The winter solstice is an interesting mix of science and old tradition, and has been on peoples’ calendars for thousands of years. It may be part of the reason Christmas is celebrated when it is.
So let’s talk astronomy a little. We have the four seasons of the year because the Earth’s axis does not “sit up straight” in its orbit. If it were perpendicular to the sun, we would have no seasons and daily temperatures would be the same year round. Instead, the axis is tilted 23 ½ degrees off of perpendicular, which means as our planet travels around the sun, the north pole leans towards the sun during the summer, and away from the sun during the winter, reaching it maximum lean away on Dec. 22, which is the winter solstice and the official beginning of winter. When the northern hemisphere (that’s us) leans away from the sun, the sun rays striking it is at an angle (less direct), and so its surface does not warm up as much. We actually receive the least amount of heat from the sun on the winter solstice, and so you would think it would be the coldest day of the year. But the Earth’s atmosphere moderates the heating and cooling of the planet, causing temperature fluctuations to lag by several weeks, so the effects of the solstice cool down won’t show up until January.
Solstice is from the Latin word solstitium, which means “the sun stands still.” During either the winter or summer solstice the day/night cycle is growing neither longer nor shorter, but sort of pausing a very short while. Observable events around the winter solstice are late dawns, early sunsets, and the low arc of the sun across the southern sky each day. Also your shadow is at its longest this time of year.
Long ago people had a lot riding on the progression of the seasons. Starvation was a real possibility during the winter months, which were often referred to as “famine months.” So it was very heartening to see the days begin to get longer after the winter solstice, giving hope that food growing weather would return. It was so important that festivals were observed to celebrate the solstice. Livestock was often slaughtered around this time so they wouldn’t have to be fed during the coldest months, so it was a time of plentiful fresh meat. Also, the production of wine and beer finished its fermentation process around this time, so with plenty of food and drink, why not party I guess. In Rome they had a festival was called Saturnalia in honor the god Saturn. In Scandinavia they had the Feast of Juul (pronounced yule), a celebration involving a lot of bonfires. These festivals predated Christianity and were considered pagan, and there is a thought that celebrating Christmas near the winter solstice was fortuitous in helping shift celebrating pagan rituals (especially in Rome) to celebrating the birth of Christ.
Whatever the reason, Dec. 25 is a worthy celebration of a pivotal event in history, so remember the reason for the season. And the winter solstice on Dec. 22 (at 11:48 p.m.) is a good time to reflect on the blessings of having four seasons to enjoy throughout the year. May the peace of Christmas be upon you all.
Steve Roark is the area forester in Tazewell, Tennessee for the Tennessee Department of Agriculture, Forestry Division.