightmovers
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Boundary conditions of the open string
Two movers (similar to progressive and regressive waves): leftmovers Ψµ
+ , right movers Ψµ−.
at σ = 0 we take:
Ψ+µ (0, τ) = Ψ−µ (0, τ)
Two types of boundary conditions at σ = π (called sectors):
Ramond (R) sector: Ψ+µ (π, τ) = Ψ−µ (π, τ)
Neveu-Schwarz (NS) sector: Ψ+µ (π, τ) = −Ψ−µ (π, τ)
Each b.c. gives different spectra. Moreover there are now 8combinations: open/closed strings, R/NS sectors, left/rightmovers
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Boundary conditions of the open string
Two movers (similar to progressive and regressive waves): leftmovers Ψµ
+ , right movers Ψµ−.
at σ = 0 we take:
Ψ+µ (0, τ) = Ψ−µ (0, τ)
Two types of boundary conditions at σ = π (called sectors):
Ramond (R) sector: Ψ+µ (π, τ) = Ψ−µ (π, τ)
Neveu-Schwarz (NS) sector: Ψ+µ (π, τ) = −Ψ−µ (π, τ)
Each b.c. gives different spectra. Moreover there are now 8combinations: open/closed strings, R/NS sectors, left/rightmovers
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Boundary conditions of the open string
Two movers (similar to progressive and regressive waves): leftmovers Ψµ
+ , right movers Ψµ−.
at σ = 0 we take:
Ψ+µ (0, τ) = Ψ−µ (0, τ)
Two types of boundary conditions at σ = π (called sectors):
Ramond (R) sector: Ψ+µ (π, τ) = Ψ−µ (π, τ)
Neveu-Schwarz (NS) sector: Ψ+µ (π, τ) = −Ψ−µ (π, τ)
Each b.c. gives different spectra. Moreover there are now 8combinations: open/closed strings, R/NS sectors, left/rightmovers
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Boundary conditions of the open string
Two movers (similar to progressive and regressive waves): leftmovers Ψµ
+ , right movers Ψµ−.
at σ = 0 we take:
Ψ+µ (0, τ) = Ψ−µ (0, τ)
Two types of boundary conditions at σ = π (called sectors):
Ramond (R) sector: Ψ+µ (π, τ) = Ψ−µ (π, τ)
Neveu-Schwarz (NS) sector: Ψ+µ (π, τ) = −Ψ−µ (π, τ)
Each b.c. gives different spectra. Moreover there are now 8combinations: open/closed strings, R/NS sectors, left/rightmovers
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Boundary conditions of the open string
Two movers (similar to progressive and regressive waves): leftmovers Ψµ
+ , right movers Ψµ−.
at σ = 0 we take:
Ψ+µ (0, τ) = Ψ−µ (0, τ)
Two types of boundary conditions at σ = π (called sectors):
Ramond (R) sector: Ψ+µ (π, τ) = Ψ−µ (π, τ)
Neveu-Schwarz (NS) sector: Ψ+µ (π, τ) = −Ψ−µ (π, τ)
Each b.c. gives different spectra. Moreover there are now 8combinations: open/closed strings, R/NS sectors, left/rightmovers
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
More spectra
Each sector has its own spectrum:
The R sector: Ψµ− (σ, τ) = 1√
2
∑n
dµn e−in(τ−σ)
Ψµ+ (σ, τ) = 1√
2
∑n
dµn e−in(τ+σ)
the NS sector: Ψµ− (σ, τ) = 1√
2
∑r
bµr e−ir(τ−σ)
Ψµ− (σ, τ) = 1√
2
∑r
bµr e−ir(τ+σ)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
More spectra
Each sector has its own spectrum:
The R sector: Ψµ− (σ, τ) = 1√
2
∑n
dµn e−in(τ−σ)
Ψµ+ (σ, τ) = 1√
2
∑n
dµn e−in(τ+σ)
the NS sector: Ψµ− (σ, τ) = 1√
2
∑r
bµr e−ir(τ−σ)
Ψµ− (σ, τ) = 1√
2
∑r
bµr e−ir(τ+σ)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
More spectra
Each sector has its own spectrum:
The R sector: Ψµ− (σ, τ) = 1√
2
∑n
dµn e−in(τ−σ)
Ψµ+ (σ, τ) = 1√
2
∑n
dµn e−in(τ+σ)
the NS sector: Ψµ− (σ, τ) = 1√
2
∑r
bµr e−ir(τ−σ)
Ψµ− (σ, τ) = 1√
2
∑r
bµr e−ir(τ+σ)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Quantization in RNS
Same procedure, but on the Majorana spinor.
Constraints to eliminate the negative norm states are calledsuper-Virasoro constraints.
Negative norm states can be eliminated as in bosonic ST.
Lorentz invariance is recovered
As a result, D=10.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Quantization in RNS
Same procedure, but on the Majorana spinor.
Constraints to eliminate the negative norm states are calledsuper-Virasoro constraints.
Negative norm states can be eliminated as in bosonic ST.
Lorentz invariance is recovered
As a result, D=10.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Quantization in RNS
Same procedure, but on the Majorana spinor.
Constraints to eliminate the negative norm states are calledsuper-Virasoro constraints.
Negative norm states can be eliminated as in bosonic ST.
Lorentz invariance is recovered
As a result, D=10.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Quantization in RNS
Same procedure, but on the Majorana spinor.
Constraints to eliminate the negative norm states are calledsuper-Virasoro constraints.
Negative norm states can be eliminated as in bosonic ST.
Lorentz invariance is recovered
As a result, D=10.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Quantization in RNS
Same procedure, but on the Majorana spinor.
Constraints to eliminate the negative norm states are calledsuper-Virasoro constraints.
Negative norm states can be eliminated as in bosonic ST.
Lorentz invariance is recovered
As a result, D=10.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Quantization in RNS
Same procedure, but on the Majorana spinor.
Constraints to eliminate the negative norm states are calledsuper-Virasoro constraints.
Negative norm states can be eliminated as in bosonic ST.
Lorentz invariance is recovered
As a result, D=10.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Sidestep: “simple” equations in ST?
Maybe the equation of motion of a superstring inlight-coordinate: {
∂+Ψµ− = ∂−Ψµ
+ = 0∂+∂−Xµ = 0
And its conservation laws:{∂+Ψµ
− = ∂−Ψµ+ = 0
∂−T++ = ∂+T−− = 0
can fit on a t-shirt
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Sidestep: “simple” equations in ST?
Maybe the equation of motion of a superstring inlight-coordinate: {
∂+Ψµ− = ∂−Ψµ
+ = 0∂+∂−Xµ = 0
And its conservation laws:{∂+Ψµ
− = ∂−Ψµ+ = 0
∂−T++ = ∂+T−− = 0
can fit on a t-shirt
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Sidestep: “simple” equations in ST?
Maybe the equation of motion of a superstring inlight-coordinate: {
∂+Ψµ− = ∂−Ψµ
+ = 0∂+∂−Xµ = 0
And its conservation laws:{∂+Ψµ
− = ∂−Ψµ+ = 0
∂−T++ = ∂+T−− = 0
can fit on a t-shirt
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
Sidestep: “simple” equations in ST?
Maybe the equation of motion of a superstring inlight-coordinate: {
∂+Ψµ− = ∂−Ψµ
+ = 0∂+∂−Xµ = 0
And its conservation laws:{∂+Ψµ
− = ∂−Ψµ+ = 0
∂−T++ = ∂+T−− = 0
can fit on a t-shirt
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
SUSY of the spacetime and the GS model
In GS (Green-Schwarz, mainly in ?) model, you put the SUSYon the real spacetime coordinates
Space becomes space+superspace
Coordinates are enlarge to:
(you bet) super-coordinates. θA (Grassman variables)
Super coordinates anticommute (unlike coordinates).On the worldsheet we have:
1 Xµ(σ, θ) and2 Θa(σ, θ) fields.
Each term contribute to the symmetry of the action and has asuper-Poincare group.
The Θ field has a special symmetry called “Kappa symmetry”.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
SUSY of the spacetime and the GS model
In GS (Green-Schwarz, mainly in ?) model, you put the SUSYon the real spacetime coordinates
Space becomes space+superspace
Coordinates are enlarge to:
(you bet) super-coordinates. θA (Grassman variables)
Super coordinates anticommute (unlike coordinates).On the worldsheet we have:
1 Xµ(σ, θ) and2 Θa(σ, θ) fields.
Each term contribute to the symmetry of the action and has asuper-Poincare group.
The Θ field has a special symmetry called “Kappa symmetry”.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
SUSY of the spacetime and the GS model
In GS (Green-Schwarz, mainly in ?) model, you put the SUSYon the real spacetime coordinates
Space becomes space+superspace
Coordinates are enlarge to:
(you bet) super-coordinates. θA (Grassman variables)
Super coordinates anticommute (unlike coordinates).On the worldsheet we have:
1 Xµ(σ, θ) and2 Θa(σ, θ) fields.
Each term contribute to the symmetry of the action and has asuper-Poincare group.
The Θ field has a special symmetry called “Kappa symmetry”.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
SUSY of the spacetime and the GS model
In GS (Green-Schwarz, mainly in ?) model, you put the SUSYon the real spacetime coordinates
Space becomes space+superspace
Coordinates are enlarge to:
(you bet) super-coordinates. θA (Grassman variables)
Super coordinates anticommute (unlike coordinates).On the worldsheet we have:
1 Xµ(σ, θ) and2 Θa(σ, θ) fields.
Each term contribute to the symmetry of the action and has asuper-Poincare group.
The Θ field has a special symmetry called “Kappa symmetry”.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
SUSY of the spacetime and the GS model
In GS (Green-Schwarz, mainly in ?) model, you put the SUSYon the real spacetime coordinates
Space becomes space+superspace
Coordinates are enlarge to:
(you bet) super-coordinates. θA (Grassman variables)
Super coordinates anticommute (unlike coordinates).On the worldsheet we have:
1 Xµ(σ, θ) and2 Θa(σ, θ) fields.
Each term contribute to the symmetry of the action and has asuper-Poincare group.
The Θ field has a special symmetry called “Kappa symmetry”.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
SUSY of the spacetime and the GS model
In GS (Green-Schwarz, mainly in ?) model, you put the SUSYon the real spacetime coordinates
Space becomes space+superspace
Coordinates are enlarge to:
(you bet) super-coordinates. θA (Grassman variables)
Super coordinates anticommute (unlike coordinates).
On the worldsheet we have:
1 Xµ(σ, θ) and2 Θa(σ, θ) fields.
Each term contribute to the symmetry of the action and has asuper-Poincare group.
The Θ field has a special symmetry called “Kappa symmetry”.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
SUSY of the spacetime and the GS model
In GS (Green-Schwarz, mainly in ?) model, you put the SUSYon the real spacetime coordinates
Space becomes space+superspace
Coordinates are enlarge to:
(you bet) super-coordinates. θA (Grassman variables)
Super coordinates anticommute (unlike coordinates).On the worldsheet we have:
1 Xµ(σ, θ) and2 Θa(σ, θ) fields.
Each term contribute to the symmetry of the action and has asuper-Poincare group.
The Θ field has a special symmetry called “Kappa symmetry”.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
SUSY of the spacetime and the GS model
In GS (Green-Schwarz, mainly in ?) model, you put the SUSYon the real spacetime coordinates
Space becomes space+superspace
Coordinates are enlarge to:
(you bet) super-coordinates. θA (Grassman variables)
Super coordinates anticommute (unlike coordinates).On the worldsheet we have:
1 Xµ(σ, θ) and
2 Θa(σ, θ) fields.
Each term contribute to the symmetry of the action and has asuper-Poincare group.
The Θ field has a special symmetry called “Kappa symmetry”.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
SUSY of the spacetime and the GS model
In GS (Green-Schwarz, mainly in ?) model, you put the SUSYon the real spacetime coordinates
Space becomes space+superspace
Coordinates are enlarge to:
(you bet) super-coordinates. θA (Grassman variables)
Super coordinates anticommute (unlike coordinates).On the worldsheet we have:
1 Xµ(σ, θ) and2 Θa(σ, θ) fields.
Each term contribute to the symmetry of the action and has asuper-Poincare group.
The Θ field has a special symmetry called “Kappa symmetry”.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
SUSY of the spacetime and the GS model
In GS (Green-Schwarz, mainly in ?) model, you put the SUSYon the real spacetime coordinates
Space becomes space+superspace
Coordinates are enlarge to:
(you bet) super-coordinates. θA (Grassman variables)
Super coordinates anticommute (unlike coordinates).On the worldsheet we have:
1 Xµ(σ, θ) and2 Θa(σ, θ) fields.
Each term contribute to the symmetry of the action and has asuper-Poincare group.
The Θ field has a special symmetry called “Kappa symmetry”.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
SUSY of the spacetime and the GS model
In GS (Green-Schwarz, mainly in ?) model, you put the SUSYon the real spacetime coordinates
Space becomes space+superspace
Coordinates are enlarge to:
(you bet) super-coordinates. θA (Grassman variables)
Super coordinates anticommute (unlike coordinates).On the worldsheet we have:
1 Xµ(σ, θ) and2 Θa(σ, θ) fields.
Each term contribute to the symmetry of the action and has asuper-Poincare group.
The Θ field has a special symmetry called “Kappa symmetry”.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
GS quantization
Very difficult to quantize
Needs special decomposition
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
GS quantization
Very difficult to quantize
Needs special decomposition
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
GS quantization
Very difficult to quantize
Needs special decomposition
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
How many super-symmetries?
There is no sense to have N > 2.
Usually two cases:
N=1, one Grassman number, one fermionic coordinate, henceType-I STN=2 there are two fermionic coordinates (spinors) on theworldsheet, hence Type-II ST
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
How many super-symmetries?
There is no sense to have N > 2.
Usually two cases:
N=1, one Grassman number, one fermionic coordinate, henceType-I STN=2 there are two fermionic coordinates (spinors) on theworldsheet, hence Type-II ST
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
How many super-symmetries?
There is no sense to have N > 2.
Usually two cases:
N=1, one Grassman number, one fermionic coordinate, henceType-I STN=2 there are two fermionic coordinates (spinors) on theworldsheet, hence Type-II ST
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
How many super-symmetries?
There is no sense to have N > 2.
Usually two cases:
N=1, one Grassman number, one fermionic coordinate, henceType-I ST
N=2 there are two fermionic coordinates (spinors) on theworldsheet, hence Type-II ST
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
How many super-symmetries?
There is no sense to have N > 2.
Usually two cases:
N=1, one Grassman number, one fermionic coordinate, henceType-I STN=2 there are two fermionic coordinates (spinors) on theworldsheet, hence Type-II ST
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
D-branes are for Yang-Mills fields
They exist in the spacetime and they are the surfaces wherestrings end.
they mesh well with non-supersymmetric ST (such as bosonicST) but better with superstring theory.
D-branes are usually used to infer all forces of the StandardModel.
The current understanding is that gravitation escapes thebranes.
N=2 there are two fermionic coordinates (spinors) on theworldsheet, hence Type-II ST
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
D-branes are for Yang-Mills fields
They exist in the spacetime and they are the surfaces wherestrings end.
they mesh well with non-supersymmetric ST (such as bosonicST) but better with superstring theory.
D-branes are usually used to infer all forces of the StandardModel.
The current understanding is that gravitation escapes thebranes.
N=2 there are two fermionic coordinates (spinors) on theworldsheet, hence Type-II ST
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
D-branes are for Yang-Mills fields
They exist in the spacetime and they are the surfaces wherestrings end.
they mesh well with non-supersymmetric ST (such as bosonicST) but better with superstring theory.
D-branes are usually used to infer all forces of the StandardModel.
The current understanding is that gravitation escapes thebranes.
N=2 there are two fermionic coordinates (spinors) on theworldsheet, hence Type-II ST
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
D-branes are for Yang-Mills fields
They exist in the spacetime and they are the surfaces wherestrings end.
they mesh well with non-supersymmetric ST (such as bosonicST) but better with superstring theory.
D-branes are usually used to infer all forces of the StandardModel.
The current understanding is that gravitation escapes thebranes.
N=2 there are two fermionic coordinates (spinors) on theworldsheet, hence Type-II ST
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
D-branes are for Yang-Mills fields
They exist in the spacetime and they are the surfaces wherestrings end.
they mesh well with non-supersymmetric ST (such as bosonicST) but better with superstring theory.
D-branes are usually used to infer all forces of the StandardModel.
The current understanding is that gravitation escapes thebranes.
N=2 there are two fermionic coordinates (spinors) on theworldsheet, hence Type-II ST
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Some assumptionsString unificationProblems at the foundationSUSY = Super-symmetrySkip: Background dependenceThe toy bosonic string theoryTwo SUSYsThe D-branes
D-branes are for Yang-Mills fields
They exist in the spacetime and they are the surfaces wherestrings end.
they mesh well with non-supersymmetric ST (such as bosonicST) but better with superstring theory.
D-branes are usually used to infer all forces of the StandardModel.
The current understanding is that gravitation escapes thebranes.
N=2 there are two fermionic coordinates (spinors) on theworldsheet, hence Type-II ST
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
What string explanation could look like
Some constraints do explain in string theory.
By eliminating the ghost field in bosonic string theory you geta spin-2 field
In order to eliminate tachyons one needs to move tosupersymmetry
explaining away anomalies of the standard model one can gaininsight into the nature of the duality between bosons andfermions
all these look like unexpected explanations (and some actuallywork)
Unification is not necessarily the engine of these explanations.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
What string explanation could look like
Some constraints do explain in string theory.
By eliminating the ghost field in bosonic string theory you geta spin-2 field
In order to eliminate tachyons one needs to move tosupersymmetry
explaining away anomalies of the standard model one can gaininsight into the nature of the duality between bosons andfermions
all these look like unexpected explanations (and some actuallywork)
Unification is not necessarily the engine of these explanations.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
What string explanation could look like
Some constraints do explain in string theory.
By eliminating the ghost field in bosonic string theory you geta spin-2 field
In order to eliminate tachyons one needs to move tosupersymmetry
explaining away anomalies of the standard model one can gaininsight into the nature of the duality between bosons andfermions
all these look like unexpected explanations (and some actuallywork)
Unification is not necessarily the engine of these explanations.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
What string explanation could look like
Some constraints do explain in string theory.
By eliminating the ghost field in bosonic string theory you geta spin-2 field
In order to eliminate tachyons one needs to move tosupersymmetry
explaining away anomalies of the standard model one can gaininsight into the nature of the duality between bosons andfermions
all these look like unexpected explanations (and some actuallywork)
Unification is not necessarily the engine of these explanations.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
What string explanation could look like
Some constraints do explain in string theory.
By eliminating the ghost field in bosonic string theory you geta spin-2 field
In order to eliminate tachyons one needs to move tosupersymmetry
explaining away anomalies of the standard model one can gaininsight into the nature of the duality between bosons andfermions
all these look like unexpected explanations (and some actuallywork)
Unification is not necessarily the engine of these explanations.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
What string explanation could look like
Some constraints do explain in string theory.
By eliminating the ghost field in bosonic string theory you geta spin-2 field
In order to eliminate tachyons one needs to move tosupersymmetry
explaining away anomalies of the standard model one can gaininsight into the nature of the duality between bosons andfermions
all these look like unexpected explanations (and some actuallywork)
Unification is not necessarily the engine of these explanations.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
Facts, constants, and string theory
One can try to explain Λ, but it is not that easy. There areno-go results
Explain why Newton’s constant is small by heterotic stringtheory in two regimes: strong coupling and weak coupling.
There are attempts to explain Big-Bang, SSB ,etc. bysmoothing out singularities before Big-Bang
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
Facts, constants, and string theory
One can try to explain Λ, but it is not that easy. There areno-go results
Explain why Newton’s constant is small by heterotic stringtheory in two regimes: strong coupling and weak coupling.
There are attempts to explain Big-Bang, SSB ,etc. bysmoothing out singularities before Big-Bang
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
Facts, constants, and string theory
One can try to explain Λ, but it is not that easy. There areno-go results
Explain why Newton’s constant is small by heterotic stringtheory in two regimes: strong coupling and weak coupling.
There are attempts to explain Big-Bang, SSB ,etc. bysmoothing out singularities before Big-Bang
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
Facts, constants, and string theory
One can try to explain Λ, but it is not that easy. There areno-go results
Explain why Newton’s constant is small by heterotic stringtheory in two regimes: strong coupling and weak coupling.
There are attempts to explain Big-Bang, SSB ,etc. bysmoothing out singularities before Big-Bang
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
Fermions out of string theory?
Can we infer fermions? No
But we can write down the fermionic and bosonic fields
Is this enough?
No, the usual Yang-Mills symmetries are missing.
ST in this formulation does not produce YM symmetries, butfermionic fields
These are not physical or spacetime bosons and fermions.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
Fermions out of string theory?
Can we infer fermions? No
But we can write down the fermionic and bosonic fields
Is this enough?
No, the usual Yang-Mills symmetries are missing.
ST in this formulation does not produce YM symmetries, butfermionic fields
These are not physical or spacetime bosons and fermions.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
Fermions out of string theory?
Can we infer fermions? No
But we can write down the fermionic and bosonic fields
Is this enough?
No, the usual Yang-Mills symmetries are missing.
ST in this formulation does not produce YM symmetries, butfermionic fields
These are not physical or spacetime bosons and fermions.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
Fermions out of string theory?
Can we infer fermions? No
But we can write down the fermionic and bosonic fields
Is this enough?
No, the usual Yang-Mills symmetries are missing.
ST in this formulation does not produce YM symmetries, butfermionic fields
These are not physical or spacetime bosons and fermions.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
Fermions out of string theory?
Can we infer fermions? No
But we can write down the fermionic and bosonic fields
Is this enough?
No, the usual Yang-Mills symmetries are missing.
ST in this formulation does not produce YM symmetries, butfermionic fields
These are not physical or spacetime bosons and fermions.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
Fermions out of string theory?
Can we infer fermions? No
But we can write down the fermionic and bosonic fields
Is this enough?
No, the usual Yang-Mills symmetries are missing.
ST in this formulation does not produce YM symmetries, butfermionic fields
These are not physical or spacetime bosons and fermions.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
Fermions out of string theory?
Can we infer fermions? No
But we can write down the fermionic and bosonic fields
Is this enough?
No, the usual Yang-Mills symmetries are missing.
ST in this formulation does not produce YM symmetries, butfermionic fields
These are not physical or spacetime bosons and fermions.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
Standard Model out of string theory? Go statistical
It is possible and doable
But: too many consistent string models that do theexplanatory job
String theory needs to explain its own limitation and thechoice of the right model
YOu need to explain your choice of string model. You can dothis by a statistical approach to models.
String theory needs the concept of naturalness
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
Standard Model out of string theory? Go statistical
It is possible and doable
But: too many consistent string models that do theexplanatory job
String theory needs to explain its own limitation and thechoice of the right model
YOu need to explain your choice of string model. You can dothis by a statistical approach to models.
String theory needs the concept of naturalness
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
Standard Model out of string theory? Go statistical
It is possible and doable
But: too many consistent string models that do theexplanatory job
String theory needs to explain its own limitation and thechoice of the right model
YOu need to explain your choice of string model. You can dothis by a statistical approach to models.
String theory needs the concept of naturalness
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
Standard Model out of string theory? Go statistical
It is possible and doable
But: too many consistent string models that do theexplanatory job
String theory needs to explain its own limitation and thechoice of the right model
YOu need to explain your choice of string model. You can dothis by a statistical approach to models.
String theory needs the concept of naturalness
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
Standard Model out of string theory? Go statistical
It is possible and doable
But: too many consistent string models that do theexplanatory job
String theory needs to explain its own limitation and thechoice of the right model
YOu need to explain your choice of string model. You can dothis by a statistical approach to models.
String theory needs the concept of naturalness
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
Standard Model out of string theory? Go statistical
It is possible and doable
But: too many consistent string models that do theexplanatory job
String theory needs to explain its own limitation and thechoice of the right model
YOu need to explain your choice of string model. You can dothis by a statistical approach to models.
String theory needs the concept of naturalness
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
GSO projection: a farewell to tachyons
Several attempts were made in order to eliminate tachyons
But the RNS still contains the annoying tachyonic field.
There is a procedure called GSO (Gliozzi, Scherk, Olive) (?,Ch. 4)
a parity operator G is defined (determines the number offermionic oscillations).
we keep only the states with a positive G-parity.
this eliminates tachyons.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
GSO projection: a farewell to tachyons
Several attempts were made in order to eliminate tachyons
But the RNS still contains the annoying tachyonic field.
There is a procedure called GSO (Gliozzi, Scherk, Olive) (?,Ch. 4)
a parity operator G is defined (determines the number offermionic oscillations).
we keep only the states with a positive G-parity.
this eliminates tachyons.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
GSO projection: a farewell to tachyons
Several attempts were made in order to eliminate tachyons
But the RNS still contains the annoying tachyonic field.
There is a procedure called GSO (Gliozzi, Scherk, Olive) (?,Ch. 4)
a parity operator G is defined (determines the number offermionic oscillations).
we keep only the states with a positive G-parity.
this eliminates tachyons.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
GSO projection: a farewell to tachyons
Several attempts were made in order to eliminate tachyons
But the RNS still contains the annoying tachyonic field.
There is a procedure called GSO (Gliozzi, Scherk, Olive) (?,Ch. 4)
a parity operator G is defined (determines the number offermionic oscillations).
we keep only the states with a positive G-parity.
this eliminates tachyons.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
GSO projection: a farewell to tachyons
Several attempts were made in order to eliminate tachyons
But the RNS still contains the annoying tachyonic field.
There is a procedure called GSO (Gliozzi, Scherk, Olive) (?,Ch. 4)
a parity operator G is defined (determines the number offermionic oscillations).
we keep only the states with a positive G-parity.
this eliminates tachyons.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
GSO projection: a farewell to tachyons
Several attempts were made in order to eliminate tachyons
But the RNS still contains the annoying tachyonic field.
There is a procedure called GSO (Gliozzi, Scherk, Olive) (?,Ch. 4)
a parity operator G is defined (determines the number offermionic oscillations).
we keep only the states with a positive G-parity.
this eliminates tachyons.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
GSO projection: a farewell to tachyons
Several attempts were made in order to eliminate tachyons
But the RNS still contains the annoying tachyonic field.
There is a procedure called GSO (Gliozzi, Scherk, Olive) (?,Ch. 4)
a parity operator G is defined (determines the number offermionic oscillations).
we keep only the states with a positive G-parity.
this eliminates tachyons.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
Unexpected failures: some morals
RNS model is not able to eliminate tachyons without the GSOprojection condition
the GSO in general is considered ad-hoc
RNS model is not able to infer the Standard Model
that is possible only with:
D-branes OR
Charges on the endpoints of strings AND
SUSY on the spacetime manifold (the GS model)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
Unexpected failures: some morals
RNS model is not able to eliminate tachyons without the GSOprojection condition
the GSO in general is considered ad-hoc
RNS model is not able to infer the Standard Model
that is possible only with:
D-branes OR
Charges on the endpoints of strings AND
SUSY on the spacetime manifold (the GS model)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
Unexpected failures: some morals
RNS model is not able to eliminate tachyons without the GSOprojection condition
the GSO in general is considered ad-hoc
RNS model is not able to infer the Standard Model
that is possible only with:
D-branes OR
Charges on the endpoints of strings AND
SUSY on the spacetime manifold (the GS model)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
Unexpected failures: some morals
RNS model is not able to eliminate tachyons without the GSOprojection condition
the GSO in general is considered ad-hoc
RNS model is not able to infer the Standard Model
that is possible only with:
D-branes OR
Charges on the endpoints of strings AND
SUSY on the spacetime manifold (the GS model)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
Unexpected failures: some morals
RNS model is not able to eliminate tachyons without the GSOprojection condition
the GSO in general is considered ad-hoc
RNS model is not able to infer the Standard Model
that is possible only with:
D-branes OR
Charges on the endpoints of strings AND
SUSY on the spacetime manifold (the GS model)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
Unexpected failures: some morals
RNS model is not able to eliminate tachyons without the GSOprojection condition
the GSO in general is considered ad-hoc
RNS model is not able to infer the Standard Model
that is possible only with:
D-branes OR
Charges on the endpoints of strings AND
SUSY on the spacetime manifold (the GS model)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
Unexpected failures: some morals
RNS model is not able to eliminate tachyons without the GSOprojection condition
the GSO in general is considered ad-hoc
RNS model is not able to infer the Standard Model
that is possible only with:
D-branes OR
Charges on the endpoints of strings AND
SUSY on the spacetime manifold (the GS model)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Naive explanationsSophisticated cases of string explanations
Unexpected failures: some morals
RNS model is not able to eliminate tachyons without the GSOprojection condition
the GSO in general is considered ad-hoc
RNS model is not able to infer the Standard Model
that is possible only with:
D-branes OR
Charges on the endpoints of strings AND
SUSY on the spacetime manifold (the GS model)
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Rejoinders
Why do you decouple unification from explanation?
Are these indeed explanations or mere consequences of thestring mathematics?
If there is such an explanatory mismatch, do we still talkabout string theory and a fundamental theory? It is a goodcandidate for the ultimate/GUT?
can you connect explanatory advantages toprediction/confirmation advantages? If not, is this science?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Rejoinders
Why do you decouple unification from explanation?
Are these indeed explanations or mere consequences of thestring mathematics?
If there is such an explanatory mismatch, do we still talkabout string theory and a fundamental theory? It is a goodcandidate for the ultimate/GUT?
can you connect explanatory advantages toprediction/confirmation advantages? If not, is this science?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Rejoinders
Why do you decouple unification from explanation?
Are these indeed explanations or mere consequences of thestring mathematics?
If there is such an explanatory mismatch, do we still talkabout string theory and a fundamental theory? It is a goodcandidate for the ultimate/GUT?
can you connect explanatory advantages toprediction/confirmation advantages? If not, is this science?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Rejoinders
Why do you decouple unification from explanation?
Are these indeed explanations or mere consequences of thestring mathematics?
If there is such an explanatory mismatch, do we still talkabout string theory and a fundamental theory? It is a goodcandidate for the ultimate/GUT?
can you connect explanatory advantages toprediction/confirmation advantages? If not, is this science?
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
A suggestion
Perhaps we need to look at string explanations in the sameway we bridge by explanation the domain of psychology andneuroscience
Not all physical events of the brain are mirrored onto a mentalstate and viceversa
There is an explanatory gap there.
String theory is not completely explanatory when it comes toStandard Model and General Relativity
Reduction does not work here.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
A suggestion
Perhaps we need to look at string explanations in the sameway we bridge by explanation the domain of psychology andneuroscience
Not all physical events of the brain are mirrored onto a mentalstate and viceversa
There is an explanatory gap there.
String theory is not completely explanatory when it comes toStandard Model and General Relativity
Reduction does not work here.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
A suggestion
Perhaps we need to look at string explanations in the sameway we bridge by explanation the domain of psychology andneuroscience
Not all physical events of the brain are mirrored onto a mentalstate and viceversa
There is an explanatory gap there.
String theory is not completely explanatory when it comes toStandard Model and General Relativity
Reduction does not work here.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
A suggestion
Perhaps we need to look at string explanations in the sameway we bridge by explanation the domain of psychology andneuroscience
Not all physical events of the brain are mirrored onto a mentalstate and viceversa
There is an explanatory gap there.
String theory is not completely explanatory when it comes toStandard Model and General Relativity
Reduction does not work here.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
A suggestion
Perhaps we need to look at string explanations in the sameway we bridge by explanation the domain of psychology andneuroscience
Not all physical events of the brain are mirrored onto a mentalstate and viceversa
There is an explanatory gap there.
String theory is not completely explanatory when it comes toStandard Model and General Relativity
Reduction does not work here.
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Conclusion
There is explanation at work in string theory
IT does not look strongly coupled to unificaiton
It is novel and unexpected
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Conclusion
There is explanation at work in string theory
IT does not look strongly coupled to unificaiton
It is novel and unexpected
Ioan Muntean String Theory: Explanation and Fundamentalism
Philosophy and Quantum Gravity programsExplanation and string theory
The nutshell version of string theorySome case studies of string explanations
Rejoinders and Conclusion
Conclusion
There is explanation at work in string theory
IT does not look strongly coupled to unificaiton
It is novel and unexpected
Ioan Muntean String Theory: Explanation and Fundamentalism