by Qev » Sun May 21, 2006 3:06 am
harry wrote:Hello All
qev said
I'm afraid it's not possible to have the mass of the sun compressed into an object 300mm in diameter and have it remain stable. Once the total mass of the Sun gets compacted within it's own Schwartzchild radius (which is 3km), you have a black hole; nothing can prevent its further collapse.
In this day an age i would not limit my thinking.
Well... that outcome is predicted by General Relativity, and I haven't seen anyone be able to poke holes in its predictions yet, not at the macroscopic scale. The problem is, once an object's mass falls within its own Schwartzchild radius, the escape velocity exceeds the speed of light. No force can hold up under that kind of gravitational field, as everything in the universe is governed by the light-speed limit (that we know of)... including all of the fundamental forces, which are what give structure and stability to matter.
Let us think outside the circle and look for the answer. I need someone to look at the possiblities. This 300 mm ball is theoretical and would probably require a density of about 10^18 to 10^30
compared to a neutron star density of about 10^18 or there abouts.
So if we multiply 10^30 by 300mm we get some mad number which is greter than the width of our sun.
Well, if you're looking for density, it's total mass divided by volume. For the object you're proposing, it would be on the order of 1.4x10^32 kg/m^3, which is an utterly insanely high density, far beyond anything that could be stable under its own self-gravity. Remember that a neutron star of much lower density than this will collapse into a black hole.
Even if it were somehow stable, it would still be inside an event horizon, and would technically be a black hole; it would behave exactly the same.
Maybe be so, but! what is the steps from a neutron core to a blackhole.
Well, there may be the 'quark star' stage, which has an estimated core density around 3x10^18 kg/m^3, which is roughly ten times more dense than the average neutron star's core density. But this is nowhere near the sorts of densities you're proposing.
A black hole is a state of matter that has the basic degenerated particals that make up all matter.
Its not a hole as so to speak of. But! just a massive compacted degereated particals.
I would not classify it as a singularity where all particals take up one point in space and time. I would assume that no two particals can ocupy the same space at the same time.
Actually, that's the problem: we just don't
know what the inside of a black hole looks like, or what happens to the matter that falls into it. Under General Relativity one gets a singularity, a point of infinite density and gravity, which physicists would like to avoid somehow, if they could. Until we have a decent working theory of quantum gravity, we'll never really be able to answer that question. It could very well be that all of the mass gets compressed down into a single 'super particle' or something equally bizarre. Who knows?
Also, some types of particles are quite happy to share the same place at the same time, and are called bosons. These particles have whole integer units of quantum spin. The other group, the fermions, have half-integer quantum spins, and must obey the Pauli Exclusion Principle, forbidding any two of them from sharing the exact same quantum state.
Sorry my computer has not been fixed yet, and cannot search for preon stars and so on. Can someone do that and look at the possible size of a preon star in theory.
Preon stars are estimated to have densities exceeding 10^23kg/m^3. They're also much lighter than neutron stars, being generally thought to mass up to 100 times the mass of the Earth. From what I've read, if these things can exist, they would do so at the very edge of collapsing into a black hole, since at those densities the radius of the object is almost equal to its own Schwartzchild radius. I imagine these things don't hang around very long, if they even exist at all. Preons, as a theory, aren't terribly widely supported.
[quote="harry"]Hello All
qev said
[quote]I'm afraid it's not possible to have the mass of the sun compressed into an object 300mm in diameter and have it remain stable. Once the total mass of the Sun gets compacted within it's own Schwartzchild radius (which is 3km), you have a black hole; nothing can prevent its further collapse.[/quote]
In this day an age i would not limit my thinking.[/quote]
Well... that outcome is predicted by General Relativity, and I haven't seen anyone be able to poke holes in its predictions yet, not at the macroscopic scale. The problem is, once an object's mass falls within its own Schwartzchild radius, the escape velocity exceeds the speed of light. No force can hold up under that kind of gravitational field, as everything in the universe is governed by the light-speed limit (that we know of)... including all of the fundamental forces, which are what give structure and stability to matter.
[quote]Let us think outside the circle and look for the answer. I need someone to look at the possiblities. This 300 mm ball is theoretical and would probably require a density of about 10^18 to 10^30
compared to a neutron star density of about 10^18 or there abouts.
So if we multiply 10^30 by 300mm we get some mad number which is greter than the width of our sun.[/quote]
Well, if you're looking for density, it's total mass divided by volume. For the object you're proposing, it would be on the order of 1.4x10^32 kg/m^3, which is an utterly insanely high density, far beyond anything that could be stable under its own self-gravity. Remember that a neutron star of much lower density than this will collapse into a black hole.
[quote][quote]Even if it were somehow stable, it would still be inside an event horizon, and would technically be a black hole; it would behave exactly the same.[/quote]
Maybe be so, but! what is the steps from a neutron core to a blackhole.[/quote]
Well, there may be the 'quark star' stage, which has an estimated core density around 3x10^18 kg/m^3, which is roughly ten times more dense than the average neutron star's core density. But this is nowhere near the sorts of densities you're proposing. :)
[quote]A black hole is a state of matter that has the basic degenerated particals that make up all matter.
Its not a hole as so to speak of. But! just a massive compacted degereated particals.
I would not classify it as a singularity where all particals take up one point in space and time. I would assume that no two particals can ocupy the same space at the same time.[/quote]
Actually, that's the problem: we just don't [b]know[/b] what the inside of a black hole looks like, or what happens to the matter that falls into it. Under General Relativity one gets a singularity, a point of infinite density and gravity, which physicists would like to avoid somehow, if they could. Until we have a decent working theory of quantum gravity, we'll never really be able to answer that question. It could very well be that all of the mass gets compressed down into a single 'super particle' or something equally bizarre. Who knows?
Also, some types of particles are quite happy to share the same place at the same time, and are called bosons. These particles have whole integer units of quantum spin. The other group, the fermions, have half-integer quantum spins, and must obey the Pauli Exclusion Principle, forbidding any two of them from sharing the exact same quantum state.
[quote]Sorry my computer has not been fixed yet, and cannot search for preon stars and so on. Can someone do that and look at the possible size of a preon star in theory.[/quote]
Preon stars are estimated to have densities exceeding 10^23kg/m^3. They're also much lighter than neutron stars, being generally thought to mass up to 100 times the mass of the Earth. From what I've read, if these things can exist, they would do so at the very edge of collapsing into a black hole, since at those densities the radius of the object is almost equal to its own Schwartzchild radius. I imagine these things don't hang around very long, if they even exist at all. Preons, as a theory, aren't terribly widely supported.