Today, December 21 is Winter Solstice. The shortest day and longest night of the year. This day opens the winter season...officially because it is the first day of winter. The earth is actually closer to the sun now than at any time in its orbit but the sun is also (in the Northern Hemisphere) at it's southernmost point in relation to the earth. Because of this, it make a brief trip above the horizon and then dips down again, giving us our long winter night.
Visit the U.S. Naval Observatory's Web site here to find out a more complete scientific explanation.
This is the night our northern ancestors would bundle up, and light the Yule log to ward off the coming dark days of winter. Yule celebrations lasted as long as the Yule log burned - anywhere from three to twelve days - a definite incentive for a BIG log. The Germanic peoples celebrated Yule with feasting and gift giving. In pagan traditions this holiday is celebrated as the rebirth of the Great God, who is viewed as the newborn solstice sun. Of course this tied in nicely to Christian traditions for December 25 in order to convert the pagan peoples to Christianity in the Middle Ages.
In fact, most cultures throughout history have some traditions in honor of this day. So tonight as the sun dips below the horizon, burn a Yule log to stave off the darkness. Light candles to welcome the sun's rebirth, for from this day forward the days grow longer again.
Joyous Yule and Happy Midwinter to one and all!