In less than a week, people all over the country, including right here at our museum, will be celebrating Halloween. Perhaps your workplaces and schools are already festooned with ghosts, skeletons, graveyards, and the like. If you stop and think about it, you may wonder just how it is that we came to celebrate by trying to disguise ourselves or by trying to frighten people. Is this a trick or a treat?
The short answer as to why we celebrate this time of year with images of death is that we are in the middle of autumn, the season when nature itself is dying. To fully understand why we celebrate Halloween when we do, we must fully understand the seasons.
Earth orbits the Sun with its axis pointed at the North Star, Polaris. As a result, its axis is tilted by about 23.5 degrees with respect to its orbital plane. This tilt, combined with Earth’s revolution around the Sun, causes the seasons. If the North Pole leans towards the Sun, the Sun is higher in our sky and we get more direct sunlight. Also, daytime is longer than nighttime. As the North Pole begins to tilt away fron the Sun, the Sun appears lower and lower across the sky, and daytime gets shorter and shorter. Eventually, the slanted-in solar rays and short days bring about winter. Very cold air masses form in the darkened Arctic and begin to move south, some of which can even reach Houston.
Keep in mind that the Earth’s axis does not tilt back and forth; it points at Polaris the whole time. In June, the North Pole is leaning towards the Sun, but by December, the Earth’s motion has carried it to the other side of the Sun. The North Pole, still tilting the same way, now leans away from the Sun.
A common misconception is that the Earth is closer to the Sun in summer and more distant in winter, and that is what causes our seasons. In fact, Earth’s perihelion (closest approach to the Sun) occurs just after the new year (January 1-4), while aphelion (greatest distance from the Sun) occurs around the 4th of July. Earth’s orbit is an ellipse, but the Earth-Sun distance does not change by enough to affect our seasons.
In the cycle of seasons, there are four points of note. At the March equinox, neither pole is tilted toward the Sun and the Sun is directly overhead at the equator. The is the vernal (spring) equinox for us and the autumnal (fall) equinox for folks south of the equator. At the June solstice, the North Pole is tilted as much as possible towards the Sun, and the Sun is overhead at 23.5 degrees North (the Tropic of Cancer). This is the summer solstice for us and the winter solstice in the Southern Hemisphere. At the September equinox, once again neither pole tilts toward the Sun, and the Sun is again overhead at the equator. This is our fall equinox and their spring equinox. At the December solstice, the North Pole is tilted as much as possible away from the Sun, and the Sun is overhead at 23.5 degrees South (the Tropic of Capricorn). This is the winter solstice for us and the summer solstice below the equator.
We generally think of these points as the beginning of spring, summer, fall, and winter, but it doesn’t have to be that way. After all, nothing magically happens with our weather on these dates. We could just as well consider these points the midpoints of each season. In that case, the seasons would begin and end at points roughly halfway between the equinoxes and solstices, in early February, May, August, and November. If the equinoxes and solstices are ‘quarter days,’ the points halfway between them become the ‘cross-quarter days.’
The ancient Celts of Europe appear to have divided their year in precisely that way. Gauls living in what is now France used a calendar of twelve lunar months with a 13th month added every 2.5 years (similar to the Hebrew calendar today). Their two most significant months were Gamonios (lunar month corresponding to April/May ), which began the summer half of the year, and Samonios (lunar month corresponding to October/November) which began the winter half of the year. Julius Caesar noted that daytime followed nighttime in Celtic days. By extension, the dark (winter) half of the Celtic year preceded the light (summer) half, making Samonios the start of their new year.
The Celts in the British Isles (Irish and Scots) also had festivals aligned with the cross-quarter days. In early February was Imbolc (or St. Brigid’s day). Weather predicting traditions of this day are preserved in our current Groundhog Day. Traditional May Day celebrations are similar to those of the Celtic Beltane. Lughnasadh, in early August, marked the start of the harvest.
The most important, though, was Samhain (pronounced ’sah win’, not ‘Sam Hane’, due to rules of Gaelic spelling), in early November. This three-day festival marked the beginning of the winter half of the year and the start of the whole year, like Gaulish Samonios. It was the close of the harvest opened at Lughnasagh, and the time for culling excess livestock. At this time, the veil between the living and the world of the dead was considered thinner than usual, and people looked forward to meeting and communing with ancestors and relatives who had died. A ‘dumb supper‘ was set aside for departed relatives. To scare away unwanted spirits, people dressed in frightening garb. Note that these spirits were considered unpredictable and possibly mischievous because they were not the familiar ancestors–not because they were particularly evil. Divination was also practiced at this time, as people sought to predict whom they would marry or how many children they would have.
Doing the math, you’ve probably figured out that Halloween is not quite halfway from the equinox (September 22) to the solstice (December 21). But remember, the Celts used a lunar calendar. They celebrated their festivals on a certain phase of the Moon, possibly full moon, occurring nearest the cross-quarter day. Upon the adoption of the Julian calendar, which was not strictly lunar, the festivals were moved to the beginning of February, May, August, and November, although this meant they were no longer exactly on the cross-quarter days.
In the eighth century AD, Pope Gregory III moved the church’s commemoration of the souls in heaven (All Saints’ Day) from May 13 to November 1. Another name for All Saints’ Day is All Hallows Day. (’Hallow’ is an older term for ’sanctify’ or ‘make holy.’ Think of ‘…hallowed be thy name’ from the Lord’s Prayer). The next day became All Souls’ Day. The day before All Hallows Day or All Saints’ Day is All Hallows Eve, or Halloween. The traditions of Samhain, with its similar focus on honoring the dearly departed, were a natural fit for All Hallows Day and All Hallows Eve.
Halloween, then, is ultimately just one expression of the human need to come to terms with death as a natural occurence and to honor those who have gone before. In the season of the fall of the leaf, with the Sun taking a slightly lower path across the sky each day, the natural world is going through its own ‘death,’ providing a perfect context for our own activities. We can therefore think of Halloween itself as a treat, not a trick.
I wish everyone a Happy Halloween, with many more treats than tricks.
This star map shows the Houston sky at 10 p.m. CDT on Sept. 1, 9 p.m. CDT on Sept. 15, and at dusk on Sept. 30. To use the map, put the direction you’re facing at the bottom.
