Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Ultima on 28/12/2004 18:47:23

Title: States of Matter and Neutron Stars/Black Holes
Post by: Ultima on 28/12/2004 18:47:23
Hi all, I just got to thinking what state of matter are super dense stars in, is it still considered a solid I know that for the most part stars are plasma, but brown dwarfs or neutron stars? Or is it a Bose-Einstein Condensate, but this applies to anything at low temperatures not high density??? I've been reading around and some peeps give dense stars their own state, and at higher energy you get Quark-Gluon Plasma. But 7 states of matter seem a bit much??? Can any one help me out with what they know or think about this? Plus what about the singularity within a black hole, obviously its all theoretical, but would that be another state of its own?

wOw the world spins?
Title: Re: States of Matter and Neutron Stars/Black Holes
Post by: Titanscape on 30/12/2004 15:47:45
There are no dimensions in black holes, right?

Titanscape
Title: Re: States of Matter and Neutron Stars/Black Holes
Post by: Sandwalker on 01/01/2005 15:29:49
quote:
There are no dimensions in black holes, right?

Who knows. There could be a whole universe![:o)]
Title: Re: States of Matter and Neutron Stars/Black Holes
Post by: pink_person on 01/01/2005 17:23:29
quote:
Who knows. There could be a whole universe!


I thought that was with wormholes?  As far as I know, I thought that black holes were just big balls of collapsed gravity(stars).  Of course I'm not to knowledgable about these things.[:D]

Pink
Title: Re: States of Matter and Neutron Stars/Black Holes
Post by: qpan on 03/01/2005 11:10:47
Well, neutron stars are stars which contain matter so tightly compacted by gravity that they are the same density as the nucelei of atoms, which is quite impressive when you consider how dense the nucleus of an atom is, and how much space there is in an atom on earth. The nucelus makes up approximately 100% of an atom's mass, while only taking 0.000000000001% of the volume (on earth).
I'd still assume that it would be classified as a solid though (or maybe 1 giant atom? - only kidding, we've had this discussion before).

A singularity is a point, which i'd imagine is dimensionless. The laws of physics breaks down when reaching the event horizon of a black hole, so i doubt its classified as any kind of matter!

"I have great faith in fools; self-confidence my friends call it."
-Edgar Allan Poe
Title: Re: States of Matter and Neutron Stars/Black Holes
Post by: gsmollin on 05/01/2005 16:38:03
quote:
Originally posted by Ultima

Hi all, I just got to thinking what state of matter are super dense stars in, is it still considered a solid I know that for the most part stars are plasma, but brown dwarfs or neutron stars? Or is it a Bose-Einstein Condensate, but this applies to anything at low temperatures not high density??? I've been reading around and some peeps give dense stars their own state, and at higher energy you get Quark-Gluon Plasma. But 7 states of matter seem a bit much??? Can any one help me out with what they know or think about this? Plus what about the singularity within a black hole, obviously its all theoretical, but would that be another state of its own?

wOw the world spins?



The states of matter within the neutron star are manifold. There is a crust with solid neutrons, a mantle with liquid neutrons, a superfluid state and even the possibility of quark matter at the core. Nature seems to enjoy diversity.

The singularity in a black hole defies theoreticians at this time, although there must be something interesting happening in there.
Title: Re: States of Matter and Neutron Stars/Black Holes
Post by: neilep on 05/01/2005 18:00:56
This has always facinated me...Black Holes eh ?....when one says that the laws of physics break down, I always think (in my ultra limited way) that even the breaking down of laws must be governed by some rules. It's just that we don't understand them right now.  When we do understand, it'll seem perfectly sound won't it ?

'Men are the same as women...just inside out !'
Title: Re: States of Matter and Neutron Stars/Black Holes
Post by: Ultima on 05/01/2005 19:55:05
I thought that black holes are an inevitable result of our understanding of physics as they were hypothesised before any were "possibly found". So surely all physics doesnt break down if they were assumed to exist?

wOw the world spins?
Title: Re: States of Matter and Neutron Stars/Black Holes
Post by: gsmollin on 06/01/2005 01:59:18
Black holes is a difficult subject, maybe the worst. It combines GR and QM, which has not been unified. The singularity is hidden behind an event horizon so we can't see it. Roger Penrose postulated that all singularities had to be hidden behind event horizons, so that the universe was not exposed to a "naked singularity".

This gives rise to all kinds of difficulties, with thermodynamics, GR, QM.
Title: Re: States of Matter and Neutron Stars/Black Holes
Post by: OldMan on 06/01/2005 02:08:41
I read a little while ago an article from New Scientist titled Gravastars: The new Blackholes and could our universe exist inside one.

Anyone heard about these? Made for quite an interesting read and suggested that black aren't actually possible due to conflicting laws and such but Gravastars make up for the unexplained bits. I can't really remember much about it but maybe someone else knows a little something.

Tim
Title: Re: States of Matter and Neutron Stars/Black Holes
Post by: OldMan on 06/01/2005 02:10:58
http://www.newscientist.com/article.ns?id=mg17323264.700

ok there it is but looks like you have to subscribe to read the whole thing.

Tim

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