During a solar eclipse, the shadows on the ground can change in interesting ways. The crescent-shaped shadows that appear under trees and other objects are due to a "pinhole camera effect," which occurs when light from the eclipse passes through small openings and creates tiny images of the eclipse itself. The shadows can also become sharper and clearer during a solar eclipse due to the reduction of ambient light.

Another phenomenon that can occur during a solar eclipse is the appearance of "shadow bands," which are thin, wavy lines of alternating light and dark that can be seen on the ground just before and after a total solar eclipse. Scientists believe that shadow bands are caused by the turbulent nature of Earths atmosphere, which refracts the thin crescent of sunlight and creates the pattern of light and dark lines. The motion of the air makes them ripple and move, and because the atmosphere is constantly changing, shadow bands are both short-lived and impossible to predict.

In summary, the shadows that occur during a solar eclipse are caused by the pinhole camera effect and the reduction of ambient light. Shadow bands, on the other hand, are caused by the refraction of sunlight through Earths atmosphere and the motion of the air.