Question

Probably the longest line-of-sight view you can get on or near Earth is from the window of a commercial airplane. Assuming that the resolution of your eyes is limited by the diffraction that occurs as light passes through your pupils, estimate the maximum altitude from which you identify cars on a highway below. In bright light the diameter of your pupils is probably about 3 mm. To get a reasonable estimate we take the length of a car to be on the order of 1 m. (2 km)

Answer 1