1. The problem statement, all variables and given/known data The distance between the movable mirror and the beam splitter in a Michelson interferometer is increased a small amount. What this happens, you see 200 dark fringes move across the field of view. If the incident light was 600nm, by how much was the mirror moved (in millimeters)? 2. Relevant equations I am not sure at all how to begin this problem. I do not think that I can use the equation sin (theta) =m(wavelength)/d because the only variables I know is wavelength. I am not sure what to do with the 200 dark fringes because I do not think that m=200. I also do not know if I could use x =nLw/d because although I think I am solving for L, I do not know x,n, or d. How do I begin?