# Chaos of Delight – Episode 20

*Charles Darwin wrote wonderful sentences, beautiful books and fabulous phrases and one of my favourite is when he describes his mind being a 'Chaos of Delight' after seeing many of the splendid lifeforms in a Brazilian forest. And we have asked everyone who's been involved in this App when they experience that 'Chaos of Delight.'* - Robin Ince

I have a concept

I have a concept, I have a way of speaking about this. It's my contribution to elementary particle physics, what is the elementary particle of sudden understanding? I call it the clariton, a...immediately everybody understands what I mean by that, you suddenly, ah, I understand something. The problem is when you're a theorist, there are also anti-claritons that the next day come and annihilate the one you had yesterday.

There are mini-claritons, mega-claritons, there's a whole set of concepts. Basically it's the clariton, and you can have them at different levels but they are moments of very very great delight when you really, really understand. I've had a few in my life and, of course, every day there are little ones, but I've had a few major ones in my life and these are great moments, claritons.

Well, yes, but they are technical things. You see, the thing that I'm best known for is something called the geometric phase, that's something in quantum mechanics, it's a technical thing. It's to do with how quantum systems somehow remember where they've been, it's to do with the fact that basically quantum physics is a wave of physics. And waves have phase, phase is a thing that goes up and down in a wave, and there are ways in which phase can measure which just hadn't been appreciated before.

That was a great moment, but the greatest moment is a purely technical thing. Much of the mathematics in physics involves what is called an infinite series, you can almost never calculate in science exactly what it is that you're wanting to understand. People think that physics is an exact science: it isn't. Mathematics is always just beyond what we can do exactly, and so we use approximations and then we improve them, we improve them, we improve them. And sometimes these improvements take the form of an infinite series of numbers, one plus a half plus a…OK, now there are deep mathematical questions about these infinite series and I won't describe them because it's too technical. But I had an insight, understanding an aspect of divergent series that was nearly 200 years old, and that was a great moment to understand that. And it's the thing I’m, in a way, most proud of. I'm known among mathematicians for this but it's nothing that the general public would ever be interested in. It pleased me.