What is the winter solstice, and why does it occur? Simply put, because of the Earth’s tilt, the sun makes its lowest arc across the sky. Therefore, the northern hemisphere gets its least amount of direct sunlight of all days of the year. It is the first official day of winter; astronomically it’s marked this year on December 22 at 1:08 a.m. EST.
The winter solstice marks the shortest day and the longest night of the year. The sun appears at its lowest point in the sky, and its noontime elevation appears to be the same for several days before and after the solstice. Hence the origin of the word solstice, which comes from Latin solstitium, from sol, “sun” and -stitium, “a stoppage.” Following the winter solstice, the days begin to grow longer and the nights shorter.
Norsemen were among the earlier civilizations who feared the day the sun hung so low in the sky because they thought it wouldn’t come back. Those early folk lighted bonfires and shed blood to coax the return of warmth and light.
You can read more about this remarkable event at http://www.cleveland.com/living/plaindealer/index.ssf?/base/living-1/1198143063305810.xml&coll=2 or http://www.cbc.ca/news/background/forcesofnature/winter-solstice.html .