Suppose we place a chamber 10.0cm long with flat parallel windows in one arm of a Michelson Interferometer that is being illuminated by 600-nm light. If the refractive index of air is 1.00029 and all the air is pumped out of the cell, how many fringe-pairs will shift by in the process? for this problem, i can't visualize the design of the interferometer at all. All i'm thinking is that m=finge-pairs?, so m=2xn/λo = 333430??? Any help would be good...at least let me know if i'm going to the right direction or not.