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.
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!
If we ever invent FTL someone is gonna make a black hole bomb.
It’s already invented, just put enough mass in too little space. Don’t need a star like mass, any will do if you can compress it enough.
You don’t need much mass to simulate a black hole
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.
Or they are passages to other universes.
https://en.m.wikipedia.org/wiki/Wormhole#Einstein–Rosen_bridges
Still the end of time for our universe, like it mathematically is. And we haven’t found any white hole in our universe yet despite it probably being much easier than finding black holes or most of the other stellar objects.
Could the big bang be a white hole? And doesn’t it make sense the wormhole kind of meaning you “wait” in the black hole until the end of the universe and the beginning of a new one as it will look like time slows down for someone approaching a black hole for an outside observer but not for the person entering.
I don’t think we know how the end of the universe even from outside of the black hole would look like. If I remember correctly at some point even black holes may evaporate due to Hawking radiation.
As for the big bang being a white whole, there are a lot of problems. Like it would mean the universe started at one point in space and that’s the opposite of what we see that the universe started everywhere.
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.
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?
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.
Sort of. They were predicted by Einstein theories. But in a way so absurd that it was supposed to be just a faulty part of the theory when you push it to a extreme. Basically the “infinite collapse” that occurs and that should put all mass in a infinitely small space.
That cannot be true, it collides with quantum theory.
We have observed the space surrounding black holes, and that is spot on with the theory. But we know nothing about what occurs inside them. We don’t know the density of the singularity, it’s structure, how that matter behaves at quantum levels. We know nothing about that.
Once you enter a black hole is not only that you would be torn to pieces and pieces to atoms, we don’t even know if atom structure would even exist in there. Maybe even boson-fermion structure doesn’t even exist inside a black hole.
“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
“In a spherical gradient of tortured space time” is a great title for an ambient or very slow.and moody electronic music album.
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.
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).
I think you’re referring to the ultraVIOLET catastrophe
yeesh, what was the ultrasound catastrophe then?
That whole comment was a struggle to type on my phone at the time because the screen was wet, so at the end that one slipped though.
still, kind of funny wondering what an ultrasonic catastrophe might have been
It’s what OP’s parents call the first day they saw him.
aw thats kinda mean
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?
In General Relativity, the way to get gravity so strong that not even light can escape is with a singularity: a point of infinite density. So, either this infinity physically exists, and maybe we’ll understand how better, or General Relativity may be incomplete: a model that works well most of the time, but doesn’t represent reality correctly at the extremes of heavy mass and small space.
Or at least that’s how I understand it. This has more info: https://physics.stackexchange.com/questions/18981/why-singularity-in-a-black-hole-and-not-just-very-dense#18987
This is similar to the ultraviolet catastrophe. Physicists predicted black body radiation using their current physical models, with high accuracy at low wavelengths of light, but at high wavelengths, the predictions diverged towards infinity, which disagreed with measurements.
(Source: Wikipedia)Breakthroughs in quantum physics later reconciled theory with measurements.
One big difference with black holes is we cannot yet measure the actual density in the interior of the black hole. We just have the prediction that there is a point of infinite density.
Any physicists around here may have a better understanding than me.
I appreciate your detailed answer, thank you for taking the time :D
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.
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.
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”.
You’d also likely burn to death pretty early on in the process. Like, the moment you cross the event horizon, instant death.
Actually you wouldn’t notice anything special crossing the event horizon. You’d just continue to fall.
Sounds like they are referring to the photon sphere.
I assumed it would be further inward than the photon sphere because heat radiation is (also an assumption) easier for gravity to hold back than light. I don’t know how “heavy” a star’s heat is, though, so ¯\ˍ(ツ)ˍ/¯
Heat radiation are particles with a mass and a certain speed, they are all by definition heavier and easier to trap than photons.
In terms of escape velocity, nothing can try to escape faster than light.
I knew before coming into the comments there would be a pendatic with this argument
And you were right! Kudos to you!
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.
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
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.
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.
In one, you mean? They get you perfectly fine answers around one
There’s lot’s of issues with current physics, mostly in cosmology. String Theory was partly invented to describe the interior of a black hole. The characteristics of the Higgs field are still unknown. Gravity is still not unified with the other forces, despite appearing to couple with everything. Our current best models for the formation of the universe predict huge amounts of invisible matter, and we have no idea what that could be, from new particles to microscopic black holes formed in the first nanoseconds of the universe, to reinterpretations of relativity. Those same models also predict that out universe is dominated by strange energy inherent to space itself, which has no basis in the Standard Model at all. I wouldn’t call these perfectly fine answers.
And even if the nature of the interior of a black hole what the only issue, the final part of physics we haven’t explained, I would say we’ve thought that before. About a century ago, the scientific community though they had mostly solved physics. The last big question was why ultraviolet light didn’t extend out to infinite energy as predicted. Then photons happened and we discovered quantum physics.
At the close vicinity where they don’t actually agree if it’s inside or outside.
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
The comment above was about the singularity, so “the rest” clearly does not include the singularity
I don’t think “no interpretable meaning in physics” is a reasonable description, though. In classical mechanics, sure, but we’ve got plenty of physics that doesn’t work in classical mechanics
okay what does infinite density mean in avant-garde mechanics?
Non-classical mechanics includes things like quantum physics and (depending on who you ask) special relativity. They feel extremely counterintuitive but they provide pretty reliable explanations for how things work. That infinite density doesn’t make sense in our regular understanding of the world doesn’t necessarily mean it’s not a useful model. That doesn’t mean it’s necessarily true, of course, but the fact that it seems weird isn’t really important. It might just be that physics inside a black hole permit for something that we can best describe as infinitely dense
Infinite density doesn’t seem “weird”, it is meaningless and indicates that our model incomplete and simply cannot make predictions beyond a certain point. You don’t look at an equation that divides by zero and think, “maybe someday this will make sense.” It will never make sense because it will always be undefined, and you need to start looking for your mistake.
You seem to be suggesting that there is a non-classical physical model that resolves the paradox. But you don’t claim that any such one exists. The physics inside a black hole might be different than here on Earth, but mathematics is not. There is no mathematical way to interpret the singularity, and so there can never be a physical interpretation. The model is meaningless deep inside a black hole. We will not know what happens until we develop a more complete model, not a better interpretation of this bogus prediction.
I am not suggesting that there is a non-classical model that accurately explains the inside of black holes, I am saying that due to our inherent lack of any evidence we should not be immediately discounting the models that work exceptionally well where we do have evidence just because they give us results that feel weird to us. Quantum superpositions were also widely rejected early on because they seemed impossible to meaningfully interpret, and yet now we can make computers do maths with them
You don’t look at an equation that divides by zero and think, “maybe someday this will make sense.” It will never make sense because it will always be undefined, and you need to start looking for your mistake.
This is like saying that the equation of velocity = distance divided by time doesn’t make sense because if you travel somewhere in zero time then you have to divide by zero. The equation is correct and has physical meaning, it just so happens that moving somewhere always takes some time. We can understand just perfectly what moving somewhere in zero time would be, we just don’t know of any way to make it happen. Loads of useful and practically-applicable equations have vertical asymptotes. Maybe there’s something that prevents the inside of a black hole from collapsing to an actual point. Maybe space-time really does just collapse inside the black hole. The model would still be useful and mostly accurate, just incomplete
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?
The theories on why are a fair bit beyond my knowledge of physics, but I do know that they’re not necessarily the same kind of singularity. Inside a black hole (assuming our models are correct), spacetime curvature goes towards infinity. At the big bang, there may not have even been spacetime as we see it in our current universe, or whatever causes the expansion of spacetime may have been so powerful that it caused the earliest spacetime to not curve despite all the gravity
Different things.
The singularity of a black hole is located in space.
The initial singularity of the big bag happened “everywhere” the whole universe was supposed to have infinite density.
The mass of the black hole is finite. It’s very dense but it have a quantifiable amount of mass.
For the big bang the mass was also infinite as far as we know. Everything was singularity, every “energy” in your body was part of that infinitely large singularity. Not only everything but everywhere. Where you sit there was singularity during the big bang. As far as we know every single point in space was part of the initial singularity. We don’t come from a single point that exploded towards empty space. Expansion is more like the surface of a balloon. Maybe it’s better to think of it as stretching rather than expanding.
Beyond that we don’t know much about both, there are barriers which prevent direct observation of both.
The expansion of the universe is a completely different matter, as it’s not only expanding, it’s expanding faster that out gravitational models predict, like the universe is not only “ignoring” black holes, it’s expanding despite all observable matter, and all untraceable matter (dark matter), and it’s expanding faster and faster driven by an unknown phenomenon we call “dark energy” for giving it a name, because we have remotely not idea of what’s going on.
The initial singularity of the big bag happened “everywhere” the whole universe was supposed to have infinite density.
If the density throughout all space was truly infinite, then the volume of space had to be ZERO. Otherwise the density would have been a very very large but finite number. And if it were infinite and non-zero volume, no amount of inflation would cause it to stop being infinite. Infinity divided by any positive number is infinity.
There are no naked singularities
But I read there were naked singularities in my area.
It’s a scam, you get there and find it’s all horny housewives.
A hole is a hole.
Why is nobody talking about how
marauding black death wrapped in a spherical gradient of tortured spacetime
is such a fucking cool sentence
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!
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)
Yeah, Azathoth fits the bill in many ways.
If I remember Lovecraft correctly the whole idea was that human mind can’t comprehend such things. And black holes fit very nicely.
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
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
And some of the scientists who worked on those early calculations assumed it meant the physics was incomplete!
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.
Now get this: some scientists think black holes might have hair.
Everything was hairy back in the 70’s.
But can you comb it all into the same direction?
yes because they have a bald spot due to high testosterone levels
Just FYI Superman has survived a black hole because the plot demanded it.
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.
Is it theoretically possible to shoot something through the ring? Or does the even horizon completely envelop it?
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.
It is, and you won’t believe what happens!
…
What? What do I look like, PBS Spacetime??
userface checks out
https://www.pbs.org/video/how-black-holes-spin-space-time-klqijt/ talks about passing through the ring
Gracias, amigo
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.
You are describing a Schwarzschild black hole. I am describing a Kerr black hole. A Schwarzchild black hole’s singularity is not a sphere, it is a point. Because a Kerr black hole forms a ring, there is a path where gravity partially cancels out, and so the event horizon is not spherical.
Schwarzschild black holes describe black holes in a simplified state in which we don’t expect to find actual objects. It vastly simplified the math, and for decades no one was able to work out the more complex situation we do expect to find in reality. My point above was that popular understanding of black holes is based on Schwarzchild black holes, and so a lot of the tropes don’t fully grasp how weird real black holes are.
The original comment were referring to the ring singularity which is different from the accretion disk.
The singularity is unseen, we suppose it’s a ring in rotating back holes, but we have no idea. As anything inside the event horizon, we cannot see what’s going on in there.
The accretion disk is the disk of matter falling into the black hole, it’s outside the event horizon and can be observed.
Supposing the singularity as an unidimensional something what we don’t know. In any case we can’t see the black hole as such, but the gravitation it causes, form a sphere arround the singularity, visible as such by the accretion disk. If not, we only can observe an black hole by its influence, eg, the gravitation lense effect.
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Our hopes and expectations == Black holes and revelations.
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…)
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
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.
Fun fact: the big bang was not a singularity.
That was an interesting article. Thanks for sharing!
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.
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.
The CW flash can escape from a black hole
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
Flash is such a hilariously overpowered hero, it’s awesome
GOOD point
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
