Tag: Equinox

The day after the Equinox we look at the cardinal points of the compass:

“chief, pivotal,” early 14c., from Latin cardinalis “principal, chief, essential,” (online etymological dictionary).

The Importance of South

On its annual cycle, the Sun is always on the move. At the Equinox the Sun now rises due East, and sets due West. It then rises every day further towards the north and sets further to the South until the Solstice. The Solstices mark the extreme Northerly and Southerly rising and settings. Dawn and Dusk vary accordingly.

So, the only real fixed point in the Sun’s entire journey (as seen from Earth) is Noon. Every day of the year, every day of our lives, the Sun is at the highest point at Noon. And this is the definition of South. But the Sun never strays into the North. So the North is the polar opposite of the South- cold, remote, more mysterious, unknowable almost.

To my mind, it makes, of the Cardinal Points, the South very special. At Stonehenge, there are two exits. The biggest is aligned to the Midsummer Sunrise and Midwinter Sunset axis. But there is a smaller second entrance and this aligned due South. There is also a uniquely small standing stone in the main circle of Sarsens, which is aligned to the South. (Although we don’t know if this stone is original). However, there was some sort of corridor heading South through the mysterious wooden phase which precedent the stone Stonehenge. So, we can be fairly sure South was important at Stonehenge.

Noon, derives from ‘nona hora’ in Latin and is ‘one of the seven fixed prayer times in traditional Christian denominations.’ (Wikipedia)

The Predominance of the North?

And yet, North, has come to be the principal of the cardinal points. It is shown on virtually all modern maps. It is the direction that people of my generation and hemisphere think of as being ‘up’.

The Google generation sees things differently. There are countless tourist maps on walls or plinths where North is no longer at the top. Up is shown as being the way you are facing. Users have to fight with Google Maps to put North at the top of the map. My children mock me when I say ‘Out of the Tube station, turn up the High street northwards.’ Their view of maps is completely contextual. They do not see any reason to know where the cardinal points are. I point out that the Tube probably has two exits on either side of the road. So, it doesn’t work to say ‘turn left out of the tube’.

There may also be an element of sexual difference, with men more likely to have a cardinal point view while women navigate more by landmarks. ‘Walk past the M&S, turn left to the Park and straight on’. One paper says: ‘during spatial navigation, women typically navigate an environment using a landmark strategy, whereas men typically use an orientation strategy.’

Although I see this decline of the north as being part of the Decline of the West. I also ‘things were better in my day’. But in fact it is simply returning to the way maps were produced in the past. Here is an example below.

The Magnetic Poles

Of course, there is another version of the cardinal points: the magnetic cardinal points. The magnetic North wanders over time. It does not necessarily coincide with geographic north. In recent times they are close enough. But in the past there have been huge variations. Occasionally, the earth has had geomagnetic reversals when the North Pole has pointed in different directions, including south. The last one was 780,000 years ago. On average, they take place very roughly every 500,000 years.

The magnetic pole is caused by the molten iron in the earth’s core and mantle, which creates a dipole. Fluctuations in the dynamo flow of the molten iron cause occasional reverses. The science is very complicated and, even now, not entirely understood. Is it a random consequence of flow dynamics? Or do external events, like sinking continents, or meteor strikes cause the reversal?

Since the first use of compasses for navigation in the 11th/12th Centuries, the magnetic pole hasn’t wandered enough to be of concern to navigation. It has wondered a few hundred miles over the last 500 years. Now, it is speeding up, from 9km a year to 52km (since 1970). This Wikipedia page is pretty good at an explanation.

My Job Tracking the Cardinal Points

My first proper job after university was as a technician then research assistant at Oxford University studying these phenomena. I say ‘proper’ because when I left University, I became an itinerant archaeologist. This led me to digs in Switzerland, Northampton, East Anglia and Nottingham. Then, I got the job at the Research Laboratory for Archaeology and the History of Art, at Keble College, Oxford.

I worked for Dr. Mike Barbetti who was an expert on the wanderings of the Magnetic Pole. His interest was firstly in the pure science of the subject. But he was keen to explore the applied uses in Archaeology as well. So, after being appointed as a Research Fellow at Oxford, he set up an epic journey from his native Australia to Oxford. It went via some of the iconic sites of Palaeolithic Archaeology, including Olduvai Gorge, Tanzania. The site of excavations by Mary and Louis Leakey.

To plot the movements of the magnetic north, scientists needed dated samples. Early human sites provided dated sites over a long time span. Also, archaeomagnetism, as the discipline became known, offered the possibility of dating sites. Another application was to determine whether deposits were fired or not. One of the sites Mike sampled was a candidate for the first evidence of fire in human existence.

Cutting up Samples

As I said, Mike’s interest was discovering how the magnetic field of the earth changed over time. And, more importantly, what was the mechanism. He shipped back to Oxford samples of soil cast in Plaster of Paris. My job was to cut the samples up. I cut them up with an electric saw in a shed in the backyard of the Laboratory. Then we measured the direction and intensity of the magnetic field in the samples.

Soil contains particles of iron, and they align randomly. So a sample of soil has a low magnetic intensity and a random direction of magnetic field. But once heated up, the iron particles align to the current direction of the magnetic pole. Its intensity is proportional to the intensity of the Earth’s magnetic field. These measurements provide a method of plotting the changes of the magnetic field over time. And from these data, models can be constructed explaining how the iron in the earth’s core worked as a giant magnet.

Once we had built a reference curve for the movements and intensity of the magnetic pole over time, we hoped to develop another dating method. Other methods such as radio carbon, thermoluminescence, and tree ring dating, were being developed at the Research Laboratory in Oxford.

My part in Digital Heritage Part 1

Having got the results, I took them to the Oxford University Computer Centre. There, I typed them up onto machine-readable cards. Added a copy on cards of our computer programme written in Fortran, and gave them to the Computing Staff. The program and data were run through the Centre’s mainframe computer. (probably an IBM or ICL computer, the size of a house!). 24 hours later, I received a print-out to proofread.

I located mistakes, ran an editing run of punched cards, essentially instructing the computer: ‘on card two replace 2.5 with 2.6, and run the programme again’. I would pick up the results 24 hours later. It seems extraordinarily primitive now, but then it was an enormous saving of time.

And that, patient reader, was my early contribution to Digital Heritage and pure science. Mike published many articles of which I was joint author of three articles, two in the prestigious Science Journal Nature. And it is annoying that my citations in the groves of academia are still dominated by articles I co-wrote in the late 1970s/80s!

Mike’s work was important in the development of the study of the earth’s magnetic field. However, the use of archaeomagnetism has never risen above strictly limited. Occasionally, in specific circumstances, it can be useful. But those circumstances tend to be times when no other methods have worked. Most often, it is used in attempting to date kilns.

These are the papers:

Barbetti. M and K. Flude, ‘Palaeomagnetic Field Strengths from Sediments baked by Lava flows of the Chaine des Puys, France.’ Nature, Vol. 278 No 5700. 1979

Barbetti. M and K. Flude, ‘Geomagnetic Variation during the Late Pleistocene Period and changes in the radiocarbon time scale.’ Nature, Vol. 279 No 5710. 1979

Barbetti M., Y. Taborin, B. Schmider and K. Flude ‘Archaeomagnetic Results from Late Pleistocene Hearths at Etoilles and Marsangy, France’. Archaeometry 22. 1980

More on my contribution to Digital Heritage in posts to come.

OnThis Day

Duel Day is celebrated when the Duke of Wellington fought a duel against George Finch-Hatton, 10th Earl of Winchilsea, because of disagreement about Roman Catholic Emancipation. The duel was in Battersea Fields on 21 March 1829

First written March 2023, revised 21st March 2024

So, Spring has sprung, not only meteorologically speaking but also astronomically. We are 20 days into the meteorological Spring which started on 1 March (see my post here.) Today, we are starting the astronomical or solar Spring.

The 20th of March is the Spring Equinox, or Vernal Equinox, midway between the Winter Solstice and the Summer Solstice. The sun has been rising further north each day since December 21^st. Today it rises due East, and sets due West. The day and night are roughly equal in length (although by no means exactly). At 9.00am today, the Sun was directly overhead at the Equator.

The term vernal comes from the Latin for Spring, and today is the primavera, the first day of Spring. The Anglo-Saxons originally used the word lencthen (Lent) for Spring. But later adopted the idea of the ‘springing’ of the year when the plants bud. In Middle English, the word Spring is also used for sunrise, the waxing of the moon and the rising tides. These are called spring tides. But also for the sprouting of the beard and the first appearance of pubic hair! Happy Spring Time!

Up to the 15^th Century, the English also used the French term ‘prime-temps’ in the sense of ‘first times’. This follows the idea that the year is young, while Winter represents old age. As we shall see, on March 25^th, there was also a belief that the world was created in Spring at the Equinox. Jesus was also conceived at this point of the annual cycle. (see my post /march-25th-the-beginning-of-the-universe-as-we-know-it-birthday-of-adam-lilith-eve-conception-of-jesus-start-of-the-year)

Zodiacally, if that is a word, Spring is Aries (brave and impulsive); Taurus (sensual and stubborn), and Gemini (dynamic and talented).

Druids at Tower Hill

The Druids have a ceremony at Tower Hill every year on the Spring Equinox. When I last attended I remember the druid costumes were often made with nylon sheets, and their footware was mostly tennis shoes. I see from the photos the nylon has at least been replaced with cotton, and the plimsolls with trainers. Not quite sure what that pair of black trainers are doing in the picture!

As my photos are getting long in the teeth, I have used photos by Heike Herbert. She attends most years. The ones above from 2 years ago. She has also been there today. However, she reports that the atmosphere has been affected by a street food market,. This restricted the space for the Druid Circle. The food stalls are there every Thursday, so it only impacts the Druid assembly once every 7 years! I wonder if anything similar happened at Stonehenge?

Modern Druids

I say modern druids because there is no convincing evidence that the modern fellowships of Druids can trace their origins back to prehistory. Druidry was reinvented in the 18^th Century — for example, the Ancient Order of Druids was formed in 1781. They were set up as societies in the tradition of the Freemasons. They held to belief in the fundamental importance of nature. However, one group, the British Circle of the Universal Bond, claim descent from a group persecuted by the Bishop of Oxford in 1166. Look at their website for more details and for an idea of their beliefs.

Prehistoric Spring Equinox

When did the Equinox first had importance for human society? The answer is, probably, at least as long as we have been reasoning creatures. On January 14th, I draw attention to a recent discovery by an amateur ‘citizen scientist’. He suggested there was evidence in Cave Painting for the use of a Palaeolithic Calendar. Follow this link to see the post.

Stonehenge and the Sun

At Stonehenge, in the old Car Park, they found three huge Pine post-holes in a line. Dating evidence shows they were erected in the Mesolithic period, thousand of years before Stonehenge. They align to the direction of the Mid-Summer Sunrise and Mid-Winter Sunset (NNE/SSW). If, and it’s a big if, you were sighting from Stonehenge itself, which was built some 5000 years in the future.

It is a bit of a stretch using two pieces of evidence so far apart in time. But recent excavations have revealed that there are natural periglacial striations in the soft chalk bedrock at Stonehenge. These lines point to the Solstices. They not only predate Stonehenge but also the three post holes. The striations may well have been visible from the time they were created when the glaciers melted.

Around 12,000 years ago (date from my memory so approximate), the climate changed and the glaciers melted. This left a lot of water rushing around the landscape. At Stonehenge, it gouged out striations in the chalk. By chance, or as ordered by the Gods/Goddesses/Divine Nature, the striations pointed to the Solstice Axis. Richard Jacques excavations in the Stonehenge area revealed that the aurochs came to the Stonehenge area for grazing and water. Aurochs are huge wild cows with enough meat on them to feed 200 people. So, the solar axis is near a place where the Gods/Goddesses/Divine Nature provided super-abundance in the guise of herds of Aurochs.

Burial Mounds aligned to the Equinox

This is confirmed by the alignment of many megalithic monuments dating from 3,600 BC onwards, including, of course, Stonehenge. Also, all around the UK are long barrows and other burial mounds, many of which are indeed sited/sited E-W to the Equinoxes. Many are fairly approximate. But at Loughcrew, County Meath in Ireland the Vernal Equinox shines right into the burial chamber. The sun’s light shines onto a stone marked by stone carvings. Similar alignments exist at Knowth and Dowth in the Boyne Valley. More about Loughcrew in my post here)

Harmony & the Spring Equinox.

The Equinox also has another role, which is to be the anchor of the cardinal points. The world is orientated to North, South, East, West. The Equinox is a time when there is a harmony, a balance in the universe. Therefore, it is a fortunate, a lucky time, a time to fall in love or undertake notable undertakings. But, in the Christian world marriage traditionally had to wait a little longer, until after the commemoration of the death of the Messiah,

First Written in March 2023, and revised in March 2024, 2025