In the thought experiment in this paper, we consider inertial frames M and A moving at constant velocity relative to each other. First, a light signal is emitted from inertial frame M toward inertial frame A when the time on a clock in inertial frame M is 1 (s). In the scenario of this paper, that light arrives at inertial frame A when time on the clock in A is 2 (s). Next, the situation is reversed, and a light signal is emitted from inertial frame A toward inertial frame M when the time in inertial frame A is 1 (s). That light arrives at inertial frame M when the time in M is 2 (s). According to the special theory of relativity (STR), the two inertial frames are equivalent, and thus it is not surprising that symmetric experiment results are obtained. However, it has already been pointed out that, among the coordinate systems regarded by Einstein as inertial frames, there are “classically stationary frames” where light propagates isotropically, and “classically moving frames” where light propagates anisotropically. If a classically stationary frame is incorporated into a thought experiment, it becomes easier to predict the experiment results. This paper elucidates a system whereby symmetrical experiment results can be obtained, even if the two coordinate systems are not equivalent. If one attempts to explain such experiment results from the standpoint of the STR, it ironically requires the use of logic that is unacceptable under the STR. Thus, this paper explains those experiment results by using logic different from the STR, and demonstrates the breakdown in the STR.
The Problem of the Twin Paradox Elucidated Based on a Thought Experiment Carried out by Discriminating Between a Classically Stationary Frame and Moving Frame
