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Pentcho Valev

Posts: 6,212
Registered: 12/13/04
Posted: Mar 8, 2013 3:18 AM
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The Elegant Universe, Brian Greene, p. 19: "Following the reasoning based on the traditional Newtonian worldview, since you are now speeding away, you would expect to measure a slower speed for the oncoming photons. Specifically, you would expect to find them approaching you at (670 million miles per hour - 100 million miles per hour =) 570 million miles per hour. Mounting evidence from a variety of experiments dating back as far as the 1880s, as well as careful analysis and interpretation of Maxwell's electromagnetic theory of light, slowly convinced the scientific community that, in fact, this is not what you will see. Even though you are retreating, you will still measure the speed of the approaching photons as 670 million miles per hour, not a bit less."

Brian Greene elaborates on his lies: "If Maxwell's equations did not refer to a standard of rest, then there was no need for a standard of rest. Light's speed, Einstein forcefully declared, is 300,000 kilometres per second relative to anything":
Trouble with physics: The roots of reality, Brian Greene: "In the late 1800s, when James Clerk Maxwell realised that light was an electromagnetic wave, his equations showed that light's speed should be about 300,000 kilometres per second. This was close to the value experimenters had measured, but Maxwell's equations left a nagging loose end: 300,000 kilometres per second relative to what? At first, scientists pursued the makeshift resolution that an invisible substance permeating space, the "aether", provided this unseen standard of rest. It was Einstein who in the early 20th century argued that scientists needed to take Maxwell's equations more seriously. If Maxwell's equations did not refer to a standard of rest, then there was no need for a standard of rest. Light's speed, Einstein forcefully declared, is 300,000 kilometres per second relative to anything. The details are of historical interest, but I'm describing this episode for a larger point: everyone had access to Maxwell's mathematics, but it took the genius of Einstein to embrace it fully. His assumption of light's absolute speed allowed him to break through first to the special theory of relativity ? overturning centuries of thought regarding space, time, matter and energy ? and eventually to the general theory of relativity, the theory of gravity that is still the basis for our working model of the cosmos."

Of course, Maxwell's equations did refer to a standard at rest - his electromagnetic theory predicted that an observer in a frame of reference moving with speed v relative to the frame at rest would measure the speed of light to be c'=c+v:
Gabrielle Bonnet, École Normale Supérieure de Lyon: "Les équations de Maxwell font en particulier intervenir une constante, c, qui est la vitesse de la lumière dans le vide. Par un changement de référentiel classique, si c est la vitesse de la lumière dans le vide dans un premier référentiel, et si on se place désormais dans un nouveau référentiel en translation par rapport au premier à la vitesse constante v, la lumière devrait désormais aller à la vitesse c-v si elle se déplace dans la direction et le sens de v, et à la vitesse c+v si elle se déplace dans le sens contraire."
John Norton: "That [Maxwell's] theory allows light to slow and be frozen in the frame of reference of a sufficiently rapidly moving observer."
Stephen Hawking: "Maxwell's theory predicted that radio or light waves should travel at a certain fixed speed. But Newton's theory had got rid of the idea of absolute rest, so if light was supposed to travel at a fixed speed, one would have to say what that fixed speed was to be measured relative to. It was therefore suggested that there was a substance called the "ether" that was present everywhere, even in "empty" space. Light waves should travel through the ether as sound waves travel through air, and their speed should therefore be relative to the ether. Different observers, moving relative to the ether, would see light coming toward them at different speeds, but light's speed relative to the ether would remain fixed."

Pentcho Valev

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