The Birth of the Constant-Speed-of-Light Nonsense

Einstein's two postulates sounded perfectly reasonable in 1905. The principle of relativity was fashionable (at least Poincaré firmly believed in it) while the second postulate had been "borrowed" from the dominant ether theory:

Albert Einstein: "...I introduced the principle of the constancy of the velocity of light, which I borrowed from H. A. Lorentz's theory of the stationary luminiferous ether..." https://en.wikipedia.org/wiki/Lorentz_ether_theory

So scientists like Poincaré had to accept Einstein's 1905 postulates. But then, if you accept the premises and obey logic, you cannot oppose conclusions deduced from the premises, even if they sound idiotic. The only option for you is doublethink - a state of mind defined by Orwell in his "1984". That was Poincaré's tragedy:

Olivier Darrigol, The Mystery of the Einstein-Poincaré Connection: "It is clear from the context that Poincaré meant here to apply the postulate [of constancy of the speed of light] only in an ether-bound frame, in which case he could indeed state that it had been "accepted by everybody." In 1900 and in later writings he defined the apparent time of a moving observer in such a way that the velocity of light measured by this observer would be the same as if he were at rest (with respect to the ether). This does not mean, however, that he meant the postulate to apply in any inertial frame. From his point of view, the true velocity of light in a moving frame was not a constant but was given by the Galilean law of addition of velocities." http://www.jstor.org/stable/3653092

George Orwell: "Doublethink means the power of holding two contradictory beliefs in one's mind simultaneously, and accepting both of them."

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