State of "matter" of a singularity

[gatewood]

Just a fun question: what state of energy/matter, could it be argued, that a gravitational singularity is in?

I would say that, it broke down to the most fundamental form of energy. Could it be said that, it is an extremely exotic form of atom?

Edited June 21, 2021 by gatewood

[swansont]

It's not clear that gravitational singularities exist, and we don't have the physics to describe such things.

"fundamental form of energy" doesn't make sense. 

 

 

[exchemist]

1 hour ago, gatewood said:

Just a fun question: what state of energy/matter, could it be argued, that a gravitational singularity is in?

I would say that, it broke down to the most fundamental form of energy. Could it be said that, it is an extremely exotic form of atom?

Energy is a property of a physical system of some sort. It is not "stuff": you can't have a jug of energy. So it becomes pretty hard to see how a singularity can have energy. It would have to be a system, and that would prevent it being a singularity. 

[gatewood]

2 hours ago, swansont said:

It's not clear that gravitational singularities exist, and we don't have the physics to describe such things.

"fundamental form of energy" doesn't make sense.

ohhh... please, cut the chase, we all know gravitational singularities are basically a placeholder for where our understanding of physics breaks down.

What I mean to say/ask: (fun question) what would you think we'll see if we could compress , say, 10 solar masses to the size of an atom (not an infinitesimally small volume)? Suppose there where no such thing as a schwartschild radius, but we could still compress stellar amounts of matter down to atomic/subatomic scales and also still observe it.

[Bufofrog]

31 minutes ago, gatewood said:

Suppose there where no such thing as a schwartschild radius, but we could still compress stellar amounts of matter down to atomic/subatomic scales and also still observe it.

Then we are in a made up universe, and you need a better description of this made up universe to answer the question.

[exchemist]

1 hour ago, gatewood said:

ohhh... please, cut the chase, we all know gravitational singularities are basically a placeholder for where our understanding of physics breaks down.

What I mean to say/ask: (fun question) what would you think we'll see if we could compress , say, 10 solar masses to the size of an atom (not an infinitesimally small volume)? Suppose there where no such thing as a schwartschild radius, but we could still compress stellar amounts of matter down to atomic/subatomic scales and also still observe it.

You mean, what would we see if the laws of physics were not what they are? Surely that would depend on what they were instead, wouldn't it?  

[gatewood]

holy ppl... im merely asking, what might you think happens to matter, as it compresses, beyond neutron degeneracy. E.g. what state of matter could it be said it is in... if at any? (like the hypothetical quark stars).

Edited June 21, 2021 by gatewood

[beecee]

31 minutes ago, gatewood said:

holy ppl... im merely asking, what might you think happens to matter, as it compresses, beyond neutron degeneracy. E.g. what state of matter could it be said it is in... if at all? (like the hypothetical quark stars).

OK, my shot at this, based on much reputable material that I have read, and my understanding thereof.

As matter collapses, it reaches a point [radius] we call the Schwarzchild radius/limit at which further collapse is compulsory. That coincides with what we know as the EH of a BH, all according to GR. The collapse continues until it reaches the quantum/Planck level, at which GR and our known laws of physics fail us. During this process, all matter is broken down into its most fundamental parts.

The question from this point of reaching the quantum/Planck level, is whether such collapse continues to a singularity point of infinite density and spacetime curvature. This is generally rejected by most physicists and cosmologists  for obvious reasons. Which leaves us with matter in some form or other, residing at or just below the quantum/Planck level...a surface of sorts if you will, which is still called a singularity as defined by where GR and our laws of physics fail us. Consequently the exact nature of what resides there is unknown.   

Edited June 21, 2021 by beecee

[exchemist]

52 minutes ago, gatewood said:

holy ppl... im merely asking, what might you think happens to matter, as it compresses, beyond neutron degeneracy. E.g. what state of matter could it be said it is in... if at any? (like the hypothetical quark stars).

People theorise about "quark matter", I think, viz. a form of degenerate matter in which neutrons lose their identity and one has just quarks. But I know nothing about this. I gather we don't know enough about the strong force to model it very well.  

[MigL]

WE know of no mechanism that will stop gravitational collapse after neutron degeneracy fails.

So called 'quark stars' would actually be neutrons packed so closely, that the quarks, that comprise them, are 'free'.

[gatewood]

2 hours ago, MigL said:

WE know of no mechanism that will stop gravitational collapse after neutron degeneracy fails.

So called 'quark stars' would actually be neutrons packed so closely, that the quarks, that comprise them, are 'free'.

Sure, but the question doesn't need it.

Say we paused a black hole just after its schwarzschild radius gobbled all the core of the star that formed it, and, hypothetically, we could take a peek inside. What would we see? What would matter compressed down, further than neutron (or quark) degeneracy, would be like?

I mean, the core of my question would be: all that fell inside a black hole... still exists in some form? And if so, what you think it that form is? A Bunch of elementary particles? Energy resulting from annihilated particles? A bunch of photons and neutrinos?

Edited June 22, 2021 by gatewood

[storyteller]

11 hours ago, gatewood said:

Just a fun question: what state of energy/matter, could it be argued, that a gravitational singularity is in?

I would say that, it broke down to the most fundamental form of energy. Could it be said that, it is an extremely exotic form of atom?

 

2 hours ago, gatewood said:

Sure, but the question doesn't need it.

Say we paused a black hole just after its schwarzschild radius gobbled all the core of the star that formed it, and, hypothetically, we could take a peek inside. What would we see? What would matter compressed down, further than neutron (or quark) degeneracy, would be like?

I mean, the core of my question would be: all that fell inside a black hole... still exists in some form? And if so, what you think it that form is? A Bunch of elementary particles? Energy resulting from annihilated particles? A bunch of photons and neutrinos?

 

It is currently not possible to know what happen to any object that get pull into gravitational singularity, like stellar black holes, since no observations are capable of observing beyond the Event Horizon.

If the gravitational forces are greater as astrophysicists say they are about the blackholes, then the probability of them retaining their shapes and forms would be slim...but then again, it is really impossible to say for certain, since the lack of observations of the black hole’s surface.

[Kartazion]

4 hours ago, gatewood said:

Say we paused a black hole just after its schwarzschild radius gobbled all the core of the star that formed it, and, hypothetically, we could take a peek inside. What would we see? What would matter compressed down, further than neutron (or quark) degeneracy, would be like?

I mean, the core of my question would be: all that fell inside a black hole... still exists in some form? And if so, what you think it that form is? A Bunch of elementary particles? Energy resulting from annihilated particles? A bunch of photons and neutrinos?

As one might imagine it, the singularity is the convergence of dimensions at a point.
The reduction of the field of action of the space time, annihilates the functioning of the elements composing the dimession.
It is true that for the big bang and if we had to represent this singularity, the evolution of the energy, gravity and the dimension x, y, z, t, or more, will start from a zero point.
It comes back to asking if this value of zero at rest would have a form of matter (the energy would surely be maximum), for indeed the formation of baryonic matter cannot exist, not even the photon during the first moment of primordial nucleosynthesis, either after a primitive expansion of sigularity.
 

[exchemist]

6 hours ago, gatewood said:

Sure, but the question doesn't need it.

Say we paused a black hole just after its schwarzschild radius gobbled all the core of the star that formed it, and, hypothetically, we could take a peek inside. What would we see? What would matter compressed down, further than neutron (or quark) degeneracy, would be like?

I mean, the core of my question would be: all that fell inside a black hole... still exists in some form? And if so, what you think it that form is? A Bunch of elementary particles? Energy resulting from annihilated particles? A bunch of photons and neutrinos?

As far as I'm aware, we  don't have a theory for that. As quarks are the most elementary unit of matter we know of, I doubt that we have anything on which to base any speculations as to  whether or not they might be decomposable into something "more" fundamental.  Though I'd be interested if any physicists have anything to add on that.

 

Edited June 22, 2021 by exchemist

[beecee]

3 hours ago, Kartazion said:

As one might imagine it, the singularity is the convergence of dimensions at a point.

Most Cosmologists/Physicists reject the singularity as defined by infinite density and infinite spacetime curvature. The only singularity is that as defined by the failure of GR and our laws of physics.

6 hours ago, storyteller said:

It is currently not possible to know what happen to any object that get pull into gravitational singularity, like stellar black holes, since no observations are capable of observing beyond the Event Horizon.

While it is certainly true that we can never by definition see inside the EH of a BH, observations of the behavior of orbiting matter and accretion disks, lead us to the belief that "gravitationally completely collapsed objects", henceforth known as BH's are the only way to explain such behavior, and as they are also a prediction of GR, plus being supported by the discovery of gravitational radiation, not to mention the image as phoyographed by the "Evet Horizon telescope" the GR BH model can be reasonably accepted.

6 hours ago, storyteller said:

If the gravitational forces are greater as astrophysicists say they are about the blackholes, then the probability of them retaining their shapes and forms would be slim...but then again, it is really impossible to say for certain, since the lack of observations of the black hole’s surface.

Well once the balance of radiative forces and gravitational forces cease, gravity takes over, period...and as mentioned before, once the Schwarzchild radius/limit is reached, further collapse as dictated by GR, is compulsory...at least up to the quantum/Planck region where GR and all known physical laws fail us. [see post 

13 hours ago, beecee said:

OK, my shot at this, based on much reputable material that I have read, and my understanding thereof.

As matter collapses, it reaches a point [radius] we call the Schwarzchild radius/limit at which further collapse is compulsory. That coincides with what we know as the EH of a BH, all according to GR. The collapse continues until it reaches the quantum/Planck level, at which GR and our known laws of physics fail us. During this process, all matter is broken down into its most fundamental parts.

The question from this point of reaching the quantum/Planck level, is whether such collapse continues to a singularity point of infinite density and spacetime curvature. This is generally rejected by most physicists and cosmologists  for obvious reasons. Which leaves us with matter in some form or other, residing at or just below the quantum/Planck level...a surface of sorts if you will, which is still called a singularity as defined by where GR and our laws of physics fail us. Consequently the exact nature of what resides there is unknown.   

In essence we can reasonably accept that BH's are essentially just curved spacetime [ignoring in-pouring matter/energy] with a possible surface of sorts, at or below the quantum/Planck level. A validated QGT may in time, reveal more and desirably, explain BH's  more realistically without any need for singularities of an infinite dense and curved nature.

Edited June 22, 2021 by beecee

[MigL]

14 hours ago, storyteller said:

Say we paused a black hole just after its schwarzschild radius gobbled all the core of the star that formed it, and, hypothetically, we could take a peek inside. What would we see?

It is my understanding that once neutron degeneracy fails, the collapse is almost immediate.
Further, it starts from the inside, and moves outward.
IOW, the Event Horizon ( Schwartzschild radius for a non rotating, non charged, BH ) starts at its center and grows outward, as the outer extremes of the collpsing star are less dense than the center. The outer extremes essentially 'fall' into the Event Horizon, which grows as a result.

So, I guess, if you looked 'inside' a gravitationally collapsing neutron star, you would see a growing Event Horizon.
 

[beecee]

2 hours ago, MigL said:

It is my understanding that once neutron degeneracy fails, the collapse is almost immediate.
Further, it starts from the inside, and moves outward.
IOW, the Event Horizon ( Schwartzschild radius for a non rotating, non charged, BH ) starts at its center and grows outward, as the outer extremes of the collpsing star are less dense than the center. The outer extremes essentially 'fall' into the Event Horizon, which grows as a result.

So, I guess, if you looked 'inside' a gravitationally collapsing neutron star, you would see a growing Event Horizon.
 

Good obviously sensible point, which I have never really thought about. Thanks.

[storyteller]

3 hours ago, MigL said:

It is my understanding that once neutron degeneracy fails, the collapse is almost immediate.
Further, it starts from the inside, and moves outward.
IOW, the Event Horizon ( Schwartzschild radius for a non rotating, non charged, BH ) starts at its center and grows outward, as the outer extremes of the collpsing star are less dense than the center. The outer extremes essentially 'fall' into the Event Horizon, which grows as a result.

So, I guess, if you looked 'inside' a gravitationally collapsing neutron star, you would see a growing Event Horizon.
 

 

That’s insightful and very helpful reply.

But what you quoted, isn’t my reply/post, it’s gatewood’s comment.

It is only my 2nd day as member, but it would seem there is bug in “quote” function.

[swansont]

13 minutes ago, storyteller said:

It is only my 2nd day as member, but it would seem there is bug in “quote” function.

Yes, there is. One hopes it gets fixed by the people that sell the software

[MigL]

My apologies.
I may have quoted a quote.

[storyteller]

8 hours ago, MigL said:

My apologies.
I may have quoted a quote.

No apologies needed.

your post was informative regardless who you were replying to.

[Fly135]

Not sure if there is a rule about replying to a year old topic, but...  If protons and neutrons are made up of quarks that get mass from their kinetic energy.  Then you wouldn't you expect the neutrons to lose mass when the quarks are compresses into a singularity.

Edited August 12, 2022 by Fly135

[Mitcher]

My guess is space and time would ultimately degenerate and transform under rules we still don't know about. According to Pierre Petit there is no such thing as the inside of a BH, it merely went outside the continuum as per the original view of Schwarschild, which has been later corrupted. PP explains it very well.

[Markus Hanke]

19 hours ago, Mitcher said:

it merely went outside the continuum

What does this mean?

19 hours ago, Mitcher said:

as per the original view of Schwarschild, which has been later corrupted.

Nothing has been ‘corrupted’, it’s just that now, a century later, we have a much better understanding of the foundations of GR than Schwarzschild (or any of his contemporaries) would have had. There was confusion about this only because the model was brand new back then, and it took time to figure things out. Nowadays we are in a much better position.

In his original paper, Schwarzschild used a coordinate system that had its origin at the event horizon, so r=0 meant the horizon surface. However, this does not at all mean that there is nothing beyond the horizon, because in GR the choice of coordinates is arbitrary and has no physical significance. Schwarzschild used this convention simply because it made his particular way of deriving the solution mathematically easier. A consequence of this choice is that large parts of the spacetime aren’t covered by any coordinate patch, so, in his notation, there are physical events that cannot be labled by any coordinate. But again, that’s just a convention without physical significance. You can rectify this simply by choosing a different coordinate system - which does not change anything about the actual geometry of the spacetime. This is why there are so many seemingly different metrics (Novikov, Kruskal-Szekeres, Aichlburg-Sexl, etc etc) which all describe the same physical spacetime.

To see whether the event horizon is a physical singularity (as opposed to just a coordinate one), and what the nature of spacetime beyond the horizon is, you can use tools that do not depend on the choice of coordinate system at all - such as invariants of the curvature tensors. That way, it’s trivially easy to show that, in classical GR, the horizon as well as all of spacetime in the interior right down to the singularity is in fact perfectly smooth and regular, just like anywhere outside the horizon. This is a standard exercise in pretty much any graduate GR course.

[Mitcher]

7 hours ago, Markus Hanke said:

What does this mean?

Just a layman way of saying it is outside the manifold. In plain words, a hole, or a throat, appears on the space-time fabric as with a Flamm surface, which is not contractile and has no center.

7 hours ago, Markus Hanke said:

What does this mean?

Nothing has been ‘corrupted’, it’s just that now, a century later, we have a much better understanding of the foundations of GR than Schwarzschild (or any of his contemporaries) would have had. There was confusion about this only because the model was brand new back then, and it took time to figure things out. Nowadays we are in a much better position.

In his original paper, Schwarzschild used a coordinate system that had its origin at the event horizon, so r=0 meant the horizon surface. However, this does not at all mean that there is nothing beyond the horizon, because in GR the choice of coordinates is arbitrary and has no physical significance. Schwarzschild used this convention simply because it made his particular way of deriving the solution mathematically easier. A consequence of this choice is that large parts of the spacetime aren’t covered by any coordinate patch, so, in his notation, there are physical events that cannot be labled by any coordinate. But again, that’s just a convention without physical significance. You can rectify this simply by choosing a different coordinate system - which does not change anything about the actual geometry of the spacetime. This is why there are so many seemingly different metrics (Novikov, Kruskal-Szekeres, Aichlburg-Sexl, etc etc) which all describe the same physical spacetime.

To see whether the event horizon is a physical singularity (as opposed to just a coordinate one), and what the nature of spacetime beyond the horizon is, you can use tools that do not depend on the choice of coordinate system at all - such as invariants of the curvature tensors. That way, it’s trivially easy to show that, in classical GR, the horizon as well as all of spacetime in the interior right down to the singularity is in fact perfectly smooth and regular, just like anywhere outside the horizon. This is a standard exercise in pretty much any graduate GR course.

Thanks for your explanations, indeed Schzartchild used r as a simple parameter which has been wrongly understood to be a radius but in his mind it was never the case at all. According to Weyl, when M grows bigger than 2.5 solar masses then the proper mass is inverted. Weyl wrote his article in 1917 but was translated only 90 years or so later so Oppenheimer and Wheeler had not read it when they invented the singularity-based BH model many years later. According to Schwarschild, if r becomes smaller than Rs then the ds squared becomes negative, hence we are outside the hypersurface. Tolman and Oppenheimer only forgot about the preriquisite condition r > Rs (that’s what I mentionned as "corrupted"). IMO only a mathematical singularity can make sense, believing in a physical one is like believing flat oceans could have no borders. So yes, Kruskal and Oppenheimer theorized time and space directions inversion to allow for time to flow endlessly into the singularity but, as for the flat Earth borders, it seems far from substantiated.