I wanted to share some images with you that had me transfixed when I was a young boy (and still do to this day). I recall first seeing them in a hardback book of my father’s called Cosmos (which presumably accompanied the TV series that was being broadcast at the time).
The images depict the fate of our planet as the Sun transitions into a red giant star, at the very end of its life, some 4-5 billion years from now.
As the temperature of the Sun slowly increases, the oceans recede and our precious atmosphere is stripped away. Eventually the whole horizon is overwhelmed by the Sun in a bloated distended form, with the final image showing the Earth completely barren and parched.
I remember wondering at the time – where would all the people and animals be? Would we perish or find some new star to call our home? I think it was the first moment I glimpsed the immensity of stellar time scales and how tiny human lives and endeavours appeared to be next to these vast physical processes.
This is still what fascinates me most about astronomy and cosmology, and it’s amazing how something as natural and simple as looking up at the stars is a gateway into these incredible realms of the imagination.
Anyway here are the images, including their original captions. I was also pleased to find out that Adolf Shaller is still producing amazing art. Try an image search on Google with his name and enjoy.
Changing position of Sunrise from a fixed location over a year
The changing position of Sunrise throughout a year from a fixed location. The further north or south of the equator we live the more extreme our seasonal changes and the bigger shifts we perceive in the sunrise or sunset position during the year. In such harsh and changing seasons it would also have been the more important for ancient cultures to mark the seasons.
Using the landscape to mark the seasons like this is called a horizon calendar. But what if your horizons are flat and featureless, or you require more accuracy, or you’re a powerful priest and wish to theatricise important changes in time?
Then ‘perhaps’ you construct an artificial horizon by placing large stones to mark the progress of the Sun – a henge.
In view of recent developments my contribution to this years Inverness Science Festival will be a free live streamed talk. Please visit my Highland Astronomy facebook page for more details:
Astronomer Stephen Mackintosh will take you back in time to discover how our distant ancestors used the Sun, Moon and stars to track the progress of time and the seasons. Looking at ancient monuments connected to the night sky, we’ll go on a tour of Egypt, Central America, southern England and back home to Scotland where some of the finest concentrations of neolithic structures exist anywhere in Europe, not least the wonderful Clava Cairns. Plus advice on sky watching and naked eye observing you can put into practice yourself.
Note: this event is free and will be live streamed online as part of the Inverness Science Festival’s adjusted programme.
The main henge posts are now in place. Markers and smaller posts for the Celtic cross quarter days still to be added.
More progress on the wood henge and Celtic calendar up at Abriachan Forest, with the main posts for the meridian, equinoxes and solstice rise and set positions now in place.
Not quite finished yet. Abriachan plan to sow seeds for next few weeks and let the ground within the perimeter settle.
Descriptive marks for the main posts and small posts for the Celtic Cross Quarter days Imbolc, Lammas, Samhain and Beltane will be added later.
In addition to tracking the Sun and measuring the solar year, we can use the henge during the stargazing programme to record the rising of new seasonal constellations in the East and rough measurements of the transit altitudes (due south) and azimuth positions of the stars.
We also had a great kick off to the Star Stories program last night with ancient astronomy learning, storytelling and activities for the young ones.
The next event will be Nov 23rd with guest astronomer and author Steve Owens (aka Dark Sky Man). Booking links will go up shortly.
I had a fun afternoon surveying the markers in preparation for the final Wood Henge up at Abriachan Forest.
The final construction will mark the meridian from north to south, the equinoxes, mid summer and mid winter rising and setting positions of the Sun. Between the main solstice posts we’ll eventually place markers for the ancient cross quarter days, or Celtic Wheel of Time.
A simple henge like this can track the solar year, lunar rising positions and the changing constellations in the night sky.
Solstice celebrations up at Abriachan tonight. We had a nature walk and talk up to the Shieling above Loch Ness, with Suzann, Christine and Clelland imparting plant and flower lore at various points up the trail. From the top we learnt all about Shieling life, dairying and got to sample some simple crofting fare.
I then presented a short talk on the Solstice and its astronomical significance, culminating in a human henge to illustrate the changing seasons, rising and setting Sun points and how the ancient Celtic people marked off their Wheel of Time.
We just managed to catch a lovely sunset from the top of the hill before making the trek back down.
The Star Stories events will be resuming in October with another event in collaboration with the Highland Archaeology Festival. Look out for programme details as they emerge.