Thin film Definition and 154 Threads

A thin film of oil (n = 1.26) is located on a smooth, wet pavement. When viewed perpendicular to the pavement, the film appears to be predominantly red (640 nm) and has no component of wavelength 512 nm. How thick is the oil film? I'm getting confused by the use of two wavelengths in this...

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...

Please help: Two rectangular pieces of plane glass are laid one upon the other on a table. A thin strip of paper is placed between them at one edge so that a very thin wedge of air is formed. The plates are illuminated at normal incidence by 546-nm light from a mercury-vapor lamp...

My friend asked me earlier about this homework he had. He said, there's a thin film on a piece of glass, and when you look at it, it looks green. Is this contructive interference? So, I was thinking, This would be kind of an iridesence? Depending on what angle you were looking at the film...