Recent content by stpmphysics

Thanks a lot ehild, what's the coherent length of the light?

When the thickness of the oil increases, the path difference increases. Isn't that now the interference pattern(bright and dark fringe) are spread over a larger area and the fringe distance subsequently increases?

yeah why the fringes get closer?

Thanks for all your replies.

Thanks again, so here the path difference, \triangle L=2 \mu t+\frac{1}{2}\lambda It's either it equals m\lambda for constructive or (m-0.5)\lambda for destructive. How did you know its destructive ?

Thanks Delzac. Why do the light rays become more destructive when their optical path difference increases?

Homework Statement Hi all, i have a question on thin film interference. Lets say there is an oil drop on the surface of water. Light reflected from the oil drop is observed from above. Explain why interference fringes are not seen when the thickness of the oil drop increases...