# EINSTEIN WRESTLING WITH AN UNSOLVABLE PROBLEM

• From: Pentcho Valev <pvalev@xxxxxxxxx>
• Date: Thu, 24 May 2012 20:39:24 -0700 (PDT)

http://www.aip.org/history/einstein/essay-einstein-relativity.htm
John Stachel: "But here he ran into the most blatant-seeming contradiction, which I mentioned earlier when first discussing the two principles. As noted then, the Maxwell-Lorentz equations imply that there exists (at least) one inertial frame in which the speed of light is a constant regardless of the motion of the light source. Einstein's version of the relativity principle (minus the ether) requires that, if this is true for one inertial frame, it must be true for all inertial frames. But this seems to be nonsense. How can it happen that the speed of light relative to an observer cannot be increased or decreased if that observer moves towards or away from a light beam? Einstein states that he wrestled with this problem over a lengthy period of time, to the point of despair."

So "how can it happen that the speed of light relative to an observer cannot be increased or decreased if that observer moves towards or away from a light beam"?

Answer: It simply CANNOT happen. The speed of light "is simply increased by the observer speed, as we can see by jumping into the observer's frame of reference":

http://www.usna.edu/Users/physics/mungan/Scholarship/DopplerEffect.pdf
Carl Mungan: "Consider the case where the observer moves toward the source. In this case, the observer is rushing head-long into the wavefronts... (....) In fact, the wave speed is simply increased by the observer speed, as we can see by jumping into the observer's frame of reference."

http://www.cmmp.ucl.ac.uk/~ahh/teaching/1B24n/lect19.pdf
Tony Harker, University College London: "If the observer moves with a speed Vo away from the source (...), then in a time t the number of waves which reach the observer are those in a distance (c-Vo)t, so the number of waves observed is (c-Vo)t/lambda, giving an observed frequency f'=f((c-Vo)/c) [and an observed speed c'=c-Vo] when the observer is moving away from the source at a speed Vo."

Pentcho Valev
pvalev@xxxxxxxxx
.