A student diving in a swimming pool (filled with water with index of refraction 1.33) creates thin films of air. Viewed underwater, what are the first two non-zero thicknesses of an air film for which there will be constructive interference for reflection off the surfaces of the bubble for light of wavelength 655 nm in water a. 123 nm, 369 nm b. 218 nm, 653 nm c. 218 nm, 873 nm d. 246 nm, 492 nm e. 436 nm, 871 nm f. 436 nm, 1091 nm The answer is B, but I keep getting D. Here is what I have done: Lambda=2nd/m (m=1,2,3..,n=index,d=thickness) d=Lambda(m)/2n=246nm=WRONG! Need help please. Thanks in advance.