Winter Solstice

(This is as a result of a challenge from marijayn at onelongminute.com)

My brain has only made one connection with Winter Solstice in the last two weeks since the challenge was posted. And that is that the page on my pc remains as clean and white as a winter solstice snowdrift.

Perhaps it could have something to do with the fact that the only thing I know about the winter solstice is that it happens on 21 June? And that it is the shortest day/longest night of the year? Oh, and that there is some vague, other-worldly connotation?

I realised that before I could write anything remotely coherent, I’d need to redirect the brain cells away from mojitos and sushi, and towards astrophysicostronomy type stuff.

And this is what I found:

 Photo: Astronomy Picture of the Day

 
At the solstices (summer and winter), the sun reaches its extreme northern and southern points in its ecliptic, and appears to stand still (Lat. sol, sun; sistit, stands) before it turns back on its apparent course.  In the Northern hemisphere, the summer solstice, when the sun is in the zenith* at the tropic of Cancer, occurs about June 21 or 22; and the winter solstice, the shortest day, when it is over the tropic of Capricorn, occurs about December 21 or 22.  The solstices are reversed in the Southern hemisphere**

The solstices should not be confused with the darkest day or night, or the day with the earliest sunset or latest sunrise.  (Sounds like the debate about where the Atlantic and Pacific meet – Cape Point, or Cape Agulhas?) The actual winter solstice only lasts an instant, but the term is also used to refer to the full 24-hour period.

Initially, in 45 BCE***, Julius Caesar set the winter solstice at 25 December (Christ’s birth was apparently in September, but moved by the powers that be to 25 December, to coincide with the Pagan celebration Deus Sol Invictus****; in the belief that this would popularise Christianity.  But I digress…)

At that time, the difference between the calendar year (365.2500 days) and the tropical year (365.2422 days) moved the day associated with the actual astronomical solstice forward approximately three days every four centuries.  Picky picky.  In 1582, Pope Gregory XIII reckoned that Jules had been smoking his laurels, so he changed the rules, bringing the northern winter solstice to around December 21.  Nowadays, Greg’s calendar has the solstice still wandering around a bit, but only about one day per 3000 years. (The error shifts by about 1/4 day per year, and is corrected by a leap year every 4th year.  With exceptions, of course.*****)

On the night of the winter solstice (as seen from a northern sky) the three stars in Orion’s Belt align with Sirius, the brightest star in the eastern sky,  to show where the Sun will rise in the morning after winter solstice.  On winter solstice, the Sun ceases to decline in the sky and the length of daylight reaches its minimum for three days, during which the sun does not move on the horizon. After such a time, the sun begins its ascent into the northern sky and days grow longer. Hence the interpretation by many cultures of a sun reborn and a return to light.

This can be seen in the layouts of late Neolithic and Bronze Age archaeological sites like Stonehenge in Britain and Brú na Bóinne (New Grange) in Ireland (which is older than Stonehenge and the pyramids).

Newgrange in Ireland. Photo: Candlegrove.

The primary axes of both of these monuments appear to have been carefully aligned on a sight-line framing the winter solstice sunrise (New Grange) and the winter solstice sunset (Stonehenge).

Solstice sunrise at Newgrange

The winter solstice appears to have been immensely important to communities who were not sure whether they could survive the winter, and had to prepare during the previous nine months. Starvation was common in winter between January and April. In temperate climates, the midwinter festival was the last feast celebration before deep winter began. Most cattle were slaughtered so they would not have to be fed during the winter. Midwinter was therefore one of the only times of the year when a supply of fresh meat was available. Also, the majority of wine and beer made during the year was finally fermented and ready for drinking at this time.

Even nowadays, these gatherings are still valued for emotional comfort, giving people something to look forward to at the darkest time of the year. The depressive psychological effects of winter are mainly tied to coldness, tiredness, malaise and inactivity. Winter weather, plus being indoors, causes negative-ion deficiency which decreases serotonin levels, in turn resulting in depression and tiredness. Midwinter solstice festivals and celebrations often call for evergreens, bright illumination, large ongoing fires, feasting, communion with close ones; and dancing and singing are examples of cultural winter therapies that have evolved as traditions since the beginnings of civilization. These traditions stir the wit, stave off malaise, reset the internal clock and rekindle the human spirit.

So bloggers, when’s the party?

OK, now that I know everything that I need to know about the solstices, I can write something for the challenge. Oh dear.  I’ve used up my 1000-word quota already. Blabbermouth.

.o0o.

*zenith.  Nice word.  Rolls off the tongue.  When last did you hear someone use zenith in daily speech?  Like apex.  Or trapezium.  Aw, shuddup already.  Oh yes, its definition:  The point on the celestial sphere that is directly above the observer, or, the hightest point above the oberver’s horizon attained by a celestial body.  I feel my eyes glazing over, so I’ll stop now.

** I tried to work out which tropic the sun zenithed at in the Southern hemisphere in winter.  But I got flummoxed and just copied what the book says.  So sue me.

***BCE:  Before Common Era.  A neat compromise for the various cultural dating systems in the world.  Nothing to do with Dating Buzz.

**** Deus Sol Invictus (The undefeated sun god) Festivals celebrating the birth of the Unconquered Sun (the “rebirth” of the sun)

***** (a five-star explanation follows) There is a leap year in every year divisible by four; except for years which are both divisible by 100 and not divisible by 400. Therefore, the year 2000 was a leap year, but the years 1700, 1800, and 1900 were not.

.o0o.

Sources:

Brewer’s Dictionary of Phrase and Fable
Reader’s Digest Universal Dictionary
Wikipedia, and other bits of the interweb (referenced above)