Sunday’s theme is “It’s not just Christmas,” and it’s appropriate to have this one the day after tomorrow is the winter solstice. In pagan cultures, this is called Yule, hence all those yuletide log things in your Christmas carols.
The idea of celebrations occurring around the solstices and equinoxes is something that has been baked into humanity since the beginning, especially after we went from being nomadic hunters to settlers with agriculture.
It became very important to predict when to plant, when to harvest, when to expect what kind of weather, and the only clocks we had were in the sky — the Sun and the Moon. That’s why we measure days by the Sun and months by the Moon — indeed, in many languages the words for “month” and “Moon” share the same root.
The two most important of the four equinox/solstice times are the one that comes tomorrow, the winter solstice, and the one that comes three months later, the vernal equinox, “vernal” meaning the same thing as spring.
The reason they became so significant is that the Winter solstice is right at the time when the period of daylight in the northern hemisphere is the shortest and the world is dominated by the night. Solstice refers to the idea of a standing or stopping and, indeed, if you look at the analemma of the Sun, you’ll see that the images clump together at the bottom (start of local winter) and the top (start of local summer.)
As for the vernal equinox, this is the day when sunlight and darkness are equal and periods of daylight start to get longer until they hit their maximum on the summer solstice in June.
I think you can see why agricultural societies would find these dates so important. By the start of winter, all of the crops should be in and everything should be stored up to survive the long, cold winter until planting could begin once the ground began to thaw in the spring.
So… they kept an eye out for the day with the least sunlight, then counted thirteen phases of the Moon. This is why so many cultures in the northern hemisphere have big and important holidays, both religious and secular, in late December and late March, and more minor celebrations in late June and late September.
And, to further subdivide it, there are important events in early February (Candlemas or Groundhog Day, anyone?), early May (Beltane/May Day) early August (Lamas Day), and early November (Halloween/All Saints Day).
That was the long way around of saying that it’s totally appropriate for this group of Pagans to be celebrating the solstice at Stonehenge, because the entire structure seems to have been one huge calendar and observatory, lined up so that the way the Sun hit different stones inside let the people know exactly what day it was.
And, ignoring the differences in liturgy and beliefs, isn’t this observation pretty similar to any other religious celebration? People gathered together in a sacred place to sing, connect with each other, and celebrate something beyond to unite them and bring hope.
In this case, these people are actually celebrating the Sun, the Moon, and Mother Earth, and those three things could not be more important to the continued existence of our species and, indeed, every living thing on this planet.