quiz question what is it that is “equivalent” in the equivalence principle of general...
TRANSCRIPT
Quiz QuestionWhat is it that is “equivalent” in the equivalence principle of general relativity?
A. Light and matterB. Light and energyC. Velocity and rotationD. Gravity and accelerationE. Momentum and energy divided by c
Where does E=mc2 come from?
Where does E=mc2 come from?
Where does E=mc2 come from?
Hydrogen atoms consist of one electron which is bound to a proton by electromagnetic forces. If I very carefully weigh a hydrogen atom, what will I get?
A : The mass of an electron plus the mass of a proton
B : Something a little BIGGER than (A)C : Something a little SMALLER than (A)D : Something entirely different from (A)E : A star on my forehead
A nuclear power plant generates 10 million Watts of power nonstop for a day. How much less do the fuel rods weigh at the end of the day?
A : around 0.000001 gramsB : around 0.01 gramsC : around 1 gramD : around 1 kgE : around 100 kg
GETTYSBURG ADDRESSFour score and seven years ago our fathers brought forth on this continent, a new nation, conceived in Liberty, and dedicated to the proposition that all men are created equal.
Now we are engaged in a great civil war, testing whether that nation, or any nation so conceived and so dedicated, can long endure. We are met on a great battle-field of that war. We have come to dedicate a portion of that field, as a final resting place for those who here gave their lives that that nation might live. It is altogether fitting and proper that we should do this.
GETTYSBURG ADDRESSBut, in a larger sense, we can not dedicate -- we can not consecrate -- we can not hallow -- this ground. The brave men, living and dead, who struggled here, have consecrated it, far above our poor power to add or detract. The world will little note, nor long remember what we say here, but it can never forget what they did here. It is for us the living, rather, to be dedicated here to the unfinished work which they who fought here have thus far so nobly advanced.
GETTYSBURG ADDRESSIt is rather for us to be here dedicated to the great task remaining before us -- that from these honored dead we take increased devotion to that cause for which they gave the last full measure of devotion -- that we here highly resolve that these dead shall not have died in vain -- that this nation, under God, shall have a new birth of freedom -- and that government of the people, by the people, for the people, shall not perish from the earth.
-- Abraham Lincoln, November 19, 1863
Energy of a moving object
20 mcEEE k
ump
Kinetic Energy vs. Velocity
At the electron accelerator in Cambridge, Mass., the final
acceleration stage has the following characteristics:
This increase in velocity requires a 186x increase in energy, yet only saves one second off a two hour journey.
Feed electrons Electrons out
Velocity 0.99986 c 0.999999996 c
Relativistic Mass 60 m0 11,180 m0
Relative time for auto trip 2 hr 1 hr 59 min 59 sec
Electron Volts
1 eV=1.60217733×10− 19 J
General Relativity – add another postulate
Equivalence Principle
© Dallin S. Durfee
If the scientist on the accelerating spaceship is not in an inertial frame, neither is the scientist on Earth!
So how can I do an experiment in a truly inertial frame if I happen to live on earth?
Equivalence PrincipleThere is no way to tell if we are on Earth, or on an accelerating space ship
F=ma
© Dallin S. Durfee
Freefalling Frames...
© Dallin S. Durfee
Gravitational Redshift
© Dallin S. Durfee
© Dallin S. Durfee
Formulation of Gravitational Redshift
dg
Deflection of Light
© Dallin S. Durfee
Deflection of Light
Light “falls” at the same rate as everything else. This is because things don’t really “fall” under gravity, they just follow their non-accelerating world line.
© Dallin S. Durfee
Shift in the Perihelion of Mercury
An electron with a velocity of 0.5 c
An electron with a kinetic energy equal to its rest
energy
An electron and a positron annihilate
𝑚e=0.51099906 MeV /𝑐2
