why Lorentz contraction transformation in the direction of motion for the problem in michelson experiment was proposed, instead of length expansion in the direction perpendicular to motion. I think that too will give the same solution. I dont know i might be crazy and silly in this argument. I have read that Professor Feynman has answered this by saying that this violates Newtons Principle of Relativity statement. But i was wondering how this violates. Ok i agree that its obvious that there is no reason to say for expansion in perpendicular direction to motion, but it might contract in direction of motion due to change in length of target by light due to motion. But my doubt is still there is a chance of mistery as like contraction. Ofcourse it would have led to different consequences in other things of relativity. I might have been wrong also, anyway i am not any professional physicst, i m a software engineer and working on physics for now as ameature. working to become a good physicst with clear understanding of nature.