sorry i shoudl have elaborated more , i mean why the speed of light from the half painted mirror to one of the two mirrors is c-v and c+v from the mirror to the painted mirror??
The speed of light in a vacuum is always c. Michelson and Morley erroneously thought that light would travel at c+v if it was moving in the same direction as the aether (which presumably travels at v), and c-v when moving in the opposite direction as the aether.
mmm i have read it you are right in everything but in the speed of c and ether c-v when angle between them is zero and c+v when they are opposite but thank you for all your help