kidzsearch.com > wiki   Explore:images videos games  

Shadow




KidzSearch Safe Wikipedia for Kids.
Jump to: navigation, search
Shadow of a cactus on a wall
Three moons (Callisto, Europa and Io) and their shadows parade across Jupiter

A shadow is a dark area on a bright surface. It is caused by something blocking a source of light. A shadow's outline, called a silhouette, will have the same shape as the object blocking the light.

Depending on the light source, or sources, a wide range of effects can be produced. A point source of light casts only a simple shadow, called an "umbra". A "penumbra" is the region in which only a portion of the light source may be blocked. If there is more than one light source, there will be several shadows, with the overlapping parts darker, and various combinations of brightness or even colors. The more diffuse the lighting is, the softer and more indistinct the shadow outlines become, until they disappear. The lighting of an overcast sky produces few visible shadows,

Astronomical shadows are usually sharp. This is because in space the light usually does not go through an atmosphere.



Help Improve This Page: Please contact us to become an approved KidzSearch editor and provide your credentials. You can also give immediate feedback in our Wiki Feedback Forum.