it's a rabbit -- no, it's a duck -- no, it's a rabbit...

I've been reading about phase transitions in one of the books I've got on the go. A phase transition, as I understand it so far, describes the behaviour of an entity that switches from one state to another, with no intermediate states. For example, H20 has three forms: solid (ice), liquid (water), and gas (steam). There are no intermediate forms -- as ice approaches the melting point, it doesn't get thick and sludgy: it goes straight from the solid to the liquid form. Similarly, when it boils, water turns into steam with no 'transitional' form.

Your brain does something analogous sometimes. For example, when you look at one of those visual illusions, like this famous one, and your brain flips from image to image, without them being able to coexist. There's also something similar going on (I think, perhaps naively), when what you've interpreted as one thing suddenly resolves itself into something else: like when you stare at a shape on the garden path, convinced that it's a bird sitting there; then the wind blows, and you realise that the 'bird' is a curled, dried leaf.

Cycling to work this morning, I emerged from thick mist into slightly clearer air (it made me think of the opening of the second episode of Band of Brothers, when the lone C-47 plane breaks out of the thick cloud and into the clearer night -- but I didn't do any of the sound effects, honest). I rounded the corner at the Wolvercote roundabout, and saw a shape on the cycle path ahead of me: it was a dark mass, with a rim of orangey red. It looked just like a hedgehog that's been badly crushed by a car -- the mass of dark body and prickles, and the brighter colour of the exposed viscera: I remember seeing one like that one morning when I was doing a milkround...driving along in the float on a beautiful summer morning, about six o'clock; the milkman stopped at the paper shop for his fags and porn magazine, and, as we drove back out onto the road, we passed a freshly-killed hedgehog, it's blood and flesh horribly bright, and glistening in the sunshine. I remember it made me feel a bit sick, to see that detail and colour so close.

Anyway, that's what I thought I was looking at this morning. As I got right up to it, though, veering aside a bit so that I wouldn't crush it any more, it resolved itself suddenly into the black and orange packaging of a Ginster's pasty thingy. I felt a proper nana, I can tell you (guv).

I never knew that they made them out of hedgehogs. Yuck.