BlackHoles

[MokieMan]

Well ive done some research and have studied this topic a little bit, but ive always wondered what happens when matter gets sucked into a black hole. People always say that its gone and it doesn't exist anymore. There has also been some speculation that black holes are like wormholes and can transport you to alternate dimensions or other universes. i support this theory only because matter cant be created or destroyed but only transformed, its a real law look it up. so i want to know your opinions and see if there is anything else possible. Thanks!

[Brethern]

Laws change every day, nothing is set in stone.

[TheDarkStar]

Laws change every day, nothing is set in stone.

The laws of the universe tend to be somewhat unchanging.

In response to the OP: The matter doesn't go anywhere. It essentially becomes part of the black hole, increasing the black hole's mass.

[nipulsansei]

To expand on TheDarkStar's answer:

A black hole isn't an actual hole in the universe, it's a massive object in space that draws in any matter or energy that crosses it's event horizon; such that even light is condensed into and made part of the black holes singularity, thereby causing the singularity to be that much more massive.

So, the laws of conservation of mass and energy are not broken. The mass and energy are still there, just condensed into singularity of a black hole.

[Brethern]

The laws of the universe tend to be somewhat unchanging.

In response to the OP: The matter doesn't go anywhere. It essentially becomes part of the black hole, increasing the black hole's mass.

It was what? 400 or 500 years ago that people believed everything orbited around the earth, our knowledge of the universe is barely a drop compared to what's out there.

So you'll excuse me for waiting till I make a statement like that.

[YNM]

It was what? 400 or 500 years ago that people believed everything orbited around the earth, our knowledge of the universe is barely a drop compared to what's out there.

So you'll excuse me for waiting till I make a statement like that.

The actual "nature's rules" never changes. We just continually change our viewpoint over it. Geocentrism calculations are fairly accurate, but it's very complex. Heliocentrism makes it easier while achieving a better precision. Then there's the current cosmological principle.

Much the same to gravity (forces to curvatures), electromagnetism (forces to particles), then we discover new things like strong and weak forces. The rule itself never changes, we just discover more of it. Newtonian gravitational forces can be very precise if you introduce corrections into it, but then GR is simpler (more generic and requiring less corrections), and far more precise.

--------

On Topic :

It simply becomes one with the black hole's mass. No way to distinguish it.

[AngelLestat]

The answer is easy, nobody knows for sure yet.

We do not have tools (math, strong theories or experiments) to know exactly what happens inside a black hole.

[Dedjal]

Time and space can be viewed as a fabric woven together.

If you punch a hole in it, it would unravel.

So since I am still here, a " black hole" can not be a gateway to another universe.

My opinion at least.

Only way to figure out if time and space works that way would be to punch a hole in it and see what happens.

[Nibb31]

A black hole is not a hole. It's a very very very heavy object. So heavy that its own gravitation pull has caused it to collapse on itself, making it very very very dense. It's so heavy that it attracts all the matter nearby to crash into it, making it even heavier and its gravitational pull even stronger. It's so strong that even photons can't escape, which is why we can't see it.

[Hcube]

Very interesting, especially the second part about density. Black holes aren't necessarily super dense since their radius grows linearly with their mass, but they are spheres so their volumes grows by the ^3 ... So as you get heavier, you become larger, thus less dense (not very right-ish math-wise the way i wrote it but you get the point)

[KSK]

The Wikipedia article looks interesting as well.

Personal aside - and without wishing to pick on Brethern in particular, please can we mentally add 'so far as we currently know' to any comments on this thread? Black holes are plenty weird enough for us to have an interesting discussion about them that doesn't devolve into:

"Science says this."

"But science doesn't know everything, therefore I ignore your arguments."

Which doesn't really get us anything other than heated tempers and a locked thread. Speaking personally, as far as I'm aware, AngelLestat is right - we don't (and won't) know exactly what happens inside a black hole and until - and maybe not even then - we have a working theory of quantum gravity. I might well be wrong.

[AngelLestat]

A black hole is not a hole. It's a very very very heavy object. So heavy that its own gravitation pull has caused it to collapse on itself, making it very very very dense. It's so heavy that it attracts all the matter nearby to crash into it, making it even heavier and its gravitational pull even stronger. It's so strong that even photons can't escape, which is why we can't see it.

The "heavy" word does not have much meaning from the black hole perspective, if you dont know for sure if the BH inside is included in this universe or how the BH inside structure looks like.

Is heavy from our point of view.. But for us is just a mistery object with a horizon radius, we can just speculate (or education guest) on its properties beyond that horizon.

Edited June 17, 2015 by AngelLestat

[rtxoff]

The first thing humankind probably should do is to confirm that black holes even exist. AFAIK no one has directly observed one so in reality they might not exist or even be of a different nature then we think.

[ZetaX]

AFAIK no one has directly observed one so in reality

That's because that is literally impossible. Or you have a weird definition of "directly observed". Nothing escapes from them, so no seeing, no touching, no going in there and telling us. We have several indirect indications from gravity influencing stars, accretion disks and lensing. And we have formal reasons to consider them real from relativity.

There might be errors (e.g. maybe "certain information can escape if [weird conditions]" or "those smaller than 1m instantly vanish by the yet unknown fifth fundamental force"), but one akin to "black holes simply don't exist" is very unlikely.

[NFUN]

Very interesting, especially the second part about density. Black holes aren't necessarily super dense since their radius grows linearly with their mass, but they are spheres so their volumes grows by the ^3 ... So as you get heavier, you become larger, thus less dense (not very right-ish math-wise the way i wrote it but you get the point)

Thing is, those calculations work when considering the volume of the black hole to be the Schwarzschild Radius, but the actual singularity itself is still a singularity, and remains brokenly dense.

[rtxoff]

*snip*, but one akin to "black holes simply don't exist" is very unlikely.

And that last statement is based on what? Science? Observation? Mathematics? Trolling?

For me it seems it's based on hype. One guy got the idea there might be black holes and everyone liked that idea and build a framework around that. Today nobody doubts anymore about their existance even without ever seeing them or having rock solid evidence for it.

It's easy to claim something is there if that thing is not observable, detectable or whatever. It's as good as claiming there is a omnipotent being but it won't step in contact with us.

[TheDarkStar]

And that last statement is based on what? Science? Observation? Mathematics? Trolling?

For me it seems it's based on hype. One guy got the idea there might be black holes and everyone liked that idea and build a framework around that. Today nobody doubts anymore about their existance even without ever seeing them or having rock solid evidence for it.

It's easy to claim something is there if that thing is not observable, detectable or whatever. It's as good as claiming there is a omnipotent being but it won't step in contact with us.

But black holes are detectable. They don't emit light directly, but they have a massive gravitational pull. Observing the velocities of stars near black holes gives us an estimate of their mass; some of the masses are billions of times the mass of the Sun. Their mass also tears apart things that get too close, causing those things to emit a large amount of energy. There's also a theoretical reason and (admittedly incomplete) description of them.

Edited June 17, 2015 by TheDarkStar

[KSK]

And that last statement is based on what? Science? Observation? Mathematics? Trolling?

An 18th century thought experiment which was put on a solid theoretical footing through General Relavity and later shown to be a generic result of General Relativity that doesn't depend on any assumed conditions. Black holes are also a logically consistent extension of processes resulting in other astronomical bodies which are observable - from Wikipedia:

"In 1931, Subrahmanyan Chandrasekhar calculated, using special relativity, that a non-rotating body of electron-degenerate matter above a certain limiting mass (now called the Chandrasekhar limit at 1.4 M☉) has no stable solutions.[15] His arguments were opposed by many of his contemporaries like Eddington and Lev Landau, who argued that some yet unknown mechanism would stop the collapse.[16] They were partly correct: a white dwarf slightly more massive than the Chandrasekhar limit will collapse into a neutron star,[17] which is itself stable because of the Pauli exclusion principle. But in 1939, Robert Oppenheimer and others predicted that neutron stars above approximately 3 M☉ (the Tolman–Oppenheimer–Volkoff limit) would collapse into black holes for the reasons presented by Chandrasekhar, and concluded that no law of physics was likely to intervene and stop at least some stars from collapsing to black holes.[18]"

Finally, they also account for other observed phenomena as mentioned by ZetaX.

So, maths, observation and science but not trolling. Black holes might not be real but any alternative explanation for observed phenomena such as, for example, gravitational lensing, will also need to explain and be consistent with a lot of other observations and theory.

Edited June 17, 2015 by KSK

[justidutch]

This is reminding me of Dark Matter. Until just a few months ago, DM was just a theory to help explain stuff that we predict should be there but couldn't see or measure. But now we can, and DM is so far showing up where the theories suggested it would. Or close enough.

One day, someone will brainiac a way to define and measure just exactly what a black hole is. Hopefully that person also discovers that they (the black holes) are non-sentient.

[YNM]

The answer is easy, nobody knows for sure yet.

We do not have tools (math, strong theories or experiments) to know exactly what happens inside a black hole.

The metrics exists though. Of course, none tested thoroughly yet.

Time and space can be viewed as a fabric woven together.

If you punch a hole in it, it would unravel.

So since I am still here, a " black hole" can not be a gateway to another universe.

My opinion at least.

Only way to figure out if time and space works that way would be to punch a hole in it and see what happens.

What "hole" ? Is there a hole in 4 dimension ? What, 5 dimensional hole ?

Black hole isn't a hole, at all. It just don't letting any photon arrives at your eye from it, creating the appearence of a dark, "black" hole.

For it's evidence, as the name implies, you can't directly observe it with your eye, nor you can get some rulers and measure it's radius, or get some weighing scales and weigh them down ; they're observed indirectly through their intense gravitational effect (name a few, G2 star cloud for milky way's), superluminal jets, and stellar motion (like, the S stars in milky way). Their "radius" (as blackholes matter are concentrated in the central singularity, with infinite density. BH's radius are their schwarschild radius) are confined by the minimum distance (periapse) of things that orbits them, which brings to a really dense object none can serve unless a black hole.

[jfull]

It always bugs me when the OP asks this sort of thing and then doesn't reply afterward...

[78stonewobble]

Well, I for one, refuse to believe in singularities. *lol* Which is to say, I don't have a problem believing in black holes or densities large enough to cause an object to have a schwarzschild radius, but I do have a problem with infinite density. That I don't believe in... I think some unknown process must hold the collapse, before this happens.

I also reserve a grain of salt for dark matter. It's probably there, but til we have a better explanation of what it is and how it works, I think it would be prudent to assume we might not know as much as we think we do. Personally I think, that if gravity, dark matter and dark energy were all variations of the same thing, it would be a far more elegant solution, but offcourse the universe listens very little to me.

[beabop]

As I understand it, we don't know what a black hole is like because we have no idea how relativity (and thus gravity) works at a quantum scale. So if we unify quantum physics and relativity (the Theory of Everything), then we could figure it out.

[AngelLestat]

The metrics exists though. Of course, none tested thoroughly yet.

That is not the end of the story... we are not talking about just GR or Quamtum gravity ignoring some laws of quamtum theory..

The only thing we know is that we have a lot of different theories making very different predictions compared to their counterparts.

For one side you have the firewall paradox which it said that if you fall into a black hole you will literally hit this horizon wall. Then we have theories which talks about new universes inside the black hole "insert here big bang, white holes and wormholes", then we have theories that prohibits the black hole formation for interstellar masses due hawking radiation. Then we have string theory with its multiple dimensions and some math tools as the holographic universe.

All these theories, from the math point of view.. are all correct (for now), so what is wrong then? the conclusions? the math? the hypothesis?

So the only conclusion is that there is something wrong with our know physsics in the black hole frame. We need a new physsics or someone needs to provide extra evidence to point that his/her theory is the correct.

Edited June 18, 2015 by AngelLestat

[SciMan]

AngelLestat, that's pretty much exactly my opinion on the subject.

Basically, if you can't tell the difference between two (or more) theories, they are either the same theory in different terms, or you don't have enough data yet.

And for the theories that are being considered here, acquiring data that is good enough to constitute proof of one of those theories (or a new one we haven't considered yet) will take equipment that is absolutely massive compared to anything humans have ever constructed.

Particle accelerators that make LHC look like a pea-shooter, for example.

I'm talking stuff that would make even the Great Wall of China look like a desk toy. Stuff this size is by design a multi-national project, simply because it's so big that it MUST cross national borders.

Basically, I think I have an absolutely miniscule chance of ever seeing any attempt at a physical proof of these theories, because the sad fact is, if it takes more than 4-10 years from initial investment to first results, it might as well be impossible.