Why 25?

Pondering about the origins of Christmas and meanings that people give to events, while waiting for the New Year.

Join us in Wairarapa
for stargazing

Or, be an armchair astronomer

If you can’t make it to Wairarapa or New Zealand,  learn astronomy online with us and SLOOH. 

Love this photo? Take your own!

Also check out our favourite astrophotography guide

Learn from 
award-winning photographer Alex Conu

In the year 336, Flavius Valerius Aurelius Constantinus, better known as Constantine I or Constantine the Great declared that 25th of December will be observed as the day when Jesus Christ was born.

There is a lot of speculation about the exact date of the birth of Jesus Christ, which is hard to back up with proof. That is, we don’t really know neither the day nor the year, but we do know that a few very important pagan traditional festivals were celebrated around 25th of December before Christ was even born.

Saturnalia and other solstice festivals

One of them was called Saturnalia and it was held in the honour of Saturn, the God of Agriculture and many other things, such as destruction, liberation, periodic renewal (similar jobs as the ones held by the older god Moksha, from the Sanskrit tradition). Saturnalia took place roughly from 17 to 23 of December. This very famous Roman festival was celebrating time, just like we do today at the end of the year, when we look back to what we did and we look forward to what we want to do.

a3d1e20f742d9fd4fb7f2051aef07169
Janus Bifrons, Hermitage Museum

Janus Bifrons: In fact, the Romans and the Thracians had a designated god for looking both in the past and in the future. He is actually my favourite god – if you can have one. Janus Bifrons (which literally means two foreheads), was the god of gates, spatiality, doorways, passages and also of time, the one who gives January its name. More about him, in January when is really cold at mid latitudes in the Northern Hemisphere. December was however the month of mischief: the festival of Saturnalia was well known for role reversals, free speech, gift-giving and revelry.

Another festival called Dies Natalis Solis Invicti, the days of the birth of the invincible Sun is also controversial, some attributing it to the birth of Mithras, the Persian god of light, started on 25 of December and  lasting through January 1st.

Maybe the story of Christmas originated before the time when people built sanctuaries to help them measure time. Imagine life in the Central and Northern Europe anytime between 2-11,000 years ago. It was very cold in winter. Temperatures were dropping to negative values, snow was covering everything and the worst season to survive through was wintertime. The Moon would have been an unreliable marker to tell the seasons, even though the Moon must have been humankind’s first timekeeper. And when your survival depends on it, probably you get to be the best stargazer ever.

It could have been that people looked at the Sun to mark the approximate middle of wintertime.

Why the middle of wintertime and why not the middle of summertime, or both? I believe it had to do with survival. Winter covered those parts of the world by a thick blanket of snow; winter was the time when people relied on food gathered in autumn, and supplemented it with animal proteins, which would help them survive the cold. So I believe they sought to measure winter solstice to understand how to provision food. You don’t need to do that in summer when the food is plenty. But you would in winter. After the winter solstice you’d know there will be two more cycles of the Moon and then spring would come. Here was their calendar!

640px-Sarmizegetusa_Regia_2011_-_Large_Circular_Sanctuary_and_Solar_Disc-1
An intricate Dacian Calendar at Sarmizegetusa Regia. Dacians were my ancestors so this photo is here because of my bias.

Food security or not (as not everyone had been subjected to very cold winters) the birth of Mithra, was observed after the 25th of December – a day which became Christmas, when the God of Light /Sun was re-born. So what is the story with that?

Former Carter Observatory educator Frank Andrews told me that the correct date of the “birth” was in fact observed a few days after the solstice.

A few days after…

As the Earth orbits the Sun, there is a subtle change in where the Sun rises and sets every day. This is in fact a cyclical change, a pattern that repeats every year: as seasons’ change, the Sun’s position at sunrise and sunset will be lurking sideways, little by little every day. It will do that until it will reach the northernmost point and then it will start going back, journeying towards the southernmost point – just like a pendulum. This is because Earth’s axis does not change as it revolves around the Sun. In summer, the one of the poles is leaning towards the Sun and the other pole away from the Sun, which is why the seasons are reversed in the two hemispheres. But we can’t see that from Earth, we had to imagine it by looking on the horizon and noting how the Sun changes its setting and rising azimuth throughout the year.

equinox
This is a great collage taken by Anthony Ayiomamitis in Greece. He took pictures of sunrise at the Winter Solstice, at the Equinox and at the Summer Solstice. You can see how the position of the rising point of the Sun is changing with the season

So if you were the Chief Astrologer/ Druid / Grand Priest and your job / head depended on knowing exactly when the days are getting longer again, you would keep a close eye on the rising /setting Sun. When the the seasonal movement of the Sun’s daily path (as seen from Earth) paused at the northern limit before reversing direction, from Earth, you would see that as if the Sun rose two days on a row from the same spot: on the solstice day and next day after the solstice, say 21 and 22 of December. By the 23rd, you would note the Sun starting to sneak in the opposite direction as it changed its rising and setting place by a tiny observable bit. If you were not sure, you would come back for one more day to see if it changed its rising azimuth again. So on the 24th of December, looking again, now you could be absolutely sure that the Sun definitely started it’s journey back, the shortest day of the year had gone, which is why this date could have been so important, people would be happy that the worst had passed. 

The shortest day of the year also known as the Winter Solstice means in Latin “sol” – “Sun” and “sistere” – “when the Sun stands still”.

The Sun has been doing this for about 4.5 billion years but of course we only started to notice it only about 20 t0 10,000 years ago. We don’t really understand our past a lot of times, hence all these explanations that people try to come up with,  the festive season and the shopping spree, could have originated from a time when people had little resources. We sometimes forget why we do things but we can look at them with a critical eye. Most of important festivals in the ancient central European world were celebrated just around and after the solstice. The days were very short, the nights were long, temperatures low and work in the field was done for the year, TV was not invented yet. What else was there to do?

Into the future

This picture of the Cathedral of Salamanca astronaut, grabbed my attentions for two reasons: 1. Salamanca is at the antipodes of Wellington, NZ, where we live, and 2. this was an approved modern addition to the Cathedral. Hopefully our offsprings will have an easier time deciphering this than we do when we are thinking about Christmas and winter solstices celebrations.

e93dd90dd4d611459c5b655b38999af5
Jeronimo Garcia was given the go-ahead to add some more modern images to the facade including an astronaut floating among some vines. Among the other recently added images are a dragon eating ice cream, a lynx, a bull, and a crayfish.

Clear Skies and Happy Winter Solstice!

P.S. – the Solstice on Mars

Since I also believe that in the future we will go to Mars, for the record, here is a picture of the solstice on Mars:

The rover Spirit  the Martian sunset from Gusev Crater on April 23, 2005 (note that a Martian year is twice as long as a year on Earth so the dates are Earth dates). Using data from images such as this, scientists have learned that twilight on Mars is longer than on Earth, lasting for up to two hours before sunrise or after sunset.

Scroll to Top
%d bloggers like this: