This week I am learning about shadows.  Shadows are formed when a solid object is in the way of light.  An object where no light can pass through is called an opaque object.  The easiest example is our body.  Whenever light is not able to go through an object, it creates a dark area around the object. This patch where the light can not reach is called a shadow. Duh.  Opaque objects create clear dark shadows.  Shadows change size because the angle of light at which the light is falling on the object.  Is it longest in the early morning and the late afternoon? At noon, when the sun is overhead there is little or no shadow at all. Why?  The position of the sun changes throughout the day, thus changing the angle at which the rays fall on the ground.  A long time ago people tracked the length of shadows throughout the day to keep track of time. The world’s earliest clock was a sun dial.