/sci/ - Science & Math

[Anonymous No.5673606]

Don't blackholes contradict the the law that "the total energy of the universe is constant"?

[Anonymous No.5673614]

...No? Why would they?

[Anonymous No.5673622]

>>5673614
I mean, where does all of that matter go?

[Anonymous No.5673630]

>>5673622

Black 'holes' are not holes. They are not tunnels to another dimension. They are super concentrated matter. The mass of the giant star, squeezed into a much smaller volume. The matter joins with the other matter, and the total mass of the black hole increases. Nothing is destroyed except information.

[Anonymous No.5673633]

>>5673622

Not the person you were responding to but, I'd say picture the black hole as a neutron-star-like sphere (like in your picture) rather than a wormhole. It doesn't go anywhere outside of the universe really, just into the infinitely dense area of the black hole.

I'm sorry if I've fucked up in this explanation, please don't beat me.

[Anonymous No.5673654]

>>5673622
Collapses into a singularity. Imagine squeezing the Sun's mass into a grain of sand. Contrary to what pop culture will tell you, they're not a bunch of malevolent cosmic vacuum cleaners. And they actually do spit out stuff occasionally. See Hawking radiation.

[Anonymous No.5673657]

>>5673622
white holes in another multiverse

[metric !1tensorX8Q No.5673667]

Short answer: no, the energy of infalling matter is simply trapped at the singularity.

Longer answer: It wouldn't matter, since global energy conservation isn't required in GR. You only get energy conservation when there's time-translation symmetry. Our universe is not t-translation symmetric, so the energy of the universe is not constant.

[Anonymous No.5673726]

>>5673633

>I'm sorry if...

Nope, actually you're spot on.

>>5673654

>a singularity

That's open to conjecture. If you have your sun-sized grain of sand, it may have a field of gravity that contains an event horizon but the grain of sand still isn't a singularity. How are you going to tell anything about the distance between the center of the event horizon and its surface if photons (or any other particle for that matter) can't return after crossing it? Just because an equation implies a trend towards infinity doesn't mean it actually happens.

Further, hawking radiation doesn't mean that black holes emit anything from the center. The fluctuations that produce real particles occur on the event horizon. The loss of conservation of information is still a theoretical problem in physics; the particles that go into a black hole might not be the same ones that cause evaporation through radiation. I think Leonard Susskind talks about this and the holographic principle or somewhat in a pbs show.

A black holes usually cause matter that doesn't cross the event horizon to accelerate a whole lot which in turn causes a whole lot of thermal agitation. Surrounding gas is either ejected from the area or enters into orbit around the event horizon essentially preventing decaying orbits from forming. The theory is that a black hole's mass may increase shortly after it's formation but eventually stabilize because it's nearby area is empty space.

[metric !1tensorX8Q No.5673744]

>>5673726
>Just because an equation implies a trend towards infinity doesn't mean it actually happens.
Everyone knows quantum gravity is required to deal with the singularity, and that GR will almost definitely break down. Still, I find that sentence very naive. GR has been confirmed to high accuracy. It's not just "because an equation said so," it's because a time-tested theory said so, for which we currently have no better replacement.

[Anonymous No.5673761]

This might be ignorant but I'll say it anyway. Is the universe a hologram?

[Anonymous No.5673780]

>>5673630
>nothing is destroyed except information
>Hawking radiation
Back to school.

[Anonymous No.5673816]

>>5673744

Evidently not everyone since I was under the impression that string theory is the best candidate for quantum gravity because it specifically DOESN'T deal with singularities. What we assume to be point-like in quantum mechanics have components in dimensions other than regular spacetime. I donno that could be wrong...

>has been confirmed to high accuracy
>naive

On the contrary, I think it's naive to assume that there is no bias in where choose to test a law in that it's absolutely representative of the entire universe. Kepler's law of planetary motion was also pretty experimentally accurate until we found that Mercury's orbit is actually precessing. Orbits look a whole lot like ellipses but if you take the right measurements you find rosettas. Our fundamental understanding of the phenomenon of orbits happens to be exactly what the equation tells us and the right equation gives us the right understanding. In reality, they're all wrong because a phenomenon doesn't adhere to an equation, it just is; even for time-tested theories.

It's ok to admit that knowledge has limits and we can't know anything beyond it.

[Anonymous No.5673844]

>>5673633
so if you're correct where is all that absorbed matter being stored?

[sage No.5673857]

did you know that you can BEND space with blackholes?
inb4 this

[Anonymous No.5673862]

>>5673857
Anything with mass bends space.

[Anonymous No.5673864]

>>5673857
Yeah, that's what gravity is.

[Anonymous No.5673871]

I love watching you people make assertions that have no factual proof. Its like watching women argue.

>black holes are not holes
so you have actual observed evidence for this? have you even seen one?

>hawking radiation
lol

Also stop confusing theories with hypothesis.

Is it really this hard to admit that you don't know?

[Anonymous No.5673906]

>>5673761

No, but our perception of it probably is.

>>5673780

NO U. Hawking radiation implies information is lost specifically because the emitted particle and the mass of the black hole are on different sides of an event horizon; they cannot be causally linked. The particle's information comes from a reference frame on the surface of the event horizon. What propagates the information from the singularity to the event horizon when the black hole loses the particles mass? Information is either destroyed or exists 'stretched out' on the surface of the event horizon ie the holographic principle.

Also, I should add that hawking radiation is a theoretical prediction, it's never been observed. It might not even happen.

>>5673844

It's still in spacetime, it's just spacetime is so super-warped that light doesn't show its there by reflecting off of it.

[Anonymous No.5673907]

>>5673622
This is pretty new, but all the information (including material objects) get smeared around the outside of the event horizon.

[Anonymous No.5673911]

>>5673871
>I love watching you people make assertions that have no factual proof. Its like watching women argue.
>>black holes are not holes
>so you have actual observed evidence for this? have you even seen one?
It's very easy to discuss black holes, they are theoretical entities.

[Anonymous No.5673913]

>>5673906
Since we're on the topic of black holes, I watched a video recently about some guy explaining that once you cross over the event horizon, but you are not absorbed by the singularity yet, there lies a brief period of time where you are moving towards the singularity, but you can't ever go back, not because of the gravity pull or anything, but because all trajectories that lead back now lie in the past.

Can you explain this, I don't seem to get it. How come "there is no direction" which could lead you away from this singularity?

[Anonymous No.5673918]

>>5673871

>actual observed evidence

No, but the theoretical evidence that predicts the existence of black holes defines them pretty clearly as not holes. In fact, it'd be pretty difficult to have observable evidence about something that can't be directly observed.

0/10
Trolling from ignorance is actually just ignorance.

[metric !1tensorX8Q No.5673933]

>>5673816
>I was under the impression that string theory is the best candidate for quantum gravity because it specifically DOESN'T deal with singularities.

I'm not familiar enough to comment on string theory. By "deal with the singularity" what I meant was "make it go away." I guess I should have been more clear.


>On the contrary, I think it's naive to assume that there is no bias in where choose to test a law in that it's absolutely representative of the entire universe.

I'm not sure what you mean by "bias." Physics is about creating models that are supposed to correspond to observation. We use and exploit those models until they have shown to conflict with observation. You push the model until it no longer works, and then you come up with a new/better one.


>It's ok to admit that knowledge has limits and we can't know anything beyond it.

When did I ever imply the contrary?

[Anonymous No.5673944]

>>5673918
>theoretical evidence
so I guess... all theories can produce evidence thereof... like the bible...phlogiston... Buddhists...(insert theory)

>cant be directly observed
yup sounds like a familiar statement made by an ignorant person. (go back in history and count how many times people said that "X" is not possible)

in time, perhaps you will accrue a higher wisdom than the embarrassing quantity you possess at the moment, kid.

[Anonymous No.5673965]

>>5673944

hurr durr, you can't see blackhole so there's no evidence for them

we can infer their existence by the behavior of objects nearby that obey exactly how they should behave if they were around black holes

[metric !1tensorX8Q No.5673973]

>>5673913
There are multiple ways of addressing this question. The easiest way to show this is true is to recognize that the Schwarzschild t-coordinate becomes spacelike inside the horizon, while the r-coordinate becomes timelike. Just as you can't avoid getting older, you can't avoid falling into the singularity.

But that might be more technical than what you're looking for. Another way to explain it is by sketching the light-cone's dependence on the r-coordinate (pic related). The "cone" illustrates which paths are possible without traveling faster than light-speed. Once you pass the event horizon at r=2M, all of the cones point inwards toward r=0.

If that's still too technical, the most intuitive way to think about a black hole is like a stream with a waterfall. The water moves faster and faster as you approach the edge. Eventually there is some invisible point where the speed of the water is faster than the speed you can swim, and you're doomed to fall off the edge. Similarly, you can think of the black hole as a "waterfall" with space "falling" into it. Eventually you'll reach a point where space is falling in faster than the speed of light, so no matter what you can't get out. This is called the "river model." See, e.g. http://arxiv.org/abs/gr-qc/0411060

[Anonymous No.5673983]

>>5673944
>in time, perhaps you will accrue a higher wisdom than the embarrassing quantity you possess at the moment, kid.
not the same guy here, but...
lol, why are you trying to act tough on an anonymous board? is this the only way you are able to feel like a man since you haven't accomplished anything of worth in your wretched life?

[Anonymous No.5674000]

>>5673944
Are you trying to act all smart because you got an A+ in remedial sciences in High School or something?

[Anonymous No.5674001]

>>5673913

So, spacetime is a 4 dimentional manifold, the three spacial dimensions and a time dimension. Gravity affects those dimensions in all the same way; it not only curves space but also dilates time. Because the affect of the black hole is so drastic, it leads to pretty weird consequences...but then again, lol, paradoxes.

As you're falling towards the black hole, an observer in an outside reference frame (the people who threw you in from a safe distance, for example) measure the time you should be experiencing at a slower and slower rate. This happens for the same reason that if you're traveling near the speed of light, time seems to speed up in comparison to everywhere else. A year to you is really longer for everyone else; time dilates due to acceleration. The event horizon of the black hole is the point at which these effects prevent light from escaping because the acceleration needed for a trajectory away from the black hole is exactly c.

So, when you pass the event horizon, outsiders see you as not moving through time at all; it's literally stopped. But for you, you're still falling because you're in the reference frame that's being accelerated. If you happen to get out from beyond the event horizon (Doctor Who telephone booth style), you appear at a point in your past because observers are still observing you stopped in time on the event horizon; you've never crossed it for them, and thus also for you. You'd also be able to see your past self on the event horizon as well...so really, who are you?

TL;DR fuck temporal paradoxes. They're not suppose to make sense.

[Anonymous No.5674003]

>>5673965
now marvel as your intelligence spews all over the place leaving only an arrogant little kid defending his standpoint like a good martyr regardless therof how close your limit converges to insanity.

"and I can infer that a god exists because be bopity zoo reality doesn't make sense so... bazinga! god makes sense!"

welcome to the next paradigm.

>>5673983
I'm guessing you deduced the notion of me 'trying to act tough' from my ending word "kid".

Let me assure you,
I am not trying to act tough.

[Anonymous No.5674009]

>>5674003
>good martyr regardless therof how close your limit converges to insanity.

[Anonymous No.5674014]

>>5674003
This is why you should never wield a thesaurus without proper training

[Anonymous No.5674019]

>>5674003
Do you even science?

[Anonymous No.5674020]

>>5674003
>"and I can infer that a god exists because be bopity zoo reality doesn't make sense so... bazinga! god makes sense!"

Except the evidence suggesting the existence of black holes is more convincing than "be bopity zoo reality doesn't make sense so... bazinga!"


Nice try, kid

[Anonymous No.5674024]

>>5674014
>>5674009

oh i'm sorry, I figured that /sci/ would have a developed vocabulary.

[Anonymous No.5674031]

>>5674024
And I figured /sci/ would, I don't know, understand things like how science is done.

[Anonymous No.5674038]

>>5674020
>more convincing

lol try to be frank here, gentlemen. what sounds more "convincing" or whatever that means....

case 1: spooky action at a distance, and.. etc..

case 2: intelligent design.

the default answer is obvious, only arrogant fools and the sickly minded would answer the contrary.

now, as for >>5674019
are even of age to be on this board? that's like a statement from a bill nye video.

[Anonymous No.5674042]

>>5674038
I bet you don't believe in evolution either.

[Anonymous No.5674046]

>>5674038
Oh look, a false reduction to two choices.
I'd still take Case 1.

[Anonymous No.5674048]

>>5674038
>http://rationalwiki.org/wiki/Poe's_Law

So either keep trolling or stay stupid and enjoy a High School level of knowledge, doesn't matter to me.

[Anonymous No.5674049]

>>5673871
This..
How do you guys even know this much about a Black hole if you've never experimented with one

[Anonymous No.5674051]

>>5674049
Except that we essentially have.

[Anonymous No.5674056]

>>5674048
>>5674046
>>5674042

and now you have retreated into a dark retort of arrogance and ignorance. a chilling combination.

my work here is done

[Anonymous No.5674060]

>>5674056
Evidence gathered from empirical observation is a "dark retort of arrogance and ignorance". Ummmmmmmm, k.

[Anonymous No.5674073]

>>5674056
>and now I am euphoric

Congratulations, you out-trolled people on the Internet. You can tell your children about it some day

[Anonymous No.5674079]

>>5673983

I'm the same guy here, and I approve this post.

>>5673933

Firstly, yeah, my understanding of string theory comes from Brian Green so I'm no expert either.

Secondly, about physical law. Laws are true everywhere in the universe. It's true everywhere that gravitational forces are proportional to the masses of the two objects and inversely proportional to their distance (squared...whatever). However, you have to make the assumption that making the measurements in a lab is the same as making the measurements near a black hole. General relativity pretty dramatically shows that distance and time aren't linear in gravity fields so really the bias comes from such assumptions.

Since we can never know if our laws function the same inside an event horizon (can't take the measurement to see if it works) assuming a model to be correct is bad reasoning. I think you have to choose to ignore this to imply any predictive power about the insides of a black hole.

Tbh, I'm being pretty opinionated anyway so I'm pretty sure I don't even know what I'm saying.