black hole physics/composition

A lot of people talk about black holes as 'singularities' which to me interprets to mean 'point'. Has anyone thought of black holes matter as having volume?. I guess I would think of it as a sphere, like a compressed sun, inside the event horizon, probably compacted to a fraction of the event horizon's diameter but with at least some volume. Has anyone thought about it like this?This message has been edited by AdminSylas, 05-20-2004 08:12 PM

Thread moved here from the Proposed New Topics forum.

For unknown reasons, this topic is not showing on the All-Topic list.We'll see if this bump does it.AM

I'll be interested to hear this one.

No, physicists don't think of it like this. In classical physics, there is no limit to how far the mass inside the event horizon will be compressed. Any finite volume is impossible, because the field is such that everything will continue to be drawn towards the middle, and cannot be stopped by any force.What this means, effectively, is that classical physics breaks down at this central point. That does not mean that there is a different theory which is able to sustain a very small sphere. It means that the descriptions of reality need to be something unlike anything in normal experience, even more strange than the weird ideas of a hole in space.The guts of the problem, as I understand it, is that we don't as yet have a well worked out theory of quantum gravity, which is what is required. The condition of mass and energy inside the event horizon will be something quite different from normal ideas of space and volume and mass and particle; but we don't really know what.Cheers -- Sylas

I was always under the assumpition the singularity could not shrink to a size below plancks length.

At this point we need a real physicist to comment; I've just hit the limits of my understanding.But my understanding is that it makes no sense to speak of sizes below Planck length; they are not really meaningful. That is, the Plenck length is not a limit on how far it shrinks, but a limit on how far the classical notions of space and shrinking even make sense.Here is an answer from a physics student, at physlink.com: A much more complicated discussion is available from John Baez at the Usenet physics FAQs. See The Planck Length.Cheers -- Sylas

And, as Sylas says, at this point* we need a theory of quantum gravity.*No pun intended.

This is where people have such a hard time with the concept of infinity. Theoretically, and mathematically, the singularity is infinitely small. Since it is infinitely small, it has no volume. Since it has no volume, some scientists think that it literally "falls" out of our universe.That was just an overly simplified explanation given by the discovery channel. As for the real explanation, I don't know the first thing about quantum mechanics.

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The Laminator

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A lot of people talk about black holes as 'singularities' which to me interprets to mean 'point'. Has anyone thought of black holes matter as having volume?. I guess I would think of it as a sphere, like a compressed sun, inside the event horizon, probably compacted to a fraction of the event horizon's diameter but with at least some volume. Has anyone thought about it like this?

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A few years ago, the idea of "gravastars" was presented. A gravastar was a proposed alternative to a black hole in that instead of a singularity there is a "shells of extremely dense matter with exotic space inside". I don't think the idea got too far. Black holes are still the leading explanation.

U235A singularity is a infintesimal point of zero size.The idea of a point of zero size is probably a source of confusion.That is why physicists describe it as ahving fallen out of the universe.Planck length,I learned from this website is "The length scale on which the quantized nature of gravity should first become evident"Planck Length -- from Eric Weisstein's World of Physics

I do not believe the singularity and the event horizon 'cloaking'it are contiguous. Going beyond the event horizon exposes you to the singularities 'zone of control' as it were. In this context, 'singularity' is a term which indicates 'the point at which all our physics break down'.

Once a star with a large enough mass exhausts it's H fuel it begins to cave in from gravity . The compressed star shrinks to a point called a singularity. It is infinitely microscopic and infinitely dense. This tears the very fabric of space/time. This phenomenon is now theorized to be responsible for the formation of galaxies. One expression of Volume is =m/d
Black holes have zero volume and infinite density in theory. Note the word 'theory" Physics experts feel free to correct my understanding of this.

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"One is punished most for ones virtues" Fredrick Neitzche