How the Sun seemingly moves across the sky... 

     The sun appears to move because the Earth is rotating: as our planet spins on its axis, the sun's position in the sky appears to move. When the sun is directly overhead, it means that your position on the Earth is directly facing the sun. When it is night, it means the Earth has rotated so that the sun is now behind you.

     A basic experiment using only a telescope with the necessary solar protection can reveal many aspects of the sun and its movement across the sky. See here and find out why.