Volume 18: Pages 541-546, 2005
Photon Round-Trip Times and the Equivalence Principle
Department of Mathematics, Tufts University, 503 Boston Avenue, Medford, Massachusetts 02155 U.S.A.
Where there is no gravity, I consider a linearly accelerating frame in which the proper acceleration at each spatial point does not vary with time and the proper acceleration is the same throughout the spatial coordinates. Then I consider the round‐trip time for a photon between two given spatial coordinate points. The theory of general relativity predicts that the trip time is a constant with respect to time. Contrary to this prediction, I analyze the motion of the photon in an inertial frame and show a discrepancy of order a τ/c, where a is the proper acceleration; τ is the photon round‐trip time in the accelerating frame, which also indicates the spatial size of the accelerating frame; and c is the speed of light.
Keywords: equivalence principle, relativity, special relativity, space‐time coordinate system, proper time, linear acceleration, proper acceleration, clock hypothesis
Received: April 15, 2005; Published online: December 15, 2008