Transcript

Chaos Control is not easy, as our parents know. Indeed, it's so difficult you might think it's just impossible. After all, true chaos means that even the tiniest changes can have large and in practice, unpredictable consequences, like the butterfly in China that causes a tornado in Texas. If chaotic systems are so sensitive to small perturbations, trying to correct them could just make things worse. Maybe it's easier to let little Paul throw the spaghetti at the wall and clean up later. But surprisingly, it's indeed possible to control chaos. Just exactly. What is Chaos Control? How does it work? And what can we do with it? That's what we'll talk about today.

Chaos sounds mysterious, like something anomalous, a disruption of the normal order of things. But in fact, chaos is everywhere. The solar system, for example, is chaotic. In illustrations, the solar system looks like the most orderly thing ever, but we only know it to be stable for the next few million years after that, it's possible that one or the other planet gets spontaneously derailed from its orbit. The planet that's most likely to be affected by chaos is luckily not earth, but mercury. That's because its orbit gets close to the sun in almost the same time interval as Jupiter, if the two planets fall into resonance, that will probably destabilize the orbit of Mercury, because Jupiter is so much heavier according to computer simulations, what will happen then is that either mercury gets ejected from the solar system, or it falls into the sun or collides with Venus. Which way it pans out depends very sensitively on the exact orbits of the two planets. So we don't know whether it'll happen either way, though, it'll be quite a spectacle. So mark your calendar for the year 5 million more seriously, this is how chaos was discovered. By studying the solar system. In 1887 the King of Sweden offered a prize to whoever could show that solar systems in general, but ours in particular, are stable, and the planets will orbit patiently around the sun until the sun runs out of nuclear fuel.