Friday, December 29, 2006

Astronomical dreams

Some years ago I had a recurrent dream in which I would wake in the middle of the night, walk to my bedroom window, and gaze up at a night sky speckled and daubed with thousands of multi-coloured stars, galaxies and nebulae, all visible to the naked eye. Like celestial Christmas lights, vivid reds, greens, blues, oranges and golds were mixed with the cold silver of ordinary starlight, and I would stare in wonder at the delicate pinks and purples of the nebulae, and the opalescent spirals of the galaxies. No doubt my subconscious imagination had been fuelled by the colourful vistas of magnified, wide-field, long-exposure astrophotography, but by placing all these individual images together upon the sable inner surface of the celestial sphere, my subconscious generated perhaps the most spectacular sight I've ever seen. This photograph of an aurora over Lake Michigan, reminded me of this dream, but remains a pale imitation in comparison.

6 comments:

Susan Balée said...

What a beautiful description. It reads like verse -- the music of the spheres!

clare said...

Yes, I agree - a vivid piece - and that picture is awe-inspiring too. The sky is such a strange acid yellow-green. I have never seen a sky that colour. I woner what causes it.

Gordon McCabe said...

As ever, many thanks for the compliments!

Clare, the picture is looking North over Lake Michigan at an aurora (borealis); low-altitude aurorae tend to be dominated by green light from oxygen, while higher-altitude aurorae tend to display red hues. If you look closely, you can see a faint red shade above the clouds, and when red and green mix it produces yellow.

clare said...

I am embarrassed now - my hero Alfred Wegener had a theory for this colour... I have just remembered - I read about it once but didn't associate it with something like this - a wash of colour. I looked at pictures of aurorae and thought they were swirls of light. I had no idea they could be like this. Thank you, Gordon, I am much enlightened now. (Wegener thought he had discovered a new element but I read later it was due to forbidden electronic transitions in the oxygen, I think. One of the rare instances when the man was wrong...). Just going to have another look at that picture again, I love it.

Gordon McCabe said...

Indeed, I've set that picture as the background on my PC, Clare!

I read in New Scientist last week that someone called Paul Silver has proposed that plate tectonics ceased altogether for 100 million years when the supercontinent of Rodinia formed, and may do so again in 350 million years' time when the Pacific ocean 'slams shut'.

clare said...

Well how interesting - I'll go and take a look. I missed that. Thanks again, Gordon.