h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Kepz
Hello! Thanks for your article, it's really interesting. But I don't understand what particular cases give birth to a single wave and ..why? Why not a classical wave?
tyPo

Solitons generally form due to a balance between something that makes the wave spread out, like dispersion, and a non-linearity which makes big waves bigger and narrower. Water has both - if you drop a pebble in a lake the ripples spread out, but get smaller and wider the further out from the centre they go, because of dispersion. But out at sea, big waves tend to get bigger and narrower until they fall over themselves. A soliton is where the two effects counter-balance each other.

'Classical' waves assume the stuff the wave is passing though is linear, ie it's response doesn't depend on the wave itself. As the article says, the maths behind these waves isn't easy, because of this non-linear stuff.

Chris.

Hmm, thanks.

Then, assuming some of the elementar particles are solitons in a way ( I suppose it would be those that are stable when left to themselves, the others being kind of thinning waves ), how is the "stuff they go through" non-linear, since it is vacuity?

If you imagine elementary particles as distortions of the space-time continuum it makes sense, because Einstein's equations are highly non-linear.

So, the carrying non-linear medium of these particles is space itself.

capito!