Enough with the ash clouds already!

Kate and Anya were meant to be visiting relatives today in Wauchope, near the central NSW coast. But plate tectonics has put paid to that after a volcano blew its top in Chile, so they've switched to a flight early tomorrow.

This has got me thinking about pattern recognition and randomness. There certainly seem to have been a weirdly large number of scary ash clouds of late: I'd never heard of the things disrupting flights before Eyfynditturmouthful or whatever it's called went up a couple of years back. But when we were in the UK last month we missed the Grimsvotn disruption by about a week; and now this.

I'm pretty sure this is all random coincidence. Certainly there's more flights up there, meaning more chance of ash-related disruption; but on a quick Wikipedia check I can find only two incidents of planes actually running into ash clouds from 1982 and 1989 (scary!), and then a whole lot of nothing till this current cluster of cancellations. That feels so un-random that I can't help feeling there's some other factor at play.

I remember ages ago reading an article (now offline, but a summary is here) about how Apple had to re-engineer their iPod 'shuffle' function because people didn't believe it was truly random. They found their favourite tunes coming up again and again, and concluded that the iPod was secretly selecting tracks to please them, like an over-solicitous friend with a jukebox and a pocketful of change. Whereas in fact, it's entirely predictable that a device you have painstakingly loaded up with all your favourite tunes will frequently wind up randomly playing your favourite tunes.

I'm no expert on the mathematics of this, but it's an interesting reflection on the fact that our brains are hard-wired to see a smooth, even distribution of information as random--when in fact that sort of pattern is highly organised. The sort of random clumps that turn up all the time in nature--in the distribution of galaxies, or rock types, or coin flips or prime numbers or ash clouds--intuitively feel so structured that we find it incredibly difficult to recognise them as anything else.