Question: in experiments with his interferometer michelson found that the red...
In experiments with his interferometer, Michelson found that the red cadmium line at λ=643.8nm produced fringes until one of the arms of the interferometer was moved 25cm from initially being at the coincidence or equal path length position.
a. How many fringes moved through the field of view?
b. What is the approximate coherence time of the light?