Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Chaos and the Strange Geometry of theUniverse

Will Abram

Department of MathematicsUniversity of Michigan at Ann Arbor and Ridgeview Classical Schools

Humanities Day, Ridgeview Classical SchoolsFebruary 2, 2013

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Outline

1 Introduction: The Problem of Modern Physics

2 Superstring Theory, M-Theory, and Grand Unification

3 A Stranger World: Some Implications of String Theory

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Outline

1 Introduction: The Problem of Modern Physics

2 Superstring Theory, M-Theory, and Grand Unification

3 A Stranger World: Some Implications of String Theory

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

The Problem of Modern Physics

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

First Conflict of Physics

Maxwell’s Theory of Electromagnetism: speed of light ismaximalThis is in conflict with Newton’s laws of motionEinstein’s solution: Special Relativity

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

First Conflict of Physics

Maxwell’s Theory of Electromagnetism: speed of light ismaximalThis is in conflict with Newton’s laws of motionEinstein’s solution: Special Relativity

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

First Conflict of Physics

Maxwell’s Theory of Electromagnetism: speed of light ismaximalThis is in conflict with Newton’s laws of motionEinstein’s solution: Special Relativity

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Special Relativity

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Special Relativity

The Principle of Relativity: there is no such thing asabsolute velocityRather, a frame of reference must always be specifiedRegardless of referential frame, light always travels at lightspeed (c ≈ 3.0 × 108 m/s ≈ 6.7 × 108 mi/hr)Einstein theorized that all matter moves through4-dimensional spacetime at precisely the speed of lightIncreasing velocity in the space dimension decreasesvelocity in the time dimension

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Special Relativity

The Principle of Relativity: there is no such thing asabsolute velocityRather, a frame of reference must always be specifiedRegardless of referential frame, light always travels at lightspeed (c ≈ 3.0 × 108 m/s ≈ 6.7 × 108 mi/hr)Einstein theorized that all matter moves through4-dimensional spacetime at precisely the speed of lightIncreasing velocity in the space dimension decreasesvelocity in the time dimension

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Special Relativity

The Principle of Relativity: there is no such thing asabsolute velocityRather, a frame of reference must always be specifiedRegardless of referential frame, light always travels at lightspeed (c ≈ 3.0 × 108 m/s ≈ 6.7 × 108 mi/hr)Einstein theorized that all matter moves through4-dimensional spacetime at precisely the speed of lightIncreasing velocity in the space dimension decreasesvelocity in the time dimension

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Special Relativity

The Principle of Relativity: there is no such thing asabsolute velocityRather, a frame of reference must always be specifiedRegardless of referential frame, light always travels at lightspeed (c ≈ 3.0 × 108 m/s ≈ 6.7 × 108 mi/hr)Einstein theorized that all matter moves through4-dimensional spacetime at precisely the speed of lightIncreasing velocity in the space dimension decreasesvelocity in the time dimension

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Special Relativity

The Principle of Relativity: there is no such thing asabsolute velocityRather, a frame of reference must always be specifiedRegardless of referential frame, light always travels at lightspeed (c ≈ 3.0 × 108 m/s ≈ 6.7 × 108 mi/hr)Einstein theorized that all matter moves through4-dimensional spacetime at precisely the speed of lightIncreasing velocity in the space dimension decreasesvelocity in the time dimension

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Implications of Special Relativity

Every photon is as young today as it was at the beginningof the universeRegardless of your motion, light always approaches andretreats from you with velocity cTime, including even the simultaneity of events, is relativeNOTHING can travel faster than the speed of lightTraveling at velocity v increases mass by the Lorentz factorγ = 1√

1− v2

c2

Objects also contract in the direction of travelE = mc2: Einstein noticed that energy and matter areconvertible currencies

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Implications of Special Relativity

Every photon is as young today as it was at the beginningof the universeRegardless of your motion, light always approaches andretreats from you with velocity cTime, including even the simultaneity of events, is relativeNOTHING can travel faster than the speed of lightTraveling at velocity v increases mass by the Lorentz factorγ = 1√

1− v2

c2

Objects also contract in the direction of travelE = mc2: Einstein noticed that energy and matter areconvertible currencies

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Implications of Special Relativity

Every photon is as young today as it was at the beginningof the universeRegardless of your motion, light always approaches andretreats from you with velocity cTime, including even the simultaneity of events, is relativeNOTHING can travel faster than the speed of lightTraveling at velocity v increases mass by the Lorentz factorγ = 1√

1− v2

c2

Objects also contract in the direction of travelE = mc2: Einstein noticed that energy and matter areconvertible currencies

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Implications of Special Relativity

Every photon is as young today as it was at the beginningof the universeRegardless of your motion, light always approaches andretreats from you with velocity cTime, including even the simultaneity of events, is relativeNOTHING can travel faster than the speed of lightTraveling at velocity v increases mass by the Lorentz factorγ = 1√

1− v2

c2

Objects also contract in the direction of travelE = mc2: Einstein noticed that energy and matter areconvertible currencies

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Implications of Special Relativity

Every photon is as young today as it was at the beginningof the universeRegardless of your motion, light always approaches andretreats from you with velocity cTime, including even the simultaneity of events, is relativeNOTHING can travel faster than the speed of lightTraveling at velocity v increases mass by the Lorentz factorγ = 1√

1− v2

c2

Objects also contract in the direction of travelE = mc2: Einstein noticed that energy and matter areconvertible currencies

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Implications of Special Relativity

Every photon is as young today as it was at the beginningof the universeRegardless of your motion, light always approaches andretreats from you with velocity cTime, including even the simultaneity of events, is relativeNOTHING can travel faster than the speed of lightTraveling at velocity v increases mass by the Lorentz factorγ = 1√

1− v2

c2

Objects also contract in the direction of travelE = mc2: Einstein noticed that energy and matter areconvertible currencies

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Implications of Special Relativity

Every photon is as young today as it was at the beginningof the universeRegardless of your motion, light always approaches andretreats from you with velocity cTime, including even the simultaneity of events, is relativeNOTHING can travel faster than the speed of lightTraveling at velocity v increases mass by the Lorentz factorγ = 1√

1− v2

c2

Objects also contract in the direction of travelE = mc2: Einstein noticed that energy and matter areconvertible currencies

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Second Conflict of Physics

The Newtonian theory of gravity implies that gravity actsinstantaneouslyThis is at odds with special relativity, since nothing,including forces, can travel faster than lightEinstein’s solution: General Relativity

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Second Conflict of Physics

The Newtonian theory of gravity implies that gravity actsinstantaneouslyThis is at odds with special relativity, since nothing,including forces, can travel faster than lightEinstein’s solution: General Relativity

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Second Conflict of Physics

The Newtonian theory of gravity implies that gravity actsinstantaneouslyThis is at odds with special relativity, since nothing,including forces, can travel faster than lightEinstein’s solution: General Relativity

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

General Relativity

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

General Relativity

The Equivalence Principle: even observers undergoingaccelerated motion can claim to be at rest if theyincorporate gravityThat is: gravity and accelerated motion are dual conceptsAccording to Einstein, the mechanism of gravity is theliteral warping of spacetimeGravitons, the force particles of gravity, travel at the speedof lightGravitational disturbances ripple like waves on the oceanof the spacial fabric, and DO NOT travel instantaneously

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

General Relativity

The Equivalence Principle: even observers undergoingaccelerated motion can claim to be at rest if theyincorporate gravityThat is: gravity and accelerated motion are dual conceptsAccording to Einstein, the mechanism of gravity is theliteral warping of spacetimeGravitons, the force particles of gravity, travel at the speedof lightGravitational disturbances ripple like waves on the oceanof the spacial fabric, and DO NOT travel instantaneously

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

General Relativity

The Equivalence Principle: even observers undergoingaccelerated motion can claim to be at rest if theyincorporate gravityThat is: gravity and accelerated motion are dual conceptsAccording to Einstein, the mechanism of gravity is theliteral warping of spacetimeGravitons, the force particles of gravity, travel at the speedof lightGravitational disturbances ripple like waves on the oceanof the spacial fabric, and DO NOT travel instantaneously

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

General Relativity

The Equivalence Principle: even observers undergoingaccelerated motion can claim to be at rest if theyincorporate gravityThat is: gravity and accelerated motion are dual conceptsAccording to Einstein, the mechanism of gravity is theliteral warping of spacetimeGravitons, the force particles of gravity, travel at the speedof lightGravitational disturbances ripple like waves on the oceanof the spacial fabric, and DO NOT travel instantaneously

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

General Relativity

The Equivalence Principle: even observers undergoingaccelerated motion can claim to be at rest if theyincorporate gravityThat is: gravity and accelerated motion are dual conceptsAccording to Einstein, the mechanism of gravity is theliteral warping of spacetimeGravitons, the force particles of gravity, travel at the speedof lightGravitational disturbances ripple like waves on the oceanof the spacial fabric, and DO NOT travel instantaneously

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Implications of and Evidence for General Relativity

Schwarzchild’s Solution: if enough mass is concentrated ina small enough region, its gravitational force will consumeeverthing nearby, including light (a black hole)The overall size of the spatial universe must be changingover time: Einstein’s cosmological constantGeneral relativity has been confirmed by a mountain ofexperimental evidenceThe first confirmation: Solar Eclipse

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Implications of and Evidence for General Relativity

Schwarzchild’s Solution: if enough mass is concentrated ina small enough region, its gravitational force will consumeeverthing nearby, including light (a black hole)The overall size of the spatial universe must be changingover time: Einstein’s cosmological constantGeneral relativity has been confirmed by a mountain ofexperimental evidenceThe first confirmation: Solar Eclipse

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Implications of and Evidence for General Relativity

Schwarzchild’s Solution: if enough mass is concentrated ina small enough region, its gravitational force will consumeeverthing nearby, including light (a black hole)The overall size of the spatial universe must be changingover time: Einstein’s cosmological constantGeneral relativity has been confirmed by a mountain ofexperimental evidenceThe first confirmation: Solar Eclipse

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Implications of and Evidence for General Relativity

Schwarzchild’s Solution: if enough mass is concentrated ina small enough region, its gravitational force will consumeeverthing nearby, including light (a black hole)The overall size of the spatial universe must be changingover time: Einstein’s cosmological constantGeneral relativity has been confirmed by a mountain ofexperimental evidenceThe first confirmation: Solar Eclipse

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Microscopic Behaior: Quantum Mechanics

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Quantum Mechanics 1: Planck’s Constant

Using classical mechanics, the computation of the energyin a hot oven yields an infinite amountPlanck resolved this by showing that the minimum energya wave can carry is proportional to its frequencyThe constant of proportionality, called Planck’s Constant, is~ ≈ 6.6 × 10−16eV · s

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Quantum Mechanics 1: Planck’s Constant

Using classical mechanics, the computation of the energyin a hot oven yields an infinite amountPlanck resolved this by showing that the minimum energya wave can carry is proportional to its frequencyThe constant of proportionality, called Planck’s Constant, is~ ≈ 6.6 × 10−16eV · s

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Quantum Mechanics 1: Planck’s Constant

Using classical mechanics, the computation of the energyin a hot oven yields an infinite amountPlanck resolved this by showing that the minimum energya wave can carry is proportional to its frequencyThe constant of proportionality, called Planck’s Constant, is~ ≈ 6.6 × 10−16eV · s

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Quantum Mechanics 2: The Photoelectric Effect

When light is shined on certain metals, energized electronsare emittedPuzzlingly, the number electrons emitted depends only onthe frequency of the light sourceAt low enough frequencies, regardless of the intensity of alight source, no electrons are emittedEinstein’s explanation: photonsEnergy of photons are proportional to the frequencies oflight waves

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Quantum Mechanics 2: The Photoelectric Effect

When light is shined on certain metals, energized electronsare emittedPuzzlingly, the number electrons emitted depends only onthe frequency of the light sourceAt low enough frequencies, regardless of the intensity of alight source, no electrons are emittedEinstein’s explanation: photonsEnergy of photons are proportional to the frequencies oflight waves

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Quantum Mechanics 2: The Photoelectric Effect

When light is shined on certain metals, energized electronsare emittedPuzzlingly, the number electrons emitted depends only onthe frequency of the light sourceAt low enough frequencies, regardless of the intensity of alight source, no electrons are emittedEinstein’s explanation: photonsEnergy of photons are proportional to the frequencies oflight waves

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Quantum Mechanics 2: The Photoelectric Effect

When light is shined on certain metals, energized electronsare emittedPuzzlingly, the number electrons emitted depends only onthe frequency of the light sourceAt low enough frequencies, regardless of the intensity of alight source, no electrons are emittedEinstein’s explanation: photonsEnergy of photons are proportional to the frequencies oflight waves

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Quantum Mechanics 2: The Photoelectric Effect

When light is shined on certain metals, energized electronsare emittedPuzzlingly, the number electrons emitted depends only onthe frequency of the light sourceAt low enough frequencies, regardless of the intensity of alight source, no electrons are emittedEinstein’s explanation: photonsEnergy of photons are proportional to the frequencies oflight waves

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Quantum Mechanics 3: Wave-Particle Duality

Young’s double-slit experimentProbabilistic perspectiveFeynman’s perspective

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Quantum Mechanics 3: Wave-Particle Duality

Young’s double-slit experimentProbabilistic perspectiveFeynman’s perspective

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Quantum Mechanics 3: Wave-Particle Duality

Young’s double-slit experimentProbabilistic perspectiveFeynman’s perspective

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Other Quantum Effects

The Heisenberg Uncertainty PrincipleQuantum foamThe Schrödinger Equation and quantum tunneling

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Other Quantum Effects

The Heisenberg Uncertainty PrincipleQuantum foamThe Schrödinger Equation and quantum tunneling

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Other Quantum Effects

The Heisenberg Uncertainty PrincipleQuantum foamThe Schrödinger Equation and quantum tunneling

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

The Problem of Modern Physics

There are four fundamental physical forces: gravity,electromagnetism, and the strong and weak nuclear forcesGravity is important for large masses, and its behavior isgoverned by general relativityThe other three forces dominate on small scales, and theirbehaviors are explained using quantum mechanicsBut general relativity and quantum mechanics arefundamentally incompatible!Attempting to apply both theories to study massive yet tinyobjects, such as some black holes, yields proposterousresults, such as infinite probabilities

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

The Problem of Modern Physics

There are four fundamental physical forces: gravity,electromagnetism, and the strong and weak nuclear forcesGravity is important for large masses, and its behavior isgoverned by general relativityThe other three forces dominate on small scales, and theirbehaviors are explained using quantum mechanicsBut general relativity and quantum mechanics arefundamentally incompatible!Attempting to apply both theories to study massive yet tinyobjects, such as some black holes, yields proposterousresults, such as infinite probabilities

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

The Problem of Modern Physics

There are four fundamental physical forces: gravity,electromagnetism, and the strong and weak nuclear forcesGravity is important for large masses, and its behavior isgoverned by general relativityThe other three forces dominate on small scales, and theirbehaviors are explained using quantum mechanicsBut general relativity and quantum mechanics arefundamentally incompatible!Attempting to apply both theories to study massive yet tinyobjects, such as some black holes, yields proposterousresults, such as infinite probabilities

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

The Problem of Modern Physics

There are four fundamental physical forces: gravity,electromagnetism, and the strong and weak nuclear forcesGravity is important for large masses, and its behavior isgoverned by general relativityThe other three forces dominate on small scales, and theirbehaviors are explained using quantum mechanicsBut general relativity and quantum mechanics arefundamentally incompatible!Attempting to apply both theories to study massive yet tinyobjects, such as some black holes, yields proposterousresults, such as infinite probabilities

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

The Problem of Modern Physics

There are four fundamental physical forces: gravity,electromagnetism, and the strong and weak nuclear forcesGravity is important for large masses, and its behavior isgoverned by general relativityThe other three forces dominate on small scales, and theirbehaviors are explained using quantum mechanicsBut general relativity and quantum mechanics arefundamentally incompatible!Attempting to apply both theories to study massive yet tinyobjects, such as some black holes, yields proposterousresults, such as infinite probabilities

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Grand Unification Theory

The incompatibility of general relativity and quantummechanics troubled Einstein, but he was unable to resolveit within his lifetimeThe search for a Grand Unification Theory, or “Theory ofEverything", is the major problem of modern physicsString theory is the only theory known at present with thepotential to fit the bill

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Grand Unification Theory

The incompatibility of general relativity and quantummechanics troubled Einstein, but he was unable to resolveit within his lifetimeThe search for a Grand Unification Theory, or “Theory ofEverything", is the major problem of modern physicsString theory is the only theory known at present with thepotential to fit the bill

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Grand Unification Theory

The incompatibility of general relativity and quantummechanics troubled Einstein, but he was unable to resolveit within his lifetimeThe search for a Grand Unification Theory, or “Theory ofEverything", is the major problem of modern physicsString theory is the only theory known at present with thepotential to fit the bill

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Outline

1 Introduction: The Problem of Modern Physics

2 Superstring Theory, M-Theory, and Grand Unification

3 A Stranger World: Some Implications of String Theory

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Superstring Theory

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Building Blocks of Matter

AtomsProtons, Neutrons, and ElectronsQuarksStrings?

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Building Blocks of Matter

AtomsProtons, Neutrons, and ElectronsQuarksStrings?

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Building Blocks of Matter

AtomsProtons, Neutrons, and ElectronsQuarksStrings?

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Building Blocks of Matter

AtomsProtons, Neutrons, and ElectronsQuarksStrings?

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Basic Idea of String Theory

According to string theory, all of the elementary particles(including the muons, gluons, gravitons, and photons) areall manifestations of vibrating loops of stringThe resonance pattern of a string’s vibration determinesthe properties of the resulting particlesThe string, then, is the new “atom"

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Basic Idea of String Theory

According to string theory, all of the elementary particles(including the muons, gluons, gravitons, and photons) areall manifestations of vibrating loops of stringThe resonance pattern of a string’s vibration determinesthe properties of the resulting particlesThe string, then, is the new “atom"

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Basic Idea of String Theory

According to string theory, all of the elementary particles(including the muons, gluons, gravitons, and photons) areall manifestations of vibrating loops of stringThe resonance pattern of a string’s vibration determinesthe properties of the resulting particlesThe string, then, is the new “atom"

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Properties of Strings

Strings are stiffA string is on average of length ≈ 1.62 × 10−35 meters, thePlanck lengthAs the energy of a string increases, it grows

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Properties of Strings

Strings are stiffA string is on average of length ≈ 1.62 × 10−35 meters, thePlanck lengthAs the energy of a string increases, it grows

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Properties of Strings

Strings are stiffA string is on average of length ≈ 1.62 × 10−35 meters, thePlanck lengthAs the energy of a string increases, it grows

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Strings and Grand Unification

Since strings are of about the Planck length, phenomenawhich occur below this scale not only can’t be detected,but don’t have any meaningQuantum foam, the source of the conflict between generalrelativity and quantum mechanics, occurs below this scaleIn effect, string theory “smears out" the region of conflict,and thereby resolves the conflict between the two theories

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Strings and Grand Unification

Since strings are of about the Planck length, phenomenawhich occur below this scale not only can’t be detected,but don’t have any meaningQuantum foam, the source of the conflict between generalrelativity and quantum mechanics, occurs below this scaleIn effect, string theory “smears out" the region of conflict,and thereby resolves the conflict between the two theories

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Strings and Grand Unification

Since strings are of about the Planck length, phenomenawhich occur below this scale not only can’t be detected,but don’t have any meaningQuantum foam, the source of the conflict between generalrelativity and quantum mechanics, occurs below this scaleIn effect, string theory “smears out" the region of conflict,and thereby resolves the conflict between the two theories

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Tests of String Theory

Postdiction: string theory implies gravitySupersymmetry: string theory implies the existence ofsuperpartner particles to all of the existing fundamentalparticlesWith enough energy, strings can grow to macroscopic andeven astronomical size, and can be detected by directinspectionString theory predicts particles of non-half fractionalcharges

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Tests of String Theory

Postdiction: string theory implies gravitySupersymmetry: string theory implies the existence ofsuperpartner particles to all of the existing fundamentalparticlesWith enough energy, strings can grow to macroscopic andeven astronomical size, and can be detected by directinspectionString theory predicts particles of non-half fractionalcharges

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Tests of String Theory

Postdiction: string theory implies gravitySupersymmetry: string theory implies the existence ofsuperpartner particles to all of the existing fundamentalparticlesWith enough energy, strings can grow to macroscopic andeven astronomical size, and can be detected by directinspectionString theory predicts particles of non-half fractionalcharges

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Tests of String Theory

Postdiction: string theory implies gravitySupersymmetry: string theory implies the existence ofsuperpartner particles to all of the existing fundamentalparticlesWith enough energy, strings can grow to macroscopic andeven astronomical size, and can be detected by directinspectionString theory predicts particles of non-half fractionalcharges

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Beyond String Theory: M-Theory

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

M-Theory

There are actually five different versions of string theory,and additional theory called 11d-supergravityThese theories are all dual when considered beneath theumbrella of M-theoryIn M-Theory, there are not only one-dimensional strings,but also two-dimensional membranes, 3-branes, etc.M-Theory is still young, and its properties mysterious

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

M-Theory

There are actually five different versions of string theory,and additional theory called 11d-supergravityThese theories are all dual when considered beneath theumbrella of M-theoryIn M-Theory, there are not only one-dimensional strings,but also two-dimensional membranes, 3-branes, etc.M-Theory is still young, and its properties mysterious

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

M-Theory

There are actually five different versions of string theory,and additional theory called 11d-supergravityThese theories are all dual when considered beneath theumbrella of M-theoryIn M-Theory, there are not only one-dimensional strings,but also two-dimensional membranes, 3-branes, etc.M-Theory is still young, and its properties mysterious

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

M-Theory

There are actually five different versions of string theory,and additional theory called 11d-supergravityThese theories are all dual when considered beneath theumbrella of M-theoryIn M-Theory, there are not only one-dimensional strings,but also two-dimensional membranes, 3-branes, etc.M-Theory is still young, and its properties mysterious

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Outline

1 Introduction: The Problem of Modern Physics

2 Superstring Theory, M-Theory, and Grand Unification

3 A Stranger World: Some Implications of String Theory

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Implications of String Theory

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Implications of String Theory

11-dimensional spacetimeDuality between black holes and elementary particlesSpace-tearing flop transitions and conifold transitionsThe merging of all forcesSpeculation: multiverse theory

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Implications of String Theory

11-dimensional spacetimeDuality between black holes and elementary particlesSpace-tearing flop transitions and conifold transitionsThe merging of all forcesSpeculation: multiverse theory

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Implications of String Theory

11-dimensional spacetimeDuality between black holes and elementary particlesSpace-tearing flop transitions and conifold transitionsThe merging of all forcesSpeculation: multiverse theory

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Implications of String Theory

11-dimensional spacetimeDuality between black holes and elementary particlesSpace-tearing flop transitions and conifold transitionsThe merging of all forcesSpeculation: multiverse theory

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

Implications of String Theory

11-dimensional spacetimeDuality between black holes and elementary particlesSpace-tearing flop transitions and conifold transitionsThe merging of all forcesSpeculation: multiverse theory

Introduction: The Problem of Modern PhysicsSuperstring Theory, M-Theory, and Grand Unification

A Stranger World: Some Implications of String Theory

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