ok earth science what is a solstice and why do we have them?
Solstice means "sun standing still", in reference to being at either its highest or lowest possible elevation in the sky at noon each day. It is lowest on Dec. 21-22, when the days are shortest in the northern hemisphere and highest on June 21-22 whcn the days are longest.
The reason we have solstices is that the earth's axis is tilted away from the perpendicular to its orbit. In early summer the north pole points towards the sun and in early winter it points away from the sun (and the sun never rises at the North Pole).