Exploring Black Hole Anatomy: The Singularity, Event Horizon, and Photon Sphere

[bill alsept]

I know there are several theories as to what may be inside black holes and that the standard model usually describes the geometry with a singularity surrounded by an event horizon and then a photon sphere.
Three questions:

Is there an easy way to calculate the distance and or ratios between the three?

Does the singularity have an actual size (diameter) like the other two?

Is the singularity always a point or are there any theories that model the singularity with an actual diameter that continues to grow as it accumulates matter?

 

[Vorde]

Singularities aren't well described by modern physics. General Relativity can describe the area around a singularity (a black hole), but the mathematics of GR give nonsensical answers at the singularity itself.

In terms of mathematics of the distance and ratios; yes, but I don't know them and 'an easy way to calculate' is probably not realistic: Einstein was a genius for a reason. The event horizon is simply the point around a mass where the escape velocity = c (the speed of light). While I know that some speculative physics models describe singularities differently (String Theory in particular), I believe the quasi-accepted current view on singularities is that they are points of no diameter and of infinite density.

 

[Chronos]

The Swarzschild radius gives you the basic relationship.

 

[bill alsept]

How does the swarzchild radius describe the relation of all three? Is there some proportionality between their radiuses?
This question becomes more interesting if we imagine a singularity with a finite density and therefore an actual diameter. How then would the three diameters compare?

 

[Chalnoth]

I don't think we can realistically trust General Relativity to give the correct answer to the behavior of a black hole inside the event horizon, unfortunately.

 

[bill alsept]

What if we just assume it is like any other mass? The fact that its g has an escape velocity of c doesn’t necessarily mean the body of the black hole has to be a point. If the singularity had a finite density and therefore a diameter would there be a way to calculate that diameter based on the mass?

 

[Chalnoth]

What if we just assume it is like any other mass? The fact that its g has an escape velocity of c doesn’t necessarily mean the body of the black hole has to be a point. If the singularity had a finite density and therefore a diameter would there be a way to calculate that diameter based on the mass?

Once you have enough mass in small enough an area to form a black hole, the pressure required to keep the matter collapsing actually increases the gravity, so that it becomes fundamentally impossible for any amount of pressure to prevent the collapse.

 

[bill alsept]

Why is pressure required to keep the matter collapsing? Did you mean keep the matter FROM collapsing? If something becomes 100% dense (as I believe the singularity to be) and cannot get any denser then how can it collapse any farther? And why would it need pressure to keep it from collapsing?

 

[zhermes]

The Swarzschild radius gives you the basic relationship.

To expand on this response (to make it even vaguely useful), the event horizon, photon sphere, and other interesting surfaces can all be easily calculated in GR for any type of black hole---with the different surfaces generally expressed in terms of the Schwarzschild radius (and other fundamental parameters, i.e. spin and charge).

I don't think we can realistically trust General Relativity to give the correct answer to the behavior of a black hole inside the event horizon, unfortunately.

Just to clarify, GR Is well behaved within the event horizon, its only near the singularity that it breaks down. In the case of a rotating or charged black hole, it can be a little worse.

The fact that its g has an escape velocity of c doesn’t necessarily mean the body of the black hole has to be a point.

According to GR, the central mass does need to be a point. Not only is the escape velocity equal to 'c'; but also, space-time is so distorted inside the event horizon that the only direction a particle can move is inward (i.e. its 'impossible' to even stay still--like on a hard surface).

Why is pressure required to keep the matter collapsing? Did you mean keep the matter FROM collapsing? If something becomes 100% dense (as I believe the singularity to be) and cannot get any denser then how can it collapse any farther? And why would it need pressure to keep it from collapsing?

He did mean "keep the matter 'from' collapsing". Pressure is always required to keep material from collapsing. The reason the Earth doesn't collapse, or the air in the room, or the table your typing on---are because of pressure. Once inside the event horizon there is no pressure strong enough to resist collapse (according to general relativity). There is no such thing as '100%' dense---something can become arbitrarily dense because it can become arbitrarily small.

People think that a new quantum theory of gravity might be able to explain what actually happens at the singularity. Most string theorists, for example, think that at some point the matter will reach a maximum density (and minimum size), at about the Planck scale---\sim 10^{-35} m; but no one really knows.

An additional thing to note is that charged and rotating black-holes have singularities that aren't points. A rotating black hole (called a "Kerr black hole") actually has a torus-shaped singularity (again, according to GR) with a finite, calculable size.

 

[bill alsept]

I realize pressure is required to keep stars and anything else that may have space inside from collapsing. My point is that a singularity MAY be as dense as anything can be. It can't collapse anymore and therefore would need no pressure to support it. If this were possible then the singularity would have an actual size and would be growing proportionately just like the event horizon and photon sphere. My original question was how could you calculate the diameter of the singularity? Hypothetically speaking.

 

[Vorde]

It can't collapse anymore and therefore would need no pressure to support it.

Incorrect. Not only can it collapse further, it has to. The whole weirdness of a singularity stems from the fact that its a point of infinite density.

 

[bill alsept]

How can it collapse further and why does it have to? Can't a black hole be so dense that there is no space left inside? An area filled 100% complete with the smallest partials the universe has to offer. There would be no more area to collapse to.

I realize my original question most likely cannot be answered because we don’t know how small those first particles are or how many have accumulated in the black hole. Could there be some indirect way to calculate backwards from the observed mass and event horizon and come up with either a diameter for the singularity or something.

We may need to think out of the box and ignore GR on this one.

 

[Vorde]

Well ignoring GR whilst trying to calculate black hole information is like asking someone what color a house is without looking at it, but I can address your other point.

Fundamental Particles don't really have a size, when you start getting down to the level where the size of a Fundamental particle becomes non-trivial, the uncertainty principle takes over. Basically a fundamental particle is a point-particle which means it is zero-dimensional (no size), but the uncertainty principle enters in and instead of a single point where the particle definitely is, you have a range of different points where the particle could be located (if that didn't make sense search the forums, someone has explained it better than me). A simple way of looking at it is that as density increases the width of those possible locations of the particle gets smaller. Within a black hole the gravitational force is so great that no force in the universe (that we know of) is strong enough to counter the inward push of gravity. So normally when particles are pushed together, the probability clouds of the particles (meaning the patch where the particle could be) get smaller until some other force (electromagnetic, strong, weak) pushes outwards and balances the force of gravity. However in a black hole, there is no force strong enough to counter the push of gravity so the probability waves of the particles get infinitely small.

 

[dooces]

I hope I am not hijacking a thread here, but it seemed appropriate to ask here rather than creating a new thread...

how do black holes gain mass, or merge with another, if nothing can be observed to enter the BH in finite time? Do they get bigger before anything passes the EH?

Thank you for your time.

 

[Chalnoth]

Why is pressure required to keep the matter collapsing? Did you mean keep the matter FROM collapsing? If something becomes 100% dense (as I believe the singularity to be) and cannot get any denser then how can it collapse any farther? And why would it need pressure to keep it from collapsing?

Yes, I meant keep from collapsing, sorry. If you don't have outward pressure, the inward force of gravity will force the matter to collapse. And no, having the matter simply orbit doesn't work, as there are no stable orbits close to a black hole, let alone inside it.

 

[Chalnoth]

Just to clarify, GR Is well behaved within the event horizon, its only near the singularity that it breaks down. In the case of a rotating or charged black hole, it can be a little worse.

While it is indeed true that General Relativity provides a sensible description of space-time inside the event horizon but outside the singularity, this doesn't mean we can trust it. In order to avoid the singularity, after all, General Relativity has to give an incorrect description of the black hole some distance outside that singularity. How far outside? We don't yet know. My expectation is that it may go as far as the event horizon, because the horizon itself forces quantum effects to have a significant impact on the behavior of the black hole. We think we understand the quantum behavior of the horizon itself. But that makes me doubt any of the non-quantum predictions of what goes on even just inside.

 

[bill alsept]

I didn't understand the second part of your answer. What is orbiting? Basically I am asking how can something collapses after it has already collapsed as far as it can go.

 

[Chalnoth]

I didn't understand the second part of your answer. What is orbiting? Basically I am asking how can something collapses after it has already collapsed as far as it can go.

The only thing that sets how far it can collapse is the supporting pressure.

 

[bill alsept]

I understand pressure is required to supports a balloons surface but not so simple on a bowling ball. Why is pressure needed on a complely solid object?

 

[Chalnoth]

I understand pressure is required to supports a balloons surface but not so simple on a bowling ball. Why is pressure needed on a complely solid object?

Well, consider a chunk of the matter. There will be a force inward caused by the gravitational attraction. If that force is not balanced by something, that force inward will cause the matter to accelerate inward. So if the matter is not collapsing, there must be a force outward to counterbalance the inward force of gravity. That force is a pressure.

 

[zhermes]

While it is indeed true that General Relativity provides a sensible description of space-time inside the event horizon but outside the singularity, this doesn't mean we can trust it. In order to avoid the singularity, after all, General Relativity has to give an incorrect description of the black hole some distance outside that singularity. How far outside? We don't yet know.

That's a really good point. (My personal guess it much closer to the singularity ;)

 

[Chalnoth]

That's a really good point. (My personal guess it much closer to the singularity ;)

For a slightly more detailed answer as to why I think it may need modification even just inside the event horizon, consider this.

From the point of view of the outside observer, an infalling object actually never crosses the event horizon. In fact, Hawking radiation causes the black hole to become smaller before the infalling object ever reaches it. So, what happens to the object if it is never allowed to even cross the event horizon?

Note that if we accept classical General Relativity, from the point of view of the infalling object, it does crash into the singularity in finite time. And this is also what happens even if the black hole is an evaporating black hole that has always existed. Last time I looked this up, however, nobody had managed to figure out what happens in a black hole that forms and evaporates in finite time with General Relativity.

Finally, consider that the Hawking Radiation encodes the information of whatever fell into the black hole, so that the radiation which leaves is physically connected to matter that entered into the black hole.

So my supposition is that the black hole can actually be seen as sort of a collision of matter occurring with an extreme amount of time dilation that is so destructive that it almost perfectly thermalizes any and all matter which enters the collision. This is, however, just supposition.

 

[bill alsept]

Well, consider a chunk of the matter. There will be a force inward caused by the gravitational attraction. If that force is not balanced by something, that force inward will cause the matter to accelerate inward. So if the matter is not collapsing, there must be a force outward to counterbalance the inward force of gravity. That force is a pressure.

Maybe the smallest particles in the universe only have space between them because they are each liberated and going through some repeated cycles of their own. When they are finally corralled and pushed together to the point they can no longer be liberated or move they loose any effect or phenomena they caused before. Could it even be possible that a black hole goes completely cold at the center? And would need no support again leading to the idea that the singularity may have a diameter instead of being a point?

 

[Chalnoth]

Maybe the smallest particles in the universe only have space between them because they are each liberated and going through some repeated cycles of their own. When they are finally corralled and pushed together to the point they can no longer be liberated or move they loose any effect or phenomena they caused before. Could it even be possible that a black hole goes completely cold at the center? And would need no support again leading to the idea that the singularity may have a diameter instead of being a point?

This is a real phenomena, and it happens inside white dwarfs and neutron stars. It's known as degeneracy pressure, because the fermions that make up these particles cannot occupy the same space at the same time. But this degeneracy pressure is limited, and eventually it is simply insufficient to keep these objects from collapsing inward. In the case of the white dwarf, it is the degeneracy pressure of the electrons in the atoms that make up the star. When that pressure gets too great, the electrons combine with the neutrons to form a neutron star. When the neutron degeneracy pressure of the neutron star is insufficient, it collapses to form a black hole. And no amount of pressure can prevent the collapse of the matter inside the event horizon.

 

[bill alsept]

Sorry, I am not trying to beat a dead horse here but I am talking about after neutron degeneracy pressure of the neutron star and any other stages of collapse a body of mass may go through including the stage of converting to a black hole. Which I think is the same as all the other stages where the escape velocity just rises another notch. In this case it rises above the speed of light. But after that stage what stages are there and eventually you get to a particle that are so much smaller than anything else. There would be no other place to collapse to.

 

[Chalnoth]

Sorry, I am not trying to beat a dead horse here but I am talking about after neutron degeneracy pressure of the neutron star and any other stages of collapse a body of mass may go through including the stage of converting to a black hole. Which I think is the same as all the other stages where the escape velocity just rises another notch. In this case it rises above the speed of light. But after that stage what stages are there and eventually you get to a particle that are so much smaller than anything else. There would be no other place to collapse to.

Except that not all matter is fermionic. If the particles collapse to a bosonic state, then they can collapse as far as you like.

 

[Tanelorn]

Chalnoth what other matter is there besides fermions?

 

[Chalnoth]

Chalnoth what other matter is there besides fermions?

At the very least, the photon, gluon, W and Z bosons, and the Higgs boson.

 

[zhermes]

From the point of view of the outside observer, an infalling object actually never crosses the event horizon. In fact, Hawking radiation causes the black hole to become smaller before the infalling object ever reaches it. So, what happens to the object if it is never allowed to even cross the event horizon?

That's not an issue in GR. First, for all practical purposes the event horizon is going to increase is size from the newly accreted matter, not decrease in size---only the smallest of black-holes (with no known formation mechanism) decrease in size at all.
Second, the same argument would apply to the classic undergrad question 'how does the black-hole increase in mass at all?' --- which is a non-issue. The object crosses the event horizon without a problem, its just never observed.

Note that if we accept classical General Relativity, from the point of view of the infalling object, it does crash into the singularity in finite time. And this is also what happens even if the black hole is an evaporating black hole that has always existed. Last time I looked this up, however, nobody had managed to figure out what happens in a black hole that forms and evaporates in finite time with General Relativity.

Yes, the singularity is of course an issue---but I don't see how adding a finite-aged black-hole complicates the issue. And note that you don't have evaporation with just general relativity.

Finally, consider that the Hawking Radiation encodes the information of whatever fell into the black hole, so that the radiation which leaves is physically connected to matter that entered into the black hole.

Again, I don't see an issue here.

So my supposition is that the black hole can actually be seen as sort of a collision of matter occurring with an extreme amount of time dilation that is so destructive that it almost perfectly thermalizes any and all matter which enters the collision. This is, however, just supposition.

I don't follow what you're saying.

 

[zhermes]

Sorry, I am not trying to beat a dead horse here but I am talking about after neutron degeneracy pressure of the neutron star and any other stages of collapse a body of mass may go through including the stage of converting to a black hole. ... But after that stage what stages are there and eventually you get to a particle that are so much smaller than anything else. There would be no other place to collapse to.

This is completely irrelevant as has already been stated many times. If you still don't understand, you should read a GR textbook. The nature of the material within the event horizon doesn't matter in general relativity. There is no such thing as 'a particle so much smaller than anything else'---you're argument is based on the premise that there is a fundamentally small thing, which cannot get smaller; you are then using that as an argument for the same point.

 

[Chalnoth]

Yes, the singularity is of course an issue---but I don't see how adding a finite-aged black-hole complicates the issue. And note that you don't have evaporation with just general relativity.

The potential complication is that it is apparently unknown whether or not a singularity would form for a finite-aged black hole (in this case singularity simply meaning dense clump of matter at the center, instead of a mathematical singularity, since we'd be talking about a real black hole). That is, the time dilation may be so severe that the matter inside the event horizon just doesn't have enough time to collapse any significant amount before the black hole evaporates.

And yeah, obviously I was talking about a semi-classical black hole with regard to evaporation, which uses General Relativity to define the space-time but adds an evaporation mechanism.

 

[zhermes]

The potential complication is that it is apparently unknown whether or not a singularity would form for a finite-aged black hole (in this case singularity simply meaning dense clump of matter at the center, instead of a mathematical singularity, since we'd be talking about a real black hole). That is, the time dilation may be so severe that the matter inside the event horizon just doesn't have enough time to collapse any significant amount before the black hole evaporates.

This is not an issue. Formation of black-holes and singularities has been thoroughly studied, by Papapetrou, Thorne, Penrose... Teukolsky I think. Again, in all astrophysically significant cases, evaporation can't occur----absorption of the CMB is far more rapid than the production of hawking radiation (and I can't recall for sure, but I think even very low ambient density environments, the bondi accretion is also more rapid than Hawking Radiation).

 

[Chalnoth]

This is not an issue. Formation of black-holes and singularities has been thoroughly studied, by Papapetrou, Thorne, Penrose... Teukolsky I think.

Well, admittedly I haven't looked into this in great detail myself. But in this case I'm going off of my GR professor, Steve Carlip, who I think is generally quite good on this stuff. As far as I know, we're still a long way from really examining what GR has to say here for anything beyond the absolute simplest case. My understanding was that the only sort of black hole formation we could produce was due to symmetric infalling spherical shells, and that is a highly non-physical situation.

Again, in all astrophysically significant cases, evaporation can't occur----absorption of the CMB is far more rapid than the production of hawking radiation (and I can't recall for sure, but I think even very low ambient density environments, the bondi accretion is also more rapid than Hawking Radiation).

Well, sure, but those accretion processes will all end in far, far less time than the expected black hole evaporation rate anyway. We're talking roughly 10^{66} to 10^{100} year timescales here. So I don't quite understand what this has to do with my point that we may not know much of anything about what's going on inside the black hole's event horizon.

 

[Tanelorn]

At the very least, the photon, gluon, W and Z bosons, and the Higgs boson.

Chalnoth, are Bosons or force carriers conidered what is loosely called "ponderable matter". I am quite prepared to be wrong about this I just thought they werent.

 

[Chalnoth]

Chalnoth, are Bosons or force carriers conidered what is loosely called "ponderable matter". I am quite prepared to be wrong about this I just thought they werent.

Well, they are either moving at the speed of light or are unstable. But when they are inside the event horizon of a black hole, moving at the speed of light doesn't prevent collapse, and the extreme space-time curvature may potentially make the W and Z bosons stable, in an analogous way to how the incredibly high pressure inside a neutron star makes neutrons stable.

Edit: Of course, this almost certainly isn't enough to produce a degenerate bosonic state at the center of a black hole, because you also have to get rid of the baryons, and baryon number is a conserved quantity in known physics. So we would probably need some beyond-standard-model interactions to get into a degenerate bosonic state, and that may open the door for still more bosons.

 

[zhermes]

It was specifically in reference to your comment that:

That is, the time dilation may be so severe that the matter inside the event horizon just doesn't have enough time to collapse any significant amount before the black hole evaporates.

Those studies have shown singularity formation in finite coordinate (and proper) time---but you're right, I'm not sure exactly how long (but I think its on the order of a dynamical time), and in how diverse situations; good keeping me on my toes.

But going back to the initial point; the event horizon can definitely form stably. We agree that the singularity itself is completely questionable---so that part doesn't really matter. My overall argument is that we are really really confident event horizons can form; and quantum mechanics (string theory etc etc) only suggest GR breaks something like 50 orders of magnitude closer to the center of the BH than the event horizon... so there doesn't seem to be a reason to expect GR to break near the EH...

(Unless you're looking at a near-extremal kerr black-hole---which we believe exist---in which case the singularity itself can be very near the event horizon.

 

[bill alsept]

The nature of the material within the event horizon doesn't matter in general relativity.

Mabey not in GR but it does matter to the anatomy of black holes and the point of this conversation. GR has trouble explaining some things and obviously black holes are one of them.

There is no such thing as 'a particle so much smaller than anything else'---

How can anyone say there are no particles smaller. Didn,t they original name the atom becuase they thought it could not be divided anymore? We know quarks are made from something smaller, maybe that will be the next think we discover.

 

[zhermes]

Mabey not in GR but it does matter to the anatomy of black holes and the point of this conversation. GR has trouble explaining some things and obviously black holes are one of them.

I've already told you the answer according to string theory; nothing else applies.

How can anyone say there are no particles smaller. Didn,t they original name the atom becuase they thought it could not be divided anymore? We know quarks are made from something smaller, maybe that will be the next think we discover.

Quarks are not made of something smaller---they are fundamental particles. Fundamental particles are points---i.e. no finite size--and thus, again, nothing can be smaller. Additionally the concept of 'size' of a particle doesn't really apply in this regime (unless you're talking about string theory), and as I said before, in that case you have a Planck-sized mass at the center of the (schwarschild) black-hole.

 

[bill alsept]

I've already told you the answer according to string theory; nothing else applies.

I'm sorry but that sounds to much like a religious answer. The nature of the material within the event horizon would matter. If like you say it doesn't matter to GR then who cares. It’s still there and would matters to everything else.

Why do black holes need to be so mysterious? Why can't they just be like every other mass. Just because g has an escape velocity faster than light who cares. Everything is still there we just can't see it. If we ever find a way to see black holes I would bet that the body of the black hole has an actual diameter and that its growing.

Quarks are not made of something smaller---they are fundamental particles. Fundamental particles are points---i.e. no finite size--and thus, again, nothing can be smaller. Additionally the concept of 'size' of a particle doesn't really apply in this regime (unless you're talking about string theory), and as I said before, in that case you have a Planck-sized mass at the center of the (schwarschild) black-hole.

You can't say quarks are fundamental without proof. We may one day find that there are many smaller levels. I think one clue that quarks are made of smaller parts is that quarks react with other quarks. Whatever force they use to accomplish this may come from within each one so they could have some sub parts or moving parts to cause these forces, fields or phenomenon. Just a thought

 

[zhermes]

Consult the PF Forums rules on overly speculative posts. The burden is not on me to prove the established canon, nor to disprove your personal theory of the universe.

 

[twofish-quant]

You can't say quarks are fundamental without proof.

Mathematicians deal with proof. Physicists deal with evidence.

The reason we know that protons are not point particles is that if you ram two protons together you get scattering angles that are consistent with sub-structure. If you ram quarks and electrons together, you get scattering that is consistent with point particles.

Also thermodynamics and QM provide some limits on the types of viable preon models.

http://en.wikipedia.org/wiki/Preon

Essentially if quarks had substructure, the Heisenberg uncertainty principle would cause enough momentum uncertainty to be larger than the rest mass of the particle. There are also thermodynamic limits. If you have substructure you change the statistics of matter and so that changes its thermal properties.

There are ways of getting around those limits, but right now the experimental data is consistent with non-substructure and there are some very strong limits as to what theories are consistent with observations.

We may one day find that there are many smaller levels.

We've looked. We haven't found anything, and we have evidence that there is nothing there to be found.

I think one clue that quarks are made of smaller parts is that quarks react with other quarks. Whatever force they use to accomplish this may come from within each one so they could have some sub parts or moving parts to cause these forces, fields or phenomenon. Just a thought

Look up "preon"

 

[twofish-quant]

How can it collapse further and why does it have to? Can't a black hole be so dense that there is no space left inside? An area filled 100% complete with the smallest partials the universe has to offer. There would be no more area to collapse to.

Won't work. What happens is that as you increase the gravity, the number of possible energy states for the particles increase so that the pressure necessary to keep the particles from collapsing disappears.

This is a general argument that works with any set of particles.

I realize my original question most likely cannot be answered because we don’t know how small those first particles are or how many have accumulated in the black hole.

Doesn't matter, the smaller the particles, the faster the collapse. As long as special relativity is correct, then given enough gravity, things are unstable to collapse. If special relativity is wrong, then you tell me what the rules are.

 

[twofish-quant]

I understand pressure is required to supports a balloons surface but not so simple on a bowling ball. Why is pressure needed on a complely solid object?

Pressure is what makes a solid object a solid.

 

[bill alsept]

Mathematicians deal with proof. Physicists deal with evidence.

The reason we know that protons are not point particles is that if you ram two protons together you get scattering angles that are consistent with sub-structure. If you ram quarks and electrons together, you get scattering that is consistent with point particles.

Also thermodynamics and QM provide some limits on the types of viable preon models.

http://en.wikipedia.org/wiki/Preon

Essentially if quarks had substructure, the Heisenberg uncertainty principle would cause enough momentum uncertainty to be larger than the rest mass of the particle. There are also thermodynamic limits. If you have substructure you change the statistics of matter and so that changes its thermal properties.

There are ways of getting around those limits, but right now the experimental data is consistent with non-substructure and there are some very strong limits as to what theories are consistent with observations.



We've looked. We haven't found anything, and we have evidence that there is nothing there to be found.



Look up "preon"

Thank You for good answers.

 

[twofish-quant]

Maybe the smallest particles in the universe only have space between them because they are each liberated and going through some repeated cycles of their own. When they are finally corralled and pushed together to the point they can no longer be liberated or move they loose any effect or phenomena they caused before.

That makes things worse.

The reason that solids are solids is because you've filled up all of the available energy states and to kick a particle into a higher energy state takes a lot of energy. If you create additional particles, then you increase the number of energy states, and things become softer.

One way of thinking about this is imagine getting hit by a brick. And getting hit by a pile of sand. Because there are more ways that the sand can move, it's a lot softer, and this sort of thing happens at the subatomic level.

Could it even be possible that a black hole goes completely cold at the center? And would need no support again leading to the idea that the singularity may have a diameter instead of being a point?

When you have no evidence then anything is possible. It's possible that the black hole goes completely cold. It's also possible that the singularity turns into trained dancing penguins. When you don't know, you don't know.

 

[twofish-quant]

Sorry, I am not trying to beat a dead horse here but I am talking about after neutron degeneracy pressure of the neutron star and any other stages of collapse a body of mass may go through including the stage of converting to a black hole. Which I think is the same as all the other stages where the escape velocity just rises another notch. In this case it rises above the speed of light. But after that stage what stages are there and eventually you get to a particle that are so much smaller than anything else. There would be no other place to collapse to.

Small particles makes things collapse faster. The reason things stop collapsing is that you've filled up all of the energy states. Once you increase gravity, the energy levels change so that you have empty stops that open up. If you create new particles, the number of energy states increases even more so things will collapse faster.

 

[twofish-quant]

Why do black holes need to be so mysterious? Why can't they just be like every other mass.

I don't think that black holes are mysterious. The singularity in the middle of a black hole, on the other hand...

Just because g has an escape velocity faster than light who cares. Everything is still there we just can't see it. If we ever find a way to see black holes I would bet that the body of the black hole has an actual diameter and that its growing.

There's a basic problem.

Suppose you have an infinitely stiff stick. I push the stick on earth, then instantly the end of the stick on the moon moves. Uh. Oh. I just transmitted information faster than light, and that's a no-no. So the speed of light puts limits on how stiff something is.

So let's think of something else. I hit a table. The atoms in the table change directions and creates a force that pushes back. Now let's suppose I have something that is traveling near the speed of light. Since I can't push it past the speed of light, if I push on something that near the speed of light, it doesn't change speed very much. No matter how much energy I put into it, it won't go past the speed of light.

This presents a problem. Suppose I have a table and the particles in it are vibrating at close to the speed of light. If I hit that table, the particles won't react, and so I won't get a force in the other direction. So if I hit a table with particles moving at close to the speed of light, then my hand will fall through the table, and since the particles don't react with each other, solid objects are impossible once you have particles that are moving at close to light speed.

So the net result is that it doesn't matter what the table is made of. It doesn't matter how many particles there are. Once I crush the table enough so that the particles are moving near light speed, it will cease acting like a solid object. Having smaller particles makes the problem *worse* since it's easier to push a particle to light speed.

This means that if Einstein is right, things will get crushed to nothing. Now this leads to some absurd situations, so we are pretty sure he is wrong. The trouble is that no one knows *how* he is wrong.

 

[bill alsept]

I don't think that black holes are mysterious. The singularity in the middle of a black hole, on the other hand...
There's a basic problem.

Suppose you have an infinitely stiff stick. I push the stick on earth, then instantly the end of the stick on the moon moves. Uh. Oh. I just transmitted information faster than light, and that's a no-no. So the speed of light puts limits on how stiff something is.

So let's think of something else. I hit a table. The atoms in the table change directions and creates a force that pushes back. Now let's suppose I have something that is traveling near the speed of light. Since I can't push it past the speed of light, if I push on something that near the speed of light, it doesn't change speed very much. No matter how much energy I put into it, it won't go past the speed of light.

This presents a problem. Suppose I have a table and the particles in it are vibrating at close to the speed of light. If I hit that table, the particles won't react, and so I won't get a force in the other direction. So if I hit a table with particles moving at close to the speed of light, then my hand will fall through the table, and since the particles don't react with each other, solid objects are impossible once you have particles that are moving at close to light speed.

So the net result is that it doesn't matter what the table is made of. It doesn't matter how many particles there are. Once I crush the table enough so that the particles are moving near light speed, it will cease acting like a solid object. Having smaller particles makes the problem *worse* since it's easier to push a particle to light speed.

This means that if Einstein is right, things will get crushed to nothing. Now this leads to some absurd situations, so we are pretty sure he is wrong. The trouble is that no one knows *how* he is wrong.

Thank you, I like the way you describe things. Very insightful and interesting. I too think there is a problem and would like to discuss this more but it seems I get scolded every time I even begin to get speculative. Thanks again

 

[bill alsept]

Small particles makes things collapse faster. The reason things stop collapsing is that you've filled up all of the energy states. Once you increase gravity, the energy levels change so that you have empty stops that open up. If you create new particles, the number of energy states increases even more so things will collapse faster.

Can you explain this one another way?
Thanks

 

[bill alsept]

There's a basic problem.

Suppose you have an infinitely stiff stick. I push the stick on earth, then instantly the end of the stick on the moon moves. Uh. Oh. I just transmitted information faster than light, and that's a no-no. So the speed of light puts limits on how stiff something is.

I know this is speculating (not overly I hope) but what if the speed of light was not the end all. What if that’s all the faster it could go because of some unknown resistance. It appears gravity out does the speed of light why not other things?