Chris Lintott’s Universe

I’ve been trying to use art in my lectures and talks for a while now; I’ve written here before about how Anthony Gormley’s sculpture Blind Light helps me to think about the cosmic microwave background, and Escher’s Cubic Space Division is still the best way I know of explaining why we conclude that space itself is expanding.

A conversation today added to my list. I read on the Guardian’s website this morning that Keith Tyson was producing what he calls History Paintings; these prints, of red, green and black stripes and made available over the net, are apparently generated by an algorithm based on a roulette wheel.

I’ve been a fan for a while – his work is often scientifically inspired for one thing (and I tried quite hard to have him adopted as the artist for Bang! of all things.) And so, although only 5000 are (were by now, I should think) available, I managed to get in quickly enough to grab one. Here’s the result – History Painting (December, Oxford) :

I was quite disappointed there wasn’t any green. I wonder what the odds of that happening are? The algorithm isn’t clear from the information given in the paper, but we might guess that the odds of getting a green stripe in a particular position are the same as the odds of landing on green on a British roulette wheel; 1 in 38. That means the chance of getting no green at all would be just over 1 in 3. So my print, while pleasing, is nothing particularly special.

As the article in the paper notes, though, it’s possible that someone got an all-green image. According to my guess as to how likely green is, this would happen 1 time in 10^61 – that’s one in ten million billion billion billion billion billion billion. If I’d got an all green image, would I have celebrated my amazing luck?

I’m not sure. For starters, this run of roulette spins is exactly as likely as any other – it just looks special because it’s all green. I’d have to be thinking particularly mathematically to remember that, though, and maybe instead I would have suspected that the algorithm was not working as advertised (perhaps everyone’s is green, or the odds of getting green are less than I estimated).

Talking about this today in the department, I realised it’s a good analogue for looking out at the Universe; if we see an unusual or unlikely feature on large scales we have two choices. Take, for example, the presence of a large cold spot in the data from WMAP, looking at the early Universe as revealed by the cosmic microwave background.

If our models are correct, such a feature is fantastically unlikely, like an all-green History Painting. But there it is, so what do we make of it? We can either celebrate our ‘luck’ – of all the ways the roulette wheel of the Universe could have spun, it just happened to produce this interesting feature for us to look at. Or we can conclude that our understanding of the rules that govern the Universe is wrong, just as I might have concluded that an all-green image was a sign that the art-algorithm was broken.

Knowing when to do which is almost impossible, and one of the joys and frustrations of modern cosmology. Unlike artists like Keith Tyson, who can continually reinvent and respin the wheel, we only have one Universe to look at and must make do with whatever it shows us.