Re:Physicist steps in... (Score 2)

Hi, Bob!

The concern isn't about strange quarks; it's about a proposed state of matter called strange matter. Now I should disclaim here that, though I'm a physics grad student too, I don't know what I'm talking about, at least not firsthand... but I've heard people discuss it in seminars, so this is intended to distill those vain assertions, half-truths, and self-important obfuscations.

The basic idea is that nuclear matter as we know it--that is, stuff made of up and down quarks--is not the true ground state of QCD (the theory which models the interactions of quarks and such). It's possible that there is a stable state of matter which includes up, down, and strange quarks, all bound together; in fact, it's possible that that state is more stable than one which involves just up and down. Now normally we don't see this stuff, because there's a high energy barrier between our Plain Old Everyday matter and this strange matter. But if you get a high enough collision energy, you can tunnel through or just slop over the barrier; and then whammo! the strange matter overtakes the POE matter, like ice nine dropped into water. (Someone call Dr. Strangelove--we've got to guard our POE!)

For background, see this page and its links. If you want to wade through the hard stuff, try R. J. Holt et al., Physical Review Letters vol 36 page 183 (1976), and E. Witten, Physical Review D vol 30 page 272 (1984).

Elsewhere, coyote-san asks, "where are the strange stars from the same effect?" Strange stars are entire stars made of strange matter. People are looking for them, but so far there's no positive evidence. One of the problems, as I understand it, is that nobody really knows how they'd look different from plain old garden variety neutron stars.

The black hole possiblity sounds sexier, but I think strangelets are cooler. :)

jon