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How Did Einstein Manage To Even Come Up With The Theory Of Special Relativity?

  1. Oct 8, 2012 #1
    I am aware of the motives of finding a modification of Newtonian mechanics, but the effects of relativity are so subtle and negligible. How in the world was he able to even find it? Even at speeds of the Earth orbiting the Sun, the effects are almost negligible. I know he started out with a thought experiment, but it still astounds me. I've read his original papers, but still does not explain how he was able to do it without experimental data. What was his general step by step process in coming up with the theory?
     
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  3. Oct 8, 2012 #2

    ghwellsjr

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  4. Oct 8, 2012 #3

    tom.stoer

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    It was known that Maxwell's theory of electromagnetism does not have Galilei but Lorentz invariance. So the guiding principle was electromagnetism - and Einstein's 1905 paper reads Zur Elektrodynamik bewegter Körper

    http://www.christoph.mettenheim.de/einstein-dynamik.pdf [Broken]
    http://www.fourmilab.ch/etexts/einstein/specrel/www/
     
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  5. Oct 8, 2012 #4
    They originally tried to modify the Maxwell's equations, but they would not be accurate in the trivial cases, so the error was in the mechanics. The question here is how it was feasible to come to such conclusions. Was it just that with the new transformations, the numbers just were consistent? It couldn't have been that simple.
     
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  6. Oct 8, 2012 #5

    tom.stoer

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    It depends whether you believe in Newton or Maxwell ;-)

    Honestly, I do not know enough about the history of relativity to answer these questions
     
  7. Oct 8, 2012 #6

    jtbell

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    It's worth noting that in his work as a patent examiner in Bern, Einstein likely had to review applications for patents on systems for synchronizing clocks at different locations, e.g. stations along a railway line.

    http://www.aip.org/history/einstein/essay-einsteins-time.htm

    And Poincaré, who was one of the two most important precursors to Einstein in relativity theory, along with Lorentz, had also been involved with timekeeping and synchronization technology at the French Bureau of Longitude!
     
    Last edited: Oct 8, 2012
  8. Oct 8, 2012 #7
    Historian Olivier Darrigol has a book called "Electrodynamics from Ampère to Einstein" that seems to give one of the most detailed and complete descriptions of the technical history behind that. You can probably find some of his papers dealing with specific issues freely available on the internet. Much detail is given even to the efforts to interpret or redress the Maxwell equations to allow them to properly function for moving bodies.
     
  9. Oct 8, 2012 #8
    Obviously Michelson–Morley experiment played a great role in the discovery too. Most of the miraculous SR results arise from the Lorentz transformations, which in turn are derived easily using the mere assumptions that light is reference frame independent and that the space must be linear.
     
  10. Oct 8, 2012 #9
    His main inspiration was Maxwell's equations. Ever since Galileo certain symmetries had held in physics, but they didn't hold with Maxwell's equations. I'm sure many people found this quite odd.

    Einstein wrote that he didn't pay much attention to experiments, and even wrote that he didn't know about Michelson-Morley (which is hard to believe). He did know about Fizeau's experments with light and moving water. That was enough. It was basically a philosophical approach, thinking deeply about the assumptions on which physics was based. It took him about ten years, and his wife divorced him for being so obsessed with what looked very much like a weird, useless idea.

    Lorentz -- whom Einstein greatly admired -- came up with the math first, but didn't have the philosophy and didn't realize what the math implied. This is unusual in physics: usually it is the math that matters and the philosophy secondary, but not this time.

    Einstein showed why there was this strange assymetry in Maxwell's equations, and that electric fields and magnetism were really the same thing. It explained Amphere's Law too. The reason the Galilean transforms didn't work was that the electrons were moving about 10% the speed of light, so relativity mattered and was obvious in experimental results.

    The math of special relavitivity is just high school trigonometry. It is the conceptual weirdness that is the barrier. General relativity has even more conceptual weirdness and the math is much harder, so that was even more of an achievement.
     
  11. Oct 8, 2012 #10
    Einstein actually din't invent much. All the mathematics and discoveries were already there. What Einstein did was to dare claiming that Newtonian dynamics is not true. That was something blasphemous at that time, so no one believed in it, despite all the facts were known.
     
  12. Oct 8, 2012 #11
    That's not obvious at all, in fact. Einstein himself said that he was only dimly aware of the MM result at the time.
     
  13. Oct 8, 2012 #12

    Drakkith

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    I think this is a widely popularized myth. The theory was taken with skepticism by most people, which is how all theories should be taken until they have evidence for or against them. That doesn't mean no one believed it despite the facts. There were no facts at that time. It was only after evidence was presented supporting General Relativity that Einstein became well known and the theory started to be accepted. Which is pretty much how it should be. One should never accept a theory that has no evidence supporting it.
     
  14. Oct 8, 2012 #13
    There were clear facts accepted by almost everyone that electrodynamics and Newtonian dynamics are contradictory. That means, using simple laws of logic, that at least one of them is false. The point of disagreement was the rule of relativity of speed. The efforts were contentrated on trying to prove that the standard electrodynamics is false and providing a different theory (i.e. aether theory). No one had guts those days to deny the Newtonian dynamics, which was the true cause of the mess. There were known arguments and observations against Newtonian dynamics: the electrodynamics and all experiments that supported it with violations of standard dynamics. The observations were known since decades. Einstein was the one to link the puzzles together.

    The gravitational lensing of light was an experiment to proove the general relativity. Here we are talking about the special relativity which had beed proven before it was invented.
     
  15. Oct 8, 2012 #14

    Drakkith

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    What experiments were proof enough to validate SR with enough confidence to accept the theory immediately upon publication?
     
  16. Oct 8, 2012 #15
    Yes I know that this is still an open matter and I have no desire to debate his ingenuity. Nevertheless if relativity were to be "rediscovered" Michelson-Morley experiment should be the undisputed starting point.
     
  17. Oct 8, 2012 #16
    I don't quite agree with some of that. Years before Lorentz had begun to imagine that physical lengths might be contracted, Fitzgerald had semi-seriously proposed that notion. And he was a principal "Maxwellian" who was continually in close contact with all other "Maxwellians" and definitely discussed that notion with the others.

    Also, one could posit that, in fact, the Maxwell equations are not at all incompatible with Newtonian dynamics. Helmholtz, Maxwell, Heaviside, Hertz, Cohn and Ritz all came arguably very, very, very close to an interpretation of the Maxwell equations that worked properly between Galilean frames of reference. See Darrigol for details.
     
    Last edited: Oct 8, 2012
  18. Oct 8, 2012 #17
  19. Oct 8, 2012 #18
    Max Planck was quite enthusiastic about special and took the lead in getting it accepted (which wasn't easy). Albert was still in the patent office for a couple more years, then got a job as a lecturer. He also tutored Otto Stern of Stern-Gerlach.
     
  20. Oct 9, 2012 #19
    The Lorentz transformation was actually founded on experimental evidence. You only have to look at Lorentz's 1904 paper:

    http://en.wikisource.org/wiki/Electromagnetic_phenomena

    There he cited four experiments demonstrating the correctness of Maxwell's electrodynamics, the relativity principle, and relativisitic mass/momentum increase

    Michelson and Morley
    Trouton and Noble
    Rayleigh_and_Brace
    Kaufmann's measurements

    Also the Fizeau-Experiment and the Aberration of light were important. Einstein constantly referred to the Fizeau experiment as an important influence for creating relativity, but it is unclear whether he was aware of the other experiments before 1905.
     
    Last edited: Oct 9, 2012
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