Black Holes
Black Holes
125 comments
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My understanding is that the singularity is not proven to exist and many physicists believe it is an artifact of our incorrect understanding of the physics involved.
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Well, what exactly is inside the event horizon is unproven because we cannot possibly look. All of the rest of the physics seems to check out, though, and we know that there are things out there that behave just like our models of black holes predict. It's an incomplete understanding rather than a necessarily incorrect one. If it is something else, it'd have to be something that looks more or less exactly like a black hole to an outside observer
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I would think an object of extremely high density could be difficult to distinguish from a point of infinite density, especially given the nature of the event horizon.
I’m not saying the models are definitely wrong but usually when one of your terms goes to infinity it is a good reason to be skeptical.
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All of the rest of the physics seems to check out, though
What is the entire problem, because all of the rest of the physics don't get you coherent answers around a black hole.
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All of the rest of the physics seems to check out, though
You know, except for the actual singularity which has no interpretable meaning in physics
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All of the rest of the physics seems to check out
If the whole universe comes from the singularity and you need just a tiny fraction of it in a limited space to create a black hole, why the universe even exists and even more so, it's expanding each day faster?
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"marauding black death wrapped in a spherical gradient of tortured space time" is a great title for a progressive rock or technical death metal song
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"In a spherical gradient of tortured space time" is a great title for an ambient or very slow.and moody electronic music album.
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Tell me you don't understand black holes using a lot of words.
As far as gravity goes they are equivalent to the star that they collapsed from and just as deadly.
The difference is that you can get that much closer before "impacting" with it, but you and superman would be fucked pretty much at the same distance from it.
And I think you need a lot less than 300 writers to conjure an idea that leverage our fantasy in more and better ways.
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And an infinitely dense point in spacetime doesn't necessarily exist: it's just what general relativity predicts is at the center of a black hole.
The last time our physical model of the universe predicted an infinite value, we ended up discovering new physics eventually (the ultraviolet catastrophe). (Edit: ultrasound was a typo).
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I think you're referring to the ultraVIOLET catastrophe
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And an infinitely dense point in spacetime doesn’t necessarily exist: it’s just what general relativity predicts is at the center of a black hole.
If the singularity at the center of a black hole didn't exist, and was just extremely dense instead, would all of the other properties that we know is true about black holes be able to exist? For example we know that Sag A* and that one other black hole we 'imaged' give off no light, would that still be possible without a singularity?
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Nothing you said about black holes really contradicts what they were saying? Even if a star and black hole can have the same gravity, there is still a shell of space that once you pass you cannot ever return. I'm sure Superman could go into a star and come back out, not so much with a black hole.
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No. You can't ever get out of a lot of shit.
From a common star, if you can make your mass somehow be almost 0 and your speed being almost c, you can get out.
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I mean, the gravitational gradient is much higher. To me this kind of sounds like saying "there's nothing that special about a 10 watt laser, an LED lightbulb puts out the same amount of light", but a 10 watt laser is enough to instantly and permanently blind you.
Its true that there's nothing that special about orbiting a black hole, but I think its not really logically inconsistent (inasmuch as a superhero can be logically consistent) to say "even if superman could survive dipping into a sun he probably wouldn't be too happy if he stuck his arm into an event horizon".
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I knew before coming into the comments there would be a pendatic with this argument
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And you were right! Kudos to you!
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Why is nobody talking about how
marauding black death wrapped in a spherical gradient of tortured spacetime
is such a fucking cool sentence
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I'm just excited to see people having knock down drag-out fights about how scientifically accurate tumblr prose is on a comm that's not my responsibly to moderate!
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I suppose cosmic horror elder gods like Cthulhu and such are not all that far removed from the idea of a black hole. Particularly the ones that are less involved with Earth than Cthulhu is. Nobody is ramming a black hole with a fishing boat. But the early writing on them was done at about the same time as a lot of the foundational theoretical work on black holes (not the earliest stuff but I can believe that the writers didn't know about it)
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Yeah, Azathoth fits the bill in many ways.
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If I remember Lovecraft correctly the whole idea was that human mind can't comprehend such things. And black holes fit very nicely.
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black holes seem pretty comprehensible to me? like there's a lot of math and programming that's way harder to wrap your head around
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Also, extremely pedantic note - black holes were predicted by looking at what happens in the math at extreme densities, long before black holes were actually observed in space
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And some of the scientists who worked on those early calculations assumed it meant the physics was incomplete!
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Teachers: You can't divide by zero.
Nature: Hey guys, check this shit out.-
There are math models where dividing by zero makes sense. It's just that those models don't suit our world for now.
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Now get this: some scientists think black holes might have hair.
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Everything was hairy back in the 70's.
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But can you comb it all into the same direction?
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yes because they have a bald spot due to high testosterone levels
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Just FYI Superman has survived a black hole because the plot demanded it.
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Keep in mind that all the cliches about black holes are about non-rotating black holes, which don't exist in reality. In reality, a spinning black hole has a ring singularity, not a point, and behaves much weirder and even less intuitively than the hypothetical non-rotating counterpart as it smears out spacetime into taffy.
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Is it theoretically possible to shoot something through the ring? Or does the even horizon completely envelop it?
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It is, and you won't believe what happens!
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What? What do I look like, PBS Spacetime??
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the event horizon is effectively a sphere, like inflating a donut-shaped balloon (that can't pop). Eventually the middle hole is going to close like a sphincter (enjoy that imagery) and the whole thing will approach the shape of a sphere because that's what anything becomes when you inflate it hugely.
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The Black hole isn't a ring, it's a fuckin sphere, the ring surround it in it's equator. Grinded material more and more acelerated until almost the speed of light nearby the hole, from where it falls into the hole to end as something nobody knows. Like the swirl formed when you take out the plug of the sink, but the hole in the middle is a sphere.
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Our hopes and expectations == Black holes and revelations.
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And the superstars sucked into the supermassive
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graph function singularities exist as physical features in our world
Do they, though..?
As I (mis?)understand it, as a massive star begins to collapse, getting denser and denser, the gravitational gradient gets steeper and steeper... and time (from the perspective of an outside observer) gets slower and slower... to the point that, from our point of view, the full collapse (or maybe even any collapse below the Schwarzschild radius?) hasn't happened yet, and won't happen until the extremely distant future, beyond the end of the universe...
So, in that sense, from the point of view of "our world", no singularities (except possibly the big bang) would ever exist (yet), all of them being censored not only by event horizons, but by being shoved into the perpetually far future, beyond time itself...
And, speaking about event horizons, isn't the whole "light isn't fast enough to escape" concept a misinterpretation of sorts..? As I (again mis?)understand it, it's not a matter of speed, but of geometry... The way space-time is twisted in such a gravitational gradient, once you get past the event horizon there are no longer any directions pointing towards the outside.
Which is another from of cosmic censorship (or a different effect or interpretation of the above), preventing anything inside the event horizon from causally interacting with the outside universe...
So, if these singularities are hidden beyond sight, causally, visually, and geometrically isolated from the rest of the universe, and perpetually shoved into the far future... can they really be said to exist in our world..?
(Of course there's always the big bang, but we can't really observe that one, only its effects, and it's not necessarily exactly what the original post was talking about anyway...)
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I think you explain it pretty well, but one thing to add. Due to the General Relativity and thus spacetime it is actually not directions that all point toward the singularity, but as soon as you cross the event horizon all of your future becomes the Singularity, not as a point in space, but a point in time
https://plato.stanford.edu/entries/spacetime-singularities/lightcone.html
This points at that, you would also need to be able to travel faster than light and that would make you time travel backwards in time
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all of your future becomes the Singularity
There is some small burn-off Hawking radiation that escapes and gradually reduces the mass (and information content) of the black hole. Some of that would be you.
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Fun fact: the big bang was not a singularity.
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That was an interesting article. Thanks for sharing!
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The fact that there's some of them hurtling through space, unrestrained by the common movements of the rest of the galaxy, is really something to think about.
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It's in the same vein as gamma ray bursts. Could possibly cause problems, but space is so big, so heavily occupied by empty space, that the odds of ever encountering one vs just more empty space is almost infinity:1.
I mean, our planet is billions of years old and hasn't encountered a single one yet, based on the fact it's still comfortably in orbit around the sun.
Asteroids are far, far more concerning. Encountered a bunch of those already.
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The CW flash can escape from a black hole
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I remember reading this single page image from the flash where he was talking about how much he did in an atto second.
If that'd be true,nthe flash could create black holes at will or even by accident if he isn't careful
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Flash is such a hilariously overpowered hero, it's awesome
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GOOD point
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Idk, I don't think most scifi pushes the envelope of what we can imagine, rather it provides a convenient escape to galaxies less incomprehensible than the bewilderment of earth where the author can make a point about spacewar and unstoppable mindless empires.
shrugs
Scifi (like any other genre) needs to continually reaffirm its association with creativity, not assume because paper thin character types are fighting spacewars for feudal empires and space corporations that it counts as pushing the envelope of our imaginations.
/end side rant
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I've heard that 'our reality is made of math' before. Does this mean that we do in fact live in a simulation, even if that simulation wasn't necessarily programmed by 'higher dimensional' beings?
If that is the case, could we conceivably 'hack' the universal code and unlock cheat mode?
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We don't need to "live in a simulation" for "our reality to be made of math". Math could very well exist outside of anything, as a formal concept. This is the old debate asking whether math is invented or discovered. If it is discovered, then it can exist without any reality, as a pure abstract concept.
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It's confusing. I don't understand what the difference is between something which is made of 'a pure abstract concept', specifically math, and a simulation- which is also made out of math.
I'm not saying it's something ran on a computer somewhere, just that the abstract concepts that make up our universe, if it is "made of math", clearly has rules that it obeys- like the speed of light in a vacuum or the other constants. Which would seem to be analogous to parameters in a more traditional simulation. If 'math' is something that exists independent of sentient beings, couldn't whatever that is be the 'thing' that the 'simulation' is ran on?
I guess where I'm getting hung up is the idea that the universe can be 'made of' something that has no 'reality'. Am I just misunderstanding what it's meant by 'made of math'? Like even if math is 'discovered', how would that be any different than us inventing it, if it exists 'without any reality'?
To be fair, there is lots of stuff I don't understand, but I am trying- go easy on me.
I was being cheeky about the 'cheat mode' thing (unless it's real then I'm in).
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Plus, black holes may do contain universes. This year there was some evidence pointing that our universe is actually trapped inside one... ref: https://futurism.com/universe-trapped-inside-black-hole
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I heard it more like, the fact that our universe is expanding faster than light, means there are parts of the universe we can never reach, even at light speed, which is mathematically identical to the event horizon of a black hole, which not even light can escape from. There's not a singularity at the center of our observable universe, though.
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I heard it more like, the fact that our universe is expanding faster than light, means there are parts of the universe we can never reach, even at light speed, which is mathematically identical to the event horizon of a black hole, which not even light can escape from. There’s not a singularity at the center of our observable universe, though.
Just to add to this... It's not like there's an event horizon like with a black hole. It's just that in the amount of time it would take the light to reach us, there will have been more space "created" than the distance the light was able to travel. For someone living near the edge of our observable universe, there's nothing strange happening. In fact, we'd be at the edge of their observable universe, the edge of their "event horizon."
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There's not a singularity at the center of our observable universe, though.
Well, er, how would you know?
Perhaps the space inside the event horizon is so large, and the distance to the singularity so great, that the expansion we observe from our reference point appears uniform.
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thinking about the universe is already traumatizing
Where does it end? How are we floating? What if we fall? Where does it come from?
I don't think about that a lot so it doesn't give me anxiety
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that's the fun part, everything is always falling!
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They really drive home the point that we can't understand time
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What if black wholes are just pussy whole for our universe , plants are overies and we are the seeds . Some of us die because our mom took contractive pills
125 comments
I'm not an astrophysicist, but that ends up being the weird perception thing about them, right? Mostly they're like a star of the same mass, and then a few will get really big and be at the center of a galaxy, but the perception is that of a natural disaster.
Big ball of plasma in the center of the solar system that will definitely eventually explode and wipe out anything left alive on any surrounding planet? NBD. An object of the same mass but it's smaller so it doesn't shine? People picture it as being more immediately violent for some reason because the "light can't escape" thing sounds so wild.
Yeah, black holes in media where they are depicted as a giant space vacuum cleaner is a big pet peave of mine. Unless you get really close, nothing is remarkable about the orbital mechanics of a black hole. The equivalent mass star would have burned you up at a much further distance than the gravity starts to become noticeably wonky.
It's a shame that writers focus so much on the gravity and neglect accretion disks and astrophysical jets which do extend large distances and are visually stunning as well.
If we ever invent FTL someone is gonna make a black hole bomb.
also the way they bend light, a proper physically simulated depiction of a black hole is so fucking cool because it just kinda intuitively looks like it's so heavy it's bending spacetime around it!
To be fair I think "light can't escape" thing really just is that wild, it's pretty captivating. The idea of it being the death of a star, one of the most important things to all life we know about, only adds to that sense. Stars are massive billion-year explosions, yes, but they also bring warmth and light and beauty. Black holes are the death of all of that, even if it's not technically more dangerous from the same distance
It's not that light can't escape that is scary it's that the future of anything passing the event horizon changes to eventually end up in the singularity. Black holes are not just death, most of the things in the universe are death to us, black holes are literally the end of time.
The true death of that is more depressing than torturous: Heat Death.
Especially since we still don't know how information preservation works in a black hole. There are ideas yes but we still aren't sure if any of them are even right.
The sun isn't heavy enough to go supernova. (Unless it has a companion, but there's no evidence of one so far.)
It will still expand and shed enough stuff to effectively blanch whatever part of the solar system it doesn't actually engulf, though.
It doesn't even have to go supernova to kill everything, which is kind of the point.
Pop sci-fi seems to be fond of intermediate-mass black holes (EG Interstellar, Star Trek StrangeNew Worlds), and for something kinda the size of a star, they are "scary."
In other instances (like in TV Foundation), a close orbit to the accretion disk is a source of suspense.
And then there's the "stealth" aspect. Stellar-mass ones and below are very small and (potentially) quiet for something with the mass of a star, eg easy to stumble upon.
And in some very advanced universes (eg the online Orion's Arm), even with "hard" sci fi, swimming through a star's nuclear plasma is totally doable. But a black hole is an impossible boundry of physics, and an particularly extreme object useful for astroengineering.
They are like stars in the sense of orbital mechanics.
But a star can be completely understood by the laws of physics we know. While a black hole breaks our understanding and we have no idea what's going on in there.
It's the fear of the unknown.
I don't know. Isn't it rather that they were predicted by the laws of physics we know (or got to know with Einstein) and everything about them can be fully described and is known by our current understanding of these physics?
But I get what you mean. They are a symbol of the weird counterintuitiveness of the theory of relativity.