How would one exit a black hole?
from renamon_silver@lemmy.wtf to nostupidquestions@lemmy.world on 17 Aug 13:45
https://lemmy.wtf/post/26947405
from renamon_silver@lemmy.wtf to nostupidquestions@lemmy.world on 17 Aug 13:45
https://lemmy.wtf/post/26947405
Feeling like taking a vacation.
#nostupidquestions
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You wait for it to reach a critical mass and explode. Might take a little while.
Do they do that? Is that what the Big Bang was?
They don’t. They do evaporate though.
That’s a hypothesis though, right? They haven’t detected any yet afaik (which the article could make clearer in its introduction).
Yeah, it mentions it at the end under the “Experimental observation” section.
Yes, I know, but realistically, many (most?) people just want brief, general information, which is what the introductory paragraph is for, no? So I’d argue it should say “hypothesised” or “predicted” somewhere in the, ideally, first sentence.
It does say that it is a “model” and “predicted” in the first paragraph.
Okay, might have worded that better. It says “The radiation was not predicted by previous models” and “is predicted to be extremely faint”, not “it is predicted to exist” - and also “[it] is many orders of magnitude below […]” which sounds like a statement of fact. I realise this may be nitpicky but I don’t know if people who don’t know anything about the subject would interpret that as “we don’t really know if it even exists yet”.
It is difficult to be certain about unmeasured things. It would help everyone if those who don’t know anything about the subject would understand that science is about approaching clarity and the scientists are so zoomed out on some things that it isn’t always as clear as anyone wants. But scientists are still trying to answer the question. They are trying to help.
I agree, definitely. But here we are, the reality is that people read first paragraphs at best (which there can be valid reasons for) and take away “ah yes, Hawking radiation is a thing black holes do, science says so”. A reader who is interested further and has the mental capacities after working 8 hours 5 days a week to scroll down and read about experimental observations might also realise “oh wait, it isn’t actually clear whether it does exist” but you can’t expect that from everybody (unfortunate as that may be).
This particular instance may be harmless because it probably doesn’t affect anything in everyday life. But in general I think a first paragraph in an encyclopaedic source that wants to inform the general public should be very clear about it when a thing is hypothesised and hasn’t been shown to exist.
More or less. In my layman’s understanding: Black holes ‘evaporate’ slowly through Hawking radiation, losing mass as a function of their surface area (simplistically, particle/anti-particle pairs ‘pop out of nothing’ near the event horizon, one gets swallowed up the other escapes, this means a net loss of energy, which has to ‘paid’ by the black hole losing mass, think E=mc^2^).
Since a black hole behaves (geometrically) like any other sphere, the proportion of its area to its volume will grow as the black hole loses mass (i.e. it will have more and more relative area the smaller it gets), this process speeds up over time thus ending in what I guess you could call an explosion (more a whimper than a bang, to borrow a phrase).
Part 2 of your question: We don’t know.
Wouldn’t the hawking radiation need to be a higher rate than the black hole is absorbing matter?
Yes, the effect is extremely tiny and easily offset when a black hole is “feeding”.
Which will eventually happen to all black holes because the last things remaining will be black holes, so there would be no matter to absorb.
Which begs the question, what happens to the estranged particle that escapes the black hole from hawking radiation.
They’ll wander forever through an ever expanding space, meaning they probably won’t ever come across a different particle.
Eventually everything will reach equilibrium, aka the state where nothing moves anymore because everything it could react with is too far away to cause any reaction.
Which is why it would work with a small black hole, but not with a large one
You’re maybe thinking of white dwarfs. Black holes don’t do that.
depends how close you are, and not getting spaghettified.
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by entering a black hole nested in that black hole
space.com/…/is-our-universe-trapped-inside-a-blac…
Hmm. You might be causally disconnected from the grandparent reality, but you're technically still inside both child and grandchild.
isn’t that a direct contradiction? If I’m causally disconnected from a region, in what sense am I “inside” that region? I am causally disconnected from the past, am I in the past? I am causally disconnected from regions of space that are expanding away from me faster than the speed of light, am I “in” those regions in any sense?
They'll each boil off into their parent universes due to Hawking radiation once their respective parent universes reach heat death, so yes, each child is still inside its parent.
But try not to think about orthogonal timelines across causal boundaries or you'll give yourself a headache.
You evaporate over billions of years via Hawking radiation.
Try more like trillions of trillions of trillions… repeat a few more times.
Luckily time flies fast inside.
As if being shredded to atoms wasn’t harsh enough, you don’t even get keep your neutrons and electrons in this process. I guess it still counts as “exiting” the black hole, but just barely.
Well your information is preserved in the universe and that’s all any of us can really lay claim to anyway.
What if I have somewhere to be before then?
That assumes black holes aren’t the Big Bang white hole events of new pocket universes of the fizzy foam multiverse.
You could be part of a whole new universe! You wouldn’t know it, but how fun!
That’s actually not that hard, if we’re talking about a rotating black hole that’s sufficiently large (like the supermassive ones are).
With super massive black holes, you could pass the event horizon and not even know it. To you, everything would remain relatively (no pun intended) comfortable. You could live for a couple days, falling towards the singularity before the gravitational gradient becomes enough to rip you apart, thus ending your life.
Now I have a doubt. Could you have a stable orbit around the singularity but inside the event horizon? Or is the orbit speed above c?
Maybe you could live a comfy life there.
I would assume that anything that lies within the photon sphere could never have a stable orbit. The photon sphere is the point that light itself orbits the black hole and its 1.5x the radius of the blackhole itself. Anything closer to the singularity than this boundry is doomed to fall into the singularity as it would require faster than light speeds to maintain any stable orbit.
I wonder if anything could actually cross the photon sphere at all without getting vaporized by potentially billions of years of accumulated light that got stuck orbiting the black hole.
If I recall correctly, the photon sphere orbit is unstable, so there may not be a ton of photons there. “Unstable” in this sense means that photons in adjacent orbits tend to diverge away from the photon sphere orbit rather than toward it.
For Schwarzchild holes, the lowest circular orbit for massive objects is at 3 event horizons, which is above the photon sphere. There are unstable circular orbits down to 2 horizons. Black hole rotation reduces this altitude for prograde orbits asymptotically down to 1 horizon.
Hell, forget the photon sphere, even. Know that jet of energy black holes are thought to sprew out at their poles due to the material falling in to them? Imagine what that material is doing inside the event horizon. Whatever it is, it’ll be pretty violent, enough to call the moon slamming into the earth “relatively peaceful”. It would probably be more pleasant hanging out in the core of the sun than even an AU away from a black hole’s event horizon (and I mean on the outside).
Also, the event horizon is where light cannot escape. The “spacecraft event horizon”, or the orbital plane surrounding a black hole where a spacecraft couldn’t escape it is going to be much farther out, unless we can figure out ftl travel.
Which technology? Become a bigger AH than the black hole?
Magic
Literally, impossible. To exit the event horizon of a black hole, you’d have to travel faster than the speed of light. We know for a fact that anything with mass cannot travel at the speed of light. (And anything without mass MUST travel at the speed of light) Once you cross the event horizon, you’ve been entirely and irreversibly separated from the rest of the universe.
Does this also mean that black holes are totally indestructible?
Basically.
They slowly decay as hawking radiation, but there’s nothing you can do to speed up the process.
Well, there’s the hypothesis of a “naked singularity” whereas if enough charge or spin could be added to a black hole, the event horizon, aka, the black part of a black hole, could just vanish. This would expose the singularity at its center but its just a hypothesis. Or better yet, a thought experiment at best. This wouldn’t eliminate its mass though.
It’s not even about needing to exceed the speed of light. Once you cross the event horizon, spacetime around you is so warped that “out” doesn’t exist anymore. Point your ship in any direction and fire up your FTL engine; it doesn’t matter. No matter which way you try and fly your ship, you’ll be getting closer to the center. Once you cross the event horizon, there is literally no way out.
I love how mind bending it is imagining what lies inside a black hole. Everything we know about physics may essentially go right out the window beyond the event horizon.
You’re not the boss of me! I do what i want!
with a stronger blackhole next to your blackhole. just have a stronger pull.
its like how do u have bribed politicians not vote according to that bribe: bribe them with a bigger bribe.
go to the other end
Exactly, when you’re going through hell, keep going. Maybe you’ll find a white hole in the other end with a new universe to explore.
feed it taco bell
The singularity will pull you in, feet first, then the tidal effect will spaghettify you. You will be ripped apart atom by atom by those same tidal forces. You cannot escape the event horizon.
Good luck!
Perhaps op can escape in a form of electromagnetic radiation…
Through the gift shop.
<img alt="" src="https://lemmy.world/pictrs/image/33b239df-64ed-481f-9d52-68f19e3ae589.gif">
Generally speaking, as Hawking Radiation.
what if i want to use my legs afters
You’d have to build them first.
Anything more complex than an atom is going to be disintegrated before it even enters a black hole due to the intense energies at play at the interface.
Anything as complex as an atom will be disintegrated too.
You throw a big party in a place as far as your eyes can see. You call it the event horizon.
You just need water and magnets
With the assumption that we are alright in there, wait until it evaporates naturally. I hope you brought a lot of books, cause depending on its mass, it can take some time.
Only from an outside perspective. Inside the black hole it’s already next Tuesday.
Actually, it may be that it quite literally can’t take any time inside a singularity! As you approach a singularity, the spacetime curve representing the passage of time approaches zero, meaning that from your perspective, the universe outside the event horizon moves more and more impossibly fast, and from an outside perspective, you move more and more slowly until your motion appears to stop entirely.
At the singularity, our understanding of spacetime basically just shrugs in an infinite manner, puts on its hat, and clocks out for the day. It may be that, for the singularity, the entirety of time between the collapse of the star that formed the black hole and the eventual evaporation of the black hole due to Hawking radiation are compressed into a single instant, and no time at all passes for it.
So you might not need any books at all, because by the time you reach the singularity (which wouldn’t take a particularly long subjective time), it may well be the end of the universe. Hope you paid the meter.
(Edit to add: Now, probably not. Hawking radiation has to come from somewhere, meaning the particles that have been absorbed had to be converted into them at some point, and that can’t happen if those particles are also still matter (or whatever) in an eternal conga line at the singularity. But hey, our understanding of physics literally can’t be confirmed or denied inside of a black hole, so your fanfic is as good as anyone’s!)
Enjoyable read!
don’t fight against gravity by trying to fly directly towards the universe. Instead, fly parallel to the universe until you are out of the black hole’s pull, then angle back towards the universe.
No no no. You need to take the u-turn at the other end of the universe.
When you’re ready, you should see a bookshelf. Start messing with the books to send a message to your daughter and maybe she will help you.
Prerequisites: daughter
:0
Have 5D future humans put you in the tesseract, then you exit seeing your daughter on their deathbed while you barely aged a day.
Spaghettified… Mostly.
Space time gets so curved that literally every direction around you is the center of the black hole.
You look forward? Black hole center.
Behind you? Center
Up down? You guessed it
From your perspective, the center literally is the only direction you can go, deeper.
<img alt="" src="https://mander.xyz/pictrs/image/cd31a2a8-7426-427a-973c-d7c0d2fea279.jpeg">
Vacation is seeming further and further away.
The good news though is that so does work. So does anything, really.
Well, the end of it is, at least.
So if you walk backwards, every direction leads out. Easy!
Exactly!
Through a white hole.
(not kidding)
since black holes are incredibly common in the universe, if everything that went into a black hole came out the “other end” from a white hole, then it would logically follow that white holes would also be incredibly common. however, while white holes might exist, nobody has ever observed one, or found any mechanism capable of creating one, or evidence suggesting that they even exist, or have ever existed, or will ever exist. meanwhile, we have directly imaged the accretion disk around a supermassive black hole.
one definitely exists, the other is firmly within the realm of theoretical only, where it is expected to stay indefinitely.
Or if every Universe begins with a white hole, you now have a set of keys to the Multiverse.
To be fair, we only recently actually saw a black hole, and before that, it was just assumed to exist by its gravitational effects.
So what is it?
One wouldn’t
You can eveporate your way out of it, given enough time.
You just pop out the white hole on the other end.
The only direction is forward. Better hope it leads somewhere.
You go into a white hole, duh
As a jet of energy, assuming you haven’t actually crossed the event horizon
You’ll be slowly radiated out one half of an entangled pair of particles at a time. Arranging for reconstruction might prove difficult.
Find the Myotrope, invert your orthocameral orbit, grab your ankles, and hold on!
With space time snapshot machine I guess, you setup space time snapshot machine to take snapshot and setup detector on your body particles to roll you back from snapshot after your every particle is altered and it rolls you back to previous state. I think this should work.
And never trust it when it says “quick save” always make a manual backup!
I don’t know about exiting but I like Entering A Black Hole Backwards followed by Chilly Water.
Are you capable of moving faster than the speed of light?
or have a time dilation device from sg1, that is modified by replicators
Pretty sure even that wouldn’t work? Once inside all directions become further in, or all futures become further in, or some bullshit like that.
But travelling faster than light you can go to the past before you passed the event horizon.
Doesn’t matter once your breaking constants
Maybe my farts are
Real
That’s the fun part, you don’t.
You don’t.
same as you would anybody’s hole: just pull out.
you just walk out. might need to build a bridge first