The picture above shows light from a narrow laser beam as it appears on a screen after passing through TWO narrow slits. Examine the pattern and answer the following questions.
What is the distance between two successiva minima due to interference between the slits?
What is the distance between two successiva minima due to diffraction at the slits themselves?
What would change if the separation between the slits were reduced?
What would change if each slit was made wider?

The picture on the left shows what happens to a narrow laser beam after it passes through a small, round pinhole. The same happens to light passing through your pupil. In your texbook, find the criterion for resolving two light sources. Use the criterion to estimate at what minimum distance your eye would be able to resolve the two headlights of an aproaching car. (Estimate the diameter of your pupil to be 2 mm.)
Hint: Look at Example 24.3

Why does a soap bubble reflect virtually no light just before it bursts?

Rock specimen slices are often 30 micrometers thick. approximately how many wavelengths of visible light does that represent? What additional information would you need to be able to answer this question exactly?