Abstract

It is quite uncontroversial that there exists a vast array of experiments which support Einstein theory; references can be found in any textbook and numerous review articles. However, an important question that is rarely addressed, and then inadequately, is whether the cited experiment uniquely supports Einstein theory. For example, the equation E = mc² for which Einstein is known even to the man in the street, can be derived -- as was done by Einstein himself -- from purely classical physics, without any reference to four-dimensional "spacetime" coordinates or to a purely classical physics, without any reference to four-dimensional "spacetime" coordinates or to a constant light velocity.  It follows that an experiment -- or a million experiments -- which confirm E = mc² thus support classical physics just as well as Einstein theory.  This paper addresses the question of what experiments are required to support uniquely Einsteinian relativity theory.