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You have the light speed thing backwards. People had already had a fair amount of evidence that the speed of light was constant, it's just one of those things that's hard to accept / build a reasonable model for why that might be the case. Think of it as an open question if the experiments where inaccurate or the universe was just strange. Until relatively came along and said, assume the speed of light is constant what would that mean?

1849: http://en.wikipedia.org/wiki/Fizeau%E2%80%93Foucault_apparat... "Fizeau's value for light's speed was about 5% too high." which is not that bad for a first stab. And good enough to show that water slowed the speed of light vs speeding it up.

vs 1900 to 1905: http://en.wikipedia.org/wiki/Special_relativity




The genius leap (from which special relativity is derived) is the postulate that it's constant for regardless of the state of motion. The older research mentions nothing of the sort.


No, there had already been some experiments that should have been accurate enough to detect the orbital motion of the earth and it's effect on the speed of light.

Google '1890 speed of light experiments' and you should get Modern Physics for Scientists and Engineers page 21 - 27. It talks about the interferometer experiments that suggested the speed of light was constant. http://en.wikipedia.org/wiki/Interferometry


I don't think anybody had postulated the invariance of the speed of light before Einstein (except perhaps the ballistic theory). The michelson-morley and related experiments were interpreted as a "failure to detect the motion of aether", not as proof for light speed invariance. What's more, we now know that the michelson-morley result is was not even what motivated einstein, but it was one of the first results explained by his theory. http://en.wikipedia.org/wiki/Michelson-Morley_experiment


As a fleshed out theory, no. There is no privileged frame of reference in Newtonian mechanics, so that's not exactly a new idea. People had been measuring the speed of light for a while, so light having speed X and no privileged frame of reference is no great leap over the 50+ years they had been measuring the speed of light it had probably occurred to thousands of people as one of the possibility's. The aether idea and ballistic theory where a few of the many possibility's being considered back then.

Anyway, what Einstein did was deeper than just saying the speed of light was constant and there are no privileged frames of reference. Einstein got the math in all it's glory to work out.




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