# Michelson-Morley meets Quantum Mechanics

The Michelson-Morley experiment (read the original paper here) is one of the first textbook experiments that you learn about in support of the light postulate. From this postulate, together with the principle of relativity, it is easy to derive the group of Lorentz transformations, which form the basis for special relativity theory. (Honesty note: some more mild-mannered principles are also required for this derivation, such as the homogeneity and isotropy of space.)Of course, it is possible to derive the Lorentz transformations without the light postulate (Torretti 1983, ch. 3). And famously, historian Gerald Holton revealed in an interview that Einstein was not influenced by this experiment when developing the theory of special relativity. (What experiments did influence him still remain a mystery, at least to me).