/sci/ - Science & Math

black hole is a point in space where theres even more vacuum than the vacuum of space, and pulls all the vacuum to itself

>>12527140
I dunno man...

black holes are schizo delusions by physishits, they dont exist

>>12527286
How do you explain the extreme orbits of stars around an incredibly massive but invisible object at the center of the galaxy as in pic rel?
I think we can generally agree its probably not an infinite density object that occupies no space. Speak your heart anon.... Are they universes, including ours and since the time and space coordinates switch at the event horizon, us moving towards the 'singularity' accounts for the experience we know as time?
Do you get smeared across the event horizon with the information of you fired out of the poles?
Are they a swartzchild diameter bundle of strings that preserves information by adding you to the string?
Is there an all consuming firewall directly behind the EH?
Come on bro its fun. Put on your imagination shoes

All timelike paths are inwards inside the event horizon so there can't be conventional outwards forces.
Black holes can have angular momentum and charge so the singularity has to be toroidal, all paths towards the toroid surface. Inside the torus you would have to move out to its surface, that geometry might stop it collapsing to zero volume.

>>12527458
>incredibly massive
Yes
>invisible
Extremely redshifted (it actually looks colder than the background radiation).
Going past the event horizon takes infinite time, so black holes cannot exist right now and are fun, but purely theoretical objects. Studying them is like studying FTL travel without asking yourself how do you get past the speed of light in the first place.

>>12527458
>smeared across the event horizon
>all consuming firewall directly behind the EH?
>>12528503
>Going past the event horizon takes infinite time
The event horizon isn't a real place and nothing special happens there. It's where an observer can't ever see events from beyond, but in different places in different reference frames. There's no firewall because you could go through where someone else says the wall would be like it's nothing.

>>12528518
The event horizon of a black hole is by definition a boundary that no light (or event) can escape, regardless of observer. It's not a black hole if someone could still somehow observe the insides while remaining outside. Therefore, no outside observer can ever see anything reaching this boundary, including the matter of the collapsing star itself, and it is still possible to interact with all of it like normal without having to go around any typical black hole paradoxes like singularities or information preservation.

>>12528674
>Therefore, no outside observer
Yeah but not all observers are outside observers looking at escaped photons. Jump in beside what you're watching fall, you'll be able to see it most of the way from horizon to singularity even if no one outside can. From your point of view the horizon stays below you (you can't cross it from your own pov) but it grows as you fall, restricting what you can see to a narrowing angle above you.

>>12527286
whats at the centre of the galaxy?

>>12528960
If you're outside the horizon, you're outside, no matter how close you are, and you still won't see anything ever reaching it.
One common argument is that the falling observer will reach the horizon in finite proper time. The thing is, the asymptotically infinite time dilation as the observer closes in on the horizon will make the trip far longer than it takes for the black hole to evaporate or otherwise cease to exist in one way or another, effectively preventing the observer and everything else from ever having enough proper time to reach the horizon.

WHAT is a black hole? Just a shit ton of mass, even more than a neutron star.

How does it look, behave, lifecycle, etc. I don't know, we can just do calculations and observations from afar.

>>12529378
Yes this confuses me. If you rode on a photon, to you it would be able to cross the universe instantly, while to a stationary observer it would take billions of years. Really though, how can anything reach the horizon without experiencing the evaporation of the BH in a similar instant? (I assume point at which escape velocity exceeds c is also the point at which time dialation becomes infinite.

>>12526954
>pokes hole in paper

>>12529050
A smaller galaxy.

>>12529540
Here's another fun thing to consider: masses interact through gravitation, but if the mass goes behind the horizon no such interaction should be possible anymore because it will either imply FTL transmission of information or violate the laws of conservation. In other words, the mass that fell into black hole should essentially disappear.

>>12530239
The mass could perhaps exist at the very perfect edge of tue EV as a sort of ultra degenterate shell. Or maybe something like the fuzzball theory is correct.

>>12530270
Or maybe it is indeed simply gets stuck there almost frozen in time dilation never quite reaching the horizon

>>12529378
>asymptotically infinite time dilation as the observer closes in on the horizon
>preventing the observer and everything else from ever having enough proper time to reach the horizon
>>12529540
>point at which escape velocity exceeds c is also the point at which time dialation becomes infinite
That dilation's only from the perspective of a distant non falling observer. Events in the falling frame like passing the horizon (meaning escape velocity c to the distant observer) and reaching the singularity still happen in finite proper time.
>>12530239
Isn't this solved by gravity being a spacetime geometry effect? The interaction is by distortion of spacetime which can be >c, not by <=c transmission of information through spacetime.

>>12530924
Time dilation works both ways, i.e. the falling observer will have its proper time appear to flow like normal, but see distant universe blueshift and likewise asymptotically accelerate to infinity instead, and the order of events will still be the same.

>interaction is by distortion of spacetime which can be >c
Interaction is not just attraction, it affects the movement of masses and in turn the way they distort space-time through emission of gravitational waves. Those travel at the speed of light and cannot escape the event horizon, so interaction across it will be asymmetric and violate laws of conservation and therefore is not possible.

>>12530924
I understand that to the observer time doesnt feel like its going slow. It doesnt feel slow if you were a sentient photon either. But what a photon WOULD experence is that relative to most of the rest of the universe its clock its running much slower. Hence the crossing the universe in an instant from its perspective. Same reason the twin that stays behind is older.

>>12526954
relativity has already shot all the junk that fell into a black hole back out at the end of time. It will have been subject to spaghettification so a physical object that went in won't come out the other side, but the atoms and particles could.

You see, because of hawking radiation a black hole is always shrinking. Virtual particles are dragged apart at the event horizon, giving them physicality and allowing mass to escape from the black hole. This means that a black hole is always losing mass at a rate proportional to it's surface are times some constant. thanks to the square-cubed law, this means that smaller black holes lose percentages of theior overall mass much faster. Eventually every black hole will collapse into a white hole, spewing all it's mass back out into the cosmos at the end of time.

On the other side we have the Cosmic Microwave Background. This energy permeates all of reality, and is constantly falling into black holes being absorbed. Because of how small the mass loss of a black hole via hawking radiation is, absorbing the cosmic microwave background actually stabilizes black holes, making ones larger than about the mass of the moon grow rather than shrink. As the universe expands in the future, the cosmic microwave background will dim further and further, raising the mass needed for a black hole to be growing from it alone. This means that eventually, unless the expansion of the universe stops, all black holes will eventually collapse, fizzling out into nothingness.

(1/2?)

>>12531241
So, we have objects falling in being accelerated closer and closer to the speed of light, being slowed down temporally from an external perspective, but still technically there.... But that's what the original black hole is in the first place, right? The core of a star collapsing in on itself, accelerating at relativistic speeds being further and further flung into the future by it's own momentum and unable to actually reach a singularity... so it's actually most likely that all the mass of a black hole isn't in the middle, but is quite densely concentrated at the surface. This explains why quantum fluctuations at the edge of the black hole can release matter: The virtual particle that is created inside the black hole annihilates in the dense outer shell of extremely closely packed, relativistically frozen matter, while the other particle escapes just barely.

all in all, A black hole is a frozen implosion being annihilated particle by particle by the quantum fluctuations of reality itself. The matter that falls in doesn't get compressed into a singularity because it doesn't have time to, it simply forms a shell of ridiculously high density, getting slowed down more and more, it's position relative to the event horizon basically fixed.

It seems that in thinking about it for longer, my initial statement came undone. Relativity doesn't shoot all the junk out at the end of time, it forces reality to annihilate virtual particles on the edge of the event horizon so the black hole never collapses into a singularity at all.

>>12531256
OP here. Thats a good post anon. Its strange that more people dont arrive to a similar conclusion given what we know about time dialation.

>>12531116
I thought i read somewhere that any infalling matter would be fried by the super blueshifted light. Makes a kind of sense i guess.

>>12531256
>all in all, A black hole is a frozen implosion being annihilated particle by particle by the quantum fluctuations of reality itself. The matter that falls in doesn't get compressed into a singularity because it doesn't have time to, it simply forms a shell of ridiculously high density, getting slowed down more and more, it's position relative to the event horizon basically fixed.

This seems to me to be the best evaluation ive heard thus far with what we know. Seems far more plausible than a singularity.

>>12532599
Wait wouldnt everthing at or behind the event horion also be similarly dilated? So would it behave and experence time at the same rate as the astronaut at the event horizon. So what would this look like to fall in? An approach followed by an instantaneous squeeze-bang?

>>12531147
It crosses the universe instantly because the universe is going at c relative to the photon and has its length contracted to zero. It takes no time not because the photon's own clock is slower but because there's no distance to cover.
>>12531116
>Time dilation works both ways
Yes but
>likewise asymptotically accelerate to infinity
I don't think that's right. It's not symmetric, the distant observer can see the faller frozen at the horizon forever, but the faller isn't frozen at the horizon able to collect photons from throughout the distant observer's infinite future. The faller can only see what's in his own past light cone, he only sees photons when/if they catch him before he hits the singularity.

>>12526954

Big object collapses. Big object is now smaller but has same mass. Smaller object with same mass has more density. Now more dense smaller object has more gravity.

>>12533916
Actually asking, but how could it not be right? We know that a clock in a gravitational field runs slower than one farther away. This effect is more pronounced the stronger the gravity. Is there like, a ceiling that is caps out at? Because i would imagine (for some reason idk) that at the point where escape velocity exceeds c, the clock present slows to 0.
You wouldnt feel like you were slowing down, you would experence things normally until you were at the cusp of crossing and then the black hole would evaporate. The unverse behind you would ultra blueshift and eons would pass in a moment to your eye looking back out at infalling photons.
To those watching you you would freeze at the edge then redshift away.

I think.

>>12533987
Whoa look out for this guy!

>>12534012

It's unironically how it works, and how someone had the theory in the first place, then the math came from that and you have your "not even light can escape this!" black hole theory born. Everything else is just filler outside of direct observations.

It checks out, and we can apply the same theory to anything.

>>12526954
Don't post it...

>>12533987

Everything is this simple in the end.

>>12526954
How big would a black hole have to be so it wouldn't rip you apart as you entered it? Are there any known klabc eloh's with tidal forces that wouldn't rip you to schreds?

>>12533916
>distant observer can see the faller frozen at the horizon forever
Not exactly frozen, just extremely redshifted and slowed down, enough for the however billions of degrees the matter is heated up to there to look like nanokelvins to us on the outside, and a single second of time inside last multiplie ages of the universe.
On that note, the cosmic background radiation of 2.7K is blueshifted down there to look even hotter, quite a few orders of magnitude hotter in fact. It kinda goes to a whole new level of ridiculous, if you think about it.

>>12526954
Black hoe is your black girl, when you are in trash rap.

>>12526954
It still has color you dumb bitch.

>>12532599
>>12533332
Once you cross the horizon, you'll see the universe behind you die out. A black hole is a one way passage to the end of time and the universe.

>>12526954
Calling it black HOLE was the one of the biggest mistakes of science. A lot of people don't realize that it's just a star with a very big gravity.

>>12536402
Its strange that this effect is so fantastical but not spoken of more often. We dont know a lot about black holes but it seems that we can infer that if they do indeed posses an EH then there is indeed ultra redshifted, ultra slowed material concentrated at the very edge of the BH.

>>12536402
If we ever get within flying distance, black hole suicide will become a thing

Im pretty sure I know whats beyond an EH
>10 years of studying
its so obvious, so I just constantly get lulz why people still cant see that, bc everything literally comes from GR, you just need to watch it from completely other angle and perspective

I dont see a problem with the softhair theory

>>12538709
Enlighten us, retard

>>12538811
That was a good read, thanks mate.

>>12536458
In the 18th century, John Michell first suggested the idea of stars so massive that light couldn't escape them. He coined the term "dark stars" to describe the hypothesized body. Frankly I think that's a much better, much more accurate term.