Can Mass Exist in a Singularity?

[bayan]

Hi all.

I was interested to know if any mass can exist in singularity? Personaly I think I cannot because there are no dimentions or anything, but a friend of mine says that mass can exist(he is not really a physisit and hasn't got much of a knowledge)?

Who is right?

 

[Chronos]

A singularity has all the typical signs of possessing mass. It bends light, stars orbit it, etc. Mass cannot disappear without a trace without tossing most of modern physics into the trash can. Aside from that, singularities are mathematical artifacts. Most modern theorists do not believe they are dimensionless points.

 

[bayan]

so does this mean that mass can exist in a black hole? Are there any dimensions in a black hole?

 

[James R]

Black holes have mass. If our Sun suddenly turned into a black hole, the Earth would continue to orbit the hole in exactly the same way it currently orbits the sun. The effect of the black hole's mass is the same as any other equal mass, more or less - so long as you're outside the event horizon.

 

[DB]

Too add a little, James mentioned the effect of a black hole is the same as any other equal mass. In general relativity, a key concept to understanding a black hole is spacetime fabric. Let's take a neutron star for example. A star with mass $x$ and density $y_{g/cm^3}$, explodes as a supernova, and forms a neutron star. Well this neutron star will still conserve it's mass $x$ (a little bit of mass is lost as the star's outer layers are blasted off, but it's not important now), but, it's density will now be around $y*10^{15}_ {g/cm^3}$. Atoms are so tightly packed that the protons and electrons merge into neutrons! So the denser a mass, the more spacetime is curved, the more spacetime is curved the stronger the gravitational force. A black hole is the same way. I used a neutron star because we know more of the numbers than we do a black hole. Right now all we say is a black hole is infinitly dense.
So, in my opinon, black holes should have mass.

 

[kirovman]

Black holes have mass. If our Sun suddenly turned into a black hole, the Earth would continue to orbit the hole in exactly the same way it currently orbits the sun. The effect of the black hole's mass is the same as any other equal mass, more or less - so long as you're outside the event horizon.

I would extent that to: so long as you are outside the equivilant radius of the surface of the equivilant mass.
The event horizon of a sun-massed black hole would be ~1km in radius.
But the gravitational effects would start to differ between the two objects as you pass the equivilant distance of the sun's radius.

-hmm hope my wording is ok to understand

 

[SpaceTiger]

From what I understand, the following quantities will COMPLETELY describe a black hole (theoretically):

- mass
- angular momentum
- charge

That is excluded to their observable properties, of course. Inside the event horizon, all bets are off.

 

[bayan]

I am still not too clear about it as my english lacks abit. So would a mass exist inside a black hole? i.e. Could a mass travel through a black hole?

 

[hellfire]

Actually every black hole has mass, as was already explained. May be you mean ‘matter’ instead of ‘mass’. Black holes form from matter, i.e. fermions (particles with half-integer spin), but they cannot contain any fermions at all, because fermions are destroyed during the gravitational collapse into the singularity. If they would not be destroyed, the Pauli exclusion principle would be violated. The Pauli exclusion principle states that two fermions cannot occupy the same quantum state, or the same place (and the singularity is just one point in space).

 

[primal schemer]

I can`t think of any way that something with mass could travel through a black hole. Any object that enters a black hole will feel a huge gravitational pull and stay in the black hole.

Correct me if I`m wrong, but I think it would require an infinite amount of energy to move a massive object out of a black hole.

 

[Billy T]

Black holes have mass. If our Sun suddenly turned into a black hole, the Earth would continue to orbit the hole in exactly the same way it currently orbits the sun. The effect of the black hole's mass is the same as any other equal mass, more or less - so long as you're outside the event horizon.

I understand the point you are trying to make, and agree, but think you may be wrong for two reasons:

1) The gravitational energy released by the suddent collapse of the sun, which, as I am sure you know if you are the same "Jame R" I know and greatly respect from another forum, is not massive enough to become a black hole, but even by just becoming a neutron star/ pulsar it would still blast a lot of energy into space. Earth's side near the sun, certainly the atmosphere, but I bet a lot of the dirt as well, would be blasted into space, changing the orbit of what was left, if anything.

2) Most of the energy released would not impinge upon any planet, but leave our solar system. Good old E=Mc2 would indicate that the residual "sun" was less masive and the Earth (neglecting point 1 above) would have too much orbit veolocity for current distance from the sun. I.e. it would suddenly be in a more ellipetical orbit climbing towards its new appogee.

If either 1 or 2 is correct (and I think both are) the Earth's max distance from the sun would very significantly increase.

 

[Billy T]

From what I understand, the following quantities will COMPLETELY describe a black hole (theoretically):

- mass
- angular momentum
- charge

That is excluded to their observable properties, of course. Inside the event horizon, all bets are off.

Certainly that is the standard view. If you include "magnetic charge" in "charge" I would completely agree.

I have a love affair with magnetic monopoles, so even thought there has been only one (not repeatable) observation of them, I think they were created as the standard theory suggests. (That observation was the current step in a supper conducting ring which was what one monopole passing thru the ring should have made.)

I am very attracted to the idea that back in the early universe when matter was "condensing out of energy" monopoles did form as predicted, but unlike the cooling and becoming neutral baryon / electron mix, they had power to strongly (not weak gravity force only) attract each other over long ranges for eons - "N pole seeking S pole for permanent union and black hole creation" was what a typical classified "sex ads" said back then. (Note that they individually are so heavy that a pair might form a black hole.)

Don't worry SpaceTiger I won't take this further as i did on our vacuum polarization / black hole exchanges. At least not here and if Chroot (Warren) has his way I will soon be banded form the forum - See my post in the subsection "Quantum Physics" thread about spectral line widths / line frequencys where as usual, you also made a good contribution to recently.

 

[Labguy]

From what I understand, the following quantities will COMPLETELY describe a black hole (theoretically):

- mass
- angular momentum
- charge

That is excluded to their observable properties, of course. Inside the event horizon, all bets are off.

Not exactly the original topic, but magnetic field was added to the list as a must several years ago. So the list is now:

- mass
- angular momentum
- charge
- magnetic field

But, I'm not in love with any requirement for "magnetic monopoles"...

 

[Chronos]

I have to agree, magnetic monopoles are a non-starter. Theories that predict them, predict them in great abundance and that is not supported by observations. I recall a simple, but haunting argument a physics prof once made: If magnetic monopoles were prolific, they would demagnetize everything.

 

[bayan]

Yes indeed I mean "matter" and what I mean by black hole is not around it or in the middle of it. I mean just inside the curvature of it. i.e Can a spaceship enter in a black hole?

 

[chroot]

Anything can enter a black hole -- the problem is that nothing can ever leave it once inside.

- Warren

 

[Billy T]

Anything can enter a black hole -- the problem is that nothing can ever leave it once inside. - Warren

Here we agree completely.
This is my I am not fully on board the the never observed, but very standard theory that "Hawkings Radiation" permits mass captured in the point singularity to "get out" with increasing rapidity and the hole "evaporates"

I.e. consider a black hole at time when its mass is just beginning to drop thru 100Kg and then very shortly later when its mass is 99kg. How did that 1kg "get out" from the point singularity?

 

[Labguy]

Here we agree completely.
This is my I am not fully on board the the never observed, but very standard theory that "Hawkings Radiation" permits mass captured in the point singularity to "get out" with increasing rapidity and the hole "evaporates"

I.e. consider a black hole at time when its mass is just beginning to drop thru 100Kg and then very shortly later when its mass is 99kg. How did that 1kg "get out" from the point singularity?

That has already been covered to the point of overkill. You have to do some serious reading, as this is now to the point of annoying...

 

[bayan]

So we do not need any space-time fabric to exist?

 

[hkhandrika]

I can`t think of any way that something with mass could travel through a black hole. Any object that enters a black hole will feel a huge gravitational pull and stay in the black hole.

Correct me if I`m wrong, but I think it would require an infinite amount of energy to move a massive object out of a black hole.

The mass would end up being ripped apart until it was mere atoms and travel towards singularity, but of course you can't just go to the center of the milky way (for instance), shine a flashlight, and hope to see where the matter that's being ripped apart from a nearby star ends up in a black hole


Agh i hit submit instead of preview (silly tired me ). I forgot to add that the only way we know black holes exist are through theory and by observations of their effect on other celestial objects in the universe. Since light cannot escape from a BH, you can't see it with the naked eye or through a telescope (optical). However if there is a star nearby, the star's hydrogen and helium and other elements it has synthesized through fusion will swirl towards the black holes center (like the water in your sink) and will get accelerated. The material will then release x and gamma rays (due to inverse compton scattering and bremstralung [I know I spelled this wrong... I can never spell this word]). This is something that you can observe and measure with x and gamma ray detectors. Therefore matter can enter a black hole and indeed travel through it. It will never return (as a previous poster mentioned), and you the observer will never see it finish it's travel after it entered (Stephen Hawking has a better description of why this happens... i don't remember sorry).

 

[misskitty]

Black holes have mass. If our Sun suddenly turned into a black hole, the Earth would continue to orbit the hole in exactly the same way it currently orbits the sun. The effect of the black hole's mass is the same as any other equal mass, more or less - so long as you're outside the event horizon.

Wait, I thought black holes absorbed everything that came in contact with them. Wouldn't that mean then we would not orbit the black hole, but instead be pulled into it due to its intense gravatational force?

 

[misskitty]

Too add a little, James mentioned the effect of a black hole is the same as any other equal mass. In general relativity, a key concept to understanding a black hole is spacetime fabric. Let's take a neutron star for example. A star with mass $x$ and density $y_{g/cm^3}$, explodes as a supernova, and forms a neutron star. Well this neutron star will still conserve it's mass $x$ (a little bit of mass is lost as the star's outer layers are blasted off, but it's not important now), but, it's density will now be around $y*10^{15}_ {g/cm^3}$. Atoms are so tightly packed that the protons and electrons merge into neutrons! So the denser a mass, the more spacetime is curved, the more spacetime is curved the stronger the gravitational force. A black hole is the same way. I used a neutron star because we know more of the numbers than we do a black hole. Right now all we say is a black hole is infinitly dense.
So, in my opinon, black holes should have mass.

Whoa, hold the phone here calhoon. Do you mean that when a star explodes and becomes a supernova, the protons and electrons of the atoms that made up the mass were brought so close together that they formed neutrons because their charges canceled out?!

 

[misskitty]

From what I understand, the following quantities will COMPLETELY describe a black hole (theoretically):

- mass
- angular momentum
- charge

That is excluded to their observable properties, of course. Inside the event horizon, all bets are off.

Why specifically angular momentum? Mass makes sense, charge makes sense, but I'm not sure about the angular momentum.

 

[misskitty]

Pardon my ignorance, but if a mass was able to travel through a black hole wouldn't that make the black hole a worm hole; which only exsist in theory.

 

[misskitty]

Please pardon my ignorance again , but monopoles have been mentioned in several previous posts. What are they?

 

[misskitty]

So we do not need any space-time fabric to exist?

Hmm, what do you mean? Interesting question, but where are you going with this?

 

[selfAdjoint]

Please pardon my ignorance again , but monopoles have been mentioned in several previous posts. What are they?

In Maxwell's equations for electromagnetism, it is stated that the divergence of the electric field is proportional to the local charge strength; this is true no matter how small a region you take to average the charge intensity over, so it predicts there will be point charges in electricity. But the corresponding equation for magnetism says its divergence vanishes identically everywhere, so in Maxwellian electromagnetism there are no point charges of magnetism, which is what the word monopole means.

But modern physics has modified the conclusion of Maxwell. Dirac proved that if there were even just one monopole, anywhere in the universe, then that would explain why electric charge is quantized, as it is; the quarks have charges of either 1/3 or 2/3 of an electrion's, either positive or negative, and we don't know of any smaller units. This fact has to be put in by hand in the standard model. But the standard model could in certain circumstances, which I don't yet understand, produce monopoles of its own. And cosmological monopoles could have other consequences.

So far, monolpoles, like tachyons, are ultra theoretical, but a fertile field for speculation, including by the biggest names in the business.

 

[hkhandrika]

Why specifically angular momentum? Mass makes sense, charge makes sense, but I'm not sure about the angular momentum.

Ok here is why you need angular momentum. The only way to detect a black hole is to observe it's effects on other objects in the universe. Let us say for example, a star comes far too close to a black hole. Due to the intense gravitational pull of the BH, the material of the star will literally be ripped apart and start swirling around the BH (THE MATTER DOES NOT GO STRAIGHT IN). This is due to conservation of angular momentum.

The analogy to this (and this is a VERY good analogy) is water in a sink. When you see water in your sink or toilet, you will notice that it swirls around the drain before it goes in. This is due to conservation of angular momentum. The same occurs in black holes. However after the matter that is traveling around the black hole increases in speed, and because of gravity, it gets pulled closer and closer until it finally loses all its rotational and orbiting motion and falls into the void. It goes to a singularity, but if you were to stand outside and watch it, you would never see it reach the singularity, because of how light is affected by a BH, it would seem to you the observer that it would take an infinite amt. of time for the matter to fall towards singularity. It would simply get closer and closer until it seemed to stop. However if you were to fall into a BH with let's say an "Anti Black-Hole stretchy-effect suit", you would see that piece of matter that you were watching intently go to singularity, and you would see some other effects of space and time if you looked out towards the universe you just were in. Good luck trying to get out of the BH though

 

[misskitty]

Thanks SelfAdjoint and Hkhandrika for being patient with me.

So what happens to the matter once it gets pulled into the black hole? Does it get broken down into its atomic particles?

 

[hkhandrika]

Thanks SelfAdjoint and Hkhandrika for being patient with me.

So what happens to the matter once it gets pulled into the black hole? Does it get broken down into its atomic particles?

The material will get torn apart until it becomes just atoms and subatomic particles. After that, no one really knows what happens other than it heads towards the singularity. Some have said that it leads into another universe... another dimension, only it's the BH that decides where you end up. It's like an elevator with no buttons.

But yes in a short answer the material gets ripped apart into atoms and sub-atoms, heated up and energized.