Milky Way and winter

On December 12, 2025 By cornishstargazerIn cornwall, History of astronomy, Winter Solstice2 Comments

As the darkest of nights draws ever closer and the hours of darkness deepen. We can take comfort that the night is no empty space, the heavens open up for us and at this time of year our ancestors in the Bronze Age would have seen a great river of stars, now known as the Milky Way, arching across the sky above them. The Milky Way has long been both a boundary and a bridge. Across cultures its silvery light holds a shadow of darkness, imagined as a pathway for the dead or a dividing line between lovers. In prehistory it was likely seen as a place of wonder and story, perhaps a path trodden by gods and giants.
Perhaps those who carefully set stones as a link between the circles at the Hurlers in Cornwall, or on the ground next to the towering monoliths of Dartmoor’s Piles Hill, sought to mirror the heavens upon the earth. In doing so, they brought the stories of the stars within human grasp, creating an opportunity for transcendence by reaching out to touch the world beyond.
In Wales, the children of Dôn knew the Milky Way as Caer Gwydion, the castle of the trickster who strides across the firmament in pursuit of his elusive wife. And in that lost sky we may find the shadow of his companion, Bran the Blessed, raven-king of night. His presence remains in the Cornish hills at Mȇn Scryfa, a solitary menhir inscribed with memory of a royal raven, and at Caer Bran, the hillfort that bears his name. I like to think these are more than places of earth and stone, but gateways, places we may stand and look upward and perhaps trace the crow’s path along the starry river.
The dark skies, once alive with ancestral stories, are no longer what they were; they have been dimmed by our lights. Where once every soul knew the sweep of stars, now only a few of us get to glimpse the Milky Way. True darkness has grown rare. Yet we are fortunate in Cornwall, where it can still be found arching across the sky. To stand at Caer Bran or Mȇn Scryfa on a clear, moonless night and watch the Milky Way blaze forth is to walk another time perhaps beside the raven.

Happy winter holidays all

Megalithamania 2023

On November 11, 2023November 11, 2023 By cornishstargazerIn Bodmin moor, cornwall, History of astronomy, watchingthesun, Winter SolsticeLeave a comment

Back in May I was kindly invited to speak about the wonderful Cornish ancient sites on Bodmin Moor and the research I have been doing into the relationship they have with the sky. Here’s a link to the talk,

The Cornish mine experiment to Weigh the World part 1

On March 7, 2022March 7, 2022 By cornishstargazerIn cornwall, History of astronomy, UncategorizedLeave a comment

*Descending ladders into the mine to seek a suitable sub-surface location to run the experiment to measure the density of the Earth. Photograph credit: © Carolyn Kennett, 2021*

How did we weigh the Earth (and why did this go beyond simple curiosity)? This may be a question people asked themselves during childhood, and have not considered since. Yet it is a question a small group of scientists, including myself, have returned to as we research experiments conducted in the 1820s in a Cornish mine to measure the acceleration due to gravity of the Earth.

In 2022 our intention to re-create the mine experiments by building a replica Kater invariable pendulum and taking it down a Victorian mine in west Cornwall to make measurements of gravity. We will set the pendulum in two locations, one overground and one underground, and time the swing of the pendulum in both locations. The difference in the rate allows us to calculate the amount of gravitational pull on the pendulum, as the underground pendulum will swing at a slower rate. The original experiment was conducted by George Biddell Airy and William Whewell in the deepest mine in England, Dolcoath. This has unfortunately closed and the lower recesses are flooded, so we are using a mine named Rosevale, which gives us a difference of 250 metres between the overground and underground stations. Although Rosevale is not as deep as Dolcoath (700 metres at the time of the original experiment), it gives the opportunity to explore how the experiment was conducted in what can only be described as less than ideal conditions. Mines are dirty places which can be excessively damp and hot. During the original experiment the scientists would have had to contend with vibrations and noise from the working environment, making their achievements all the more significant.

Why is this all important now you may ask? Yes, simple curiosity does play into this but we find ourselves in a time when the power of gravity is something we have learnt to manipulate and overcome. There are frequent launches into space and discussions of journeys to far-flung destinations such as Mars. Without the arduous and at times dangerous early experimentations into measuring the gravity of the Earth untaken by Airy, Whewell and others we could still be stuck without the knowledge to reach beyond our own planet. Therefore we think it is the perfect time to highlight the work they undertook and their achievements in what was an important building block for us to travel into space.

Blog post first appeared here –

http://www.scientificinstrumentsociety.org/blog