1. The problem statement, all variables and given/known data A shift of one fringe in the Michelson-morley experiment would result from a difference of one wavelength or a change of one period of vibration in the round trip travel of the light when the interferometer is rotated by 90 degrees. What speed would the Michelson have computed for Earth's motion through the ether had the experiment seen a shift of one fringe? 2. Relevant equations delta(t)=(L*v^2)/(c^3) 3. The attempt at a solution delta=(L*v^2)/(c^3) => v=sqrt((c^3*delta(t))/(L)) , where L is the length of the wavelength andd c is the speed of light. I don't understand how shifting the fringe would effect the velocity. My professor says I'm have the right equation for finding the velocitiy of the Earth's motion, But he says the velocity is also related to the fringe where the fringe is represented by light over one period per wavelenght and light oscillates over that period.