The winter solstice is approaching and falls on the 21st of December in the Northern Hemisphere. It is reversed in the Southern Hemisphere where the 21st of December marks the summer solstice, the longest day of the year. Why are these days significant, and what do they mean?
The reason there are solstices in the first place has to do with the way the earth is aligned in its orbit. Our planet is tilted at an angle of 23.5 degrees in relation to the orbit of the sun. This produces seasons, varying lengths of the day, and determines the height of the sun in the sky.
Ancient astronomers noticed that if one marked the position of the sun at the same time each day, the pattern created formed a figure resembling an eight, called today an analemma. How the analemma is aligned (whether up and down or tilted sideways and by how much) is determined by one’s location on the Earth’s surface. At the equator, the analemma looks like an infinity sign.
The pattern is shaped like an eight because the Earth’s orbit is an ellipse, not a circle. At the farthest point from the sun, the Earth moves slowest; while at closest approach, it moves fastest. These two points occur near the solstices. The bulges of the analemma are created by the gradually changing orbital speeds as the Earth approaches these two extremes.
Ancient standing stones were often aligned such that the sun would illuminate certain markings at the longest and shortest days of the year. The winter solstice had major significance because from that day forward, the sun would shine longer, signifying that winter would eventually come to an end. I imagine that was not only hopeful, but joyous news and made the rest of the winter bearable as a result. Perhaps that’s why Christmas is celebrated shortly thereafter. It’s good news, after all.