On Mon, May 12, 2014 at 06:11:07PM +1000, Rob O'Connor wrote:
> OK. I thought there was some suggestion from astrophysics that
> nuclear matter could be converted in an intense gravitational field
> e.g. inside neutron stars.

Ah right, I get what you mean now.  Yes, one theory is that if strange
matter is stable, then all neutron stars should be composed of it.
The extra fermion type would allow denser packing under their intense
degeneracy pressure.

I note that a lot of material talking about strange matter includes
only two strengths of hypothesis: 1) that strange matter can exist,
but only at enormous pressure, or 2) that strange matter is more
stable (i.e. lower energy) than nuclear matter.

I think there's a lot of room for an option 3): that strange matter is
stable within some range of nucleon numbers, but not of lower energy
than ordinary nuclear matter.  This seems the most likely to me.
Strangelets should still be positively charged and bound primarily by
the strong force, and should have both lower and upper bounds to the
size of nuclei in which they could be stable.

In this third case, neutron stars would have a crust of atom matter, a
mantle of some thickness of neutronium, perhaps an outer core of
strange matter, and maybe a quark-gluon plasma inner core.

- Tim