Abstract

This article restudies physical essence of Michelson-Morley experiment, and the result is: 1.Use Einstein?s special relativity to calculate interference experiment, but the result is not consistent with experiment conclusion. 2. Use Galilean principle of relativity to calculate interference experiment, and the result is totally consistent with experiment conclusion. This means that Einstein?s principle of constancy of light velocity loses the evidence. This article challenges relativity, it deserves the readers to read and it has significant physical significance.