AP Photo

Throughout history, luminaries ranging from Aristotle to Sir John Herschel have reported that stars are visible during the day from the bottoms of mine shafts, tall chimneys, coal pits or cisterns. Folk tales have also told of people spying celestial pinpricks of light reflected in the bottoms of dark lakes or wells. Presumably, the ability to see stars under such conditions was thanks to a mineshaft’s smaller visual angle, or to the greater contrast provided by dark surroundings.