Determination of the velocity of an opaque body moving uniformly by measurements inside it

Abstract

In this paper we show how the velocity of a moving uniform opaque body can be calculated without external references. This is done with the help of photodetectors, which measure the time of arrival of light from a point source to fixed equal distances inside the body. The calculation of the body’s velocity is based on the postulates of the special theory of relativity that space is homogeneous, isotropic and the speed of light in vacuum is an invariant constant with a certain value independent of the velocity of the radiation source.