The discussion centers on the concept of neutron stars, specifically questioning whether they can have a minimum volume and exploring the implications of their density, mass, and properties such as angular momentum and magnetic fields. The scope includes theoretical considerations, speculative ideas about artificial neutron stars, and comparisons to other dense states of matter.
Participants do not reach a consensus on the possibility of neutron stars having a minimum volume or the feasibility of creating smaller neutron stars. Multiple competing views and uncertainties remain regarding the properties and implications of neutron stars.
Discussions include assumptions about mass, density, and the stability of neutron stars, as well as the limitations of current experimental capabilities to replicate such extreme conditions. There are unresolved questions about the relationship between neutron stars and other dense states of matter.
Not that much - smaller than the star that collapsed. Large v, but small r doesn't make a large product vr.nitsuj said:Angular momentum anyone?
nikkkom said:Fast rotation of NS does not strike me as particularly amazing, considering other properties on NS.
Such as magnetic fields with astounding energy density, more than energy density in a form of "usual matter" around us.
Just think about that. Antimatter is often thought of as "ultimate energy storage" in terms of density, ~1000 times denser than U235.
But here, we have just the "boring old" electromagnetic field, in vacuum, tangled up so tightly, it has much, much more energy per unit volume than antimatter (at STP) would!
Magnetic reconnections on the Sun cause solar flares. This is basically magnetic field jumping into a less energetic configuration.
Magnetic reconnections on a NS are far, far, *FAR* scarier. They happen in microseconds, they release energy equivalent to many tons of mass, and (since it's *EM* field) they easily convert this energy into EM waves, meaning gamma-rays. The "empty space" filled with magnetic field suddenly turns into a gamma-ray inferno.
Everyone knows about immense gravity on the surface, but just how immense it is, it's hard to visualize.
On the surface, a test object would fall one meter in about one millisecond - and attain velocity of several thousand km/s!
If a material baryonic object (a rock) would fall on NS from infinity, it would heat on impact to the temperature on the order of *trillion kelvins*!
mfb said:Well, compared to everyday objects or planets the angular momentum is huge, of course. Compared to other objects with a similar mass as the neutron star it is not.
Even if a smaller amount with that density would be stable, you couldn't play with it, [any]thing large enough to be visible would just crush the ground and fall towards the core of Earth.
The quark gluon plasma created at the LHC is hotter than the core of neutron stars. It should also have a higher density.nitsuj said:Apparently at the LHC they've found possible "(quark &) gluon plasma", to which inserted in the article was a comment from a scientist that said "Besides black holes, there's nothing denser that we're creating." I wonder if that is the same as him saying, quark-gluon plasma is the last step before a black hole.