Once a joyous celebration of the return of the Sun, or the rebirth of light, Christmas Day and the Winter Solstice have had their respective event dates adjusted over time.
Historians, astronomers, religious scholars, and that vast miscellany of folks who just plain love to celebrate our Sun should find this article by physicist John Perlin of interest, especially at this time of year, when the Winter Solstice draws near.
Perlin, author of Let It Shine: 6,000 Years of Solar Energy, has been kind enough to share his knowledge with CleanTechnica readers.
Christians had for the longest time celebrated the birth of Christ during the first week of January.
But Bishop Liberius of Rome ordered in 354 that all Christians celebrate the birth of the Christ child on December 25. Syrian Christian Bishop Dionysius Salibi writing in the 12th Century explained why: “”It was a custom of the Pagans to celebrate on the same 25 of December the birthday of the Sun, at which they kindled lights in token of the festivity. In these solemnities and revelries the Christians also took part. Accordingly, when the doctors of the Church perceived that the Christians had a leaning to this festival, they took counsel and resolved that the true Nativity should be solemnized on that day.” Their leaders told them they would be celebrating the birth of the true Sun – Sol Iustitiae – the Sun of Righteousness – Christ.
Before the advent of the Gregorian calendar (Julian calendar – 45 BC – was Julius Caesar’s reform of the Roman calendar), the Winter Solstice came on December 25. During several months prior to that date the sun seems to fall lower and lower on the horizon and to spend less time in the sky each succeeding day till it reaches its lowest point and shortest duration on the Winter Solstice, which caused fear and anxiety to the ancients that it had become sick and would soon die.
But then it was reborn after the Solstice, as the days lengthen and the sun rises higher and higher in the sky. Once again the Sun proved invincible to the eyes of its beholders. Just as it always had conquered the evils of darkness each night as a new day dawned, no matter how far it fell the Invincible Sun rose once more. And so for merry-making on December 25, lit up by torches and made joyful by decorations of branches and small trees, the Romans celebrated the “Feast of the Invincible Sun.”
Mr. Perlin is currently contributing a series of articles on photovoltaics. See the first two here:
Gaston Halberghe, The Cult of Sol Invictus, (1977; Leiden: Brill), 174-175. (the only scholarly work existing on this subject)
Bishop Dinoysius Salibi, quoted in Ramsay MacMullin, Christianity and Paganism in the Fourth to the Eighth Centuries, (1997: New Haven and London: Yale University Press), 155.