If you stand at the bottom of a well and look up at the entrance is it possible to see stars in daylight?

Asked by: James U'Dell

However, the light from planets and even a few stars is bright enough to occasionally be detected during the day. So the answer to your question is yes, but realize that this is not some special property of wells, but just something which is occasionally possible anytime you limit the amount of light obliquely reaching the retina. Note that this detection of faint light sources is most difficult when light hits the fovea, which occurs when you look directly at something. Thus attempts to view faint light sources often results in a frustrating sense of catching a glimpse of the source in the peripheral vision, only to have it "disappear" when you try to look right at it.

Answered by: Rob Landolfi, Science Teacher, Washington, DC