Diffraction Limit:
a) How far away can a human eye distinguish two car headlights 2.0m apart? Consider only diffraction effects and assume an eye pupil diameter of 6 mm and a wavelength of 560 nm.
b) What is the minimum angular separation an eye could resolve when viewing two stars, considering only diffraction effects?
c) In reality, the minimum angular separation is about 1′ of arc. Why is it not equal to your answer in part b)?