1. The problem statement, all variables and given/known data Light of wavelength 640 nm in water illuminates a glass (n = 1.5) wedge submerged in water (n = 1.33). If the distance between successive bright fringes is 6mm. Find a) the change in thickness of the glass between these fringes and b) the angle of the wedge 2. Relevant equations 3. The attempt at a solution Since it's a bright fringe and n=1 to n=1.5 to n=1.33, it's constructive so 2t= (m+1/2)lambda/nfilm. WHen i plug in the values i get t=(m+1/2)(6.40X10^-7 m)/2(2.5) but i'm not sure how i can find m with the distance between the bright fringes (y=6X10^-3 m)... And for the angle of the wedge i thought that it would be pi since n=1 to n=1.5 to n=1.33.