Can black holes “eat” matter indefinitely or is there a limit? Do they ever have trouble absorbing large masses or is it always the same?
In: 11
As far as we know, there is no limit to what they can absorb. As they get more massive their event horizon (the radius where even light can’t get away) gets bigger, but they never get “full”.
Depending on exactly what happens inside the black hole it’s either got an infinitely dense core, so it literally has no size and can hold as much mass as you like, or it’s just got an insanely dense core that’s so small that it behaves the same way and it doesn’t really make a difference.
A black hole is not a hole. It’s just stuff. A lot of stuff. It’s more stuff than you can possibly imagine stuffed into a very tiny point. Stuff attracts other stuff, that’s gravity, so a lot of stuff has a lot of gravity, even if it’s in a tiny container.
Imagine a one ton elephant in a hydraulic press, crushed down to the size of a sugar cube. That sugar cube still weighs one ton, and contains all of the bits that used to make up that elephant, just really really really tightly packed together and you wouldn’t want it in your coffee.
Now instead of an elephant, imagine our sun, pressed down to the size of a football stadium. It still weighs as much as the sun, and all of the planets still revolve around it at the same distance, so nobody’s getting sucked in, but if anything came close to the edge of where the sun *used* to be, it’s going to experience the same gravity as the sun used to give at that point.
This is the start of a “black hole”; it’s just so much stuff that it has so much gravity that anything close to it is going to get pulled in and become part of it, but it doesn’t look like it should have so much stuff in it because it’s been crushed down to a tiny ball.
You could, if you could push it around like a Katamari, use a black hole to “suck up” (i.e. crush into a thin shell) the entire universe, but since you can’t and since everything in the universe is so far apart from each other, it’s only going to ever be able to “eat” what’s very close by, as there’s much much much much much much more space (i.e. not stuff) than stuff in the universe and it tends to move apart from each other.
It can eat matter indefinitely.
Large masses, like a star coming in at once will likely swirl around the black hole creating a very high energy disk and some of that plasma may be launched away from the black hole in a jet instead of falling in. I don’t know exactly how it works but there is good evidence of super massive black holes spewing out giant jets of gas so in that sense there may be a sort of limit to how much gas a black hole can absorb at once without throwing a bunch of it out into space in the process.
[deleted]
As others have said, there is no known limit to the *amount* of matter a black hole can consume.
However, there is a limit in how *fast* it can consume matter.
The gravitational attraction from black holes is really strong, and that strength can cause matter falling in to rub and squish and compress, heating it up. That hot matter will start to glow brighter and brighter the hotter it is.
Eventually, the stuff falling in will be *so insanely bright* that the outgoing radiation is *stronger than the black hole’s gravity*.
All nearby matter will get blasted away by the radiation temporarily, until it cools down again, and starts falling back in.
This actually leads to a fun physics problem we have yet to figure out. We’ve discovered supermassive black holes that are bigger than they should be allowed to be. If we assume they started as regular black holes, because of that “eating limit”, they haven’t had time to grow to their sizes just from consuming other matter. Figuring out where these come from is still an active field of physics research!
As a black hole consumes matter it is basically trash compacted in the black hole and makes the black hole slightly larger, but it only “eats” things very close to it, most black holes have less gravity than a star. https://youtu.be/Y5XzPOrItaI
First things first, Black hole doesn’t suck like a vacuum cleaner. It is just a massive amount of matter squished in a very very tiny space. What it does is have a pull on another object due to gravity. So if our Sun is suddenly replaced with a black hole of the same mass, Earth will not get pulled in, but will keep on revolving around it as it currently does.
As far as we understand right now, there is no theoretical limit on the amount of matter black holes can accumulate. However, there is a limit on the rate on which a black hole can gobble stuff. Which depends on the size of the black hole itself.
Think of a black hole like a drain in your bathtub. When you pull the plug the water starts to drain, but not all of it goes down instantaneously. That whirlpool is called an Accretion Disk. The bigger the black hole (drain), the bigger the accretion disk (whirlpool). It doesn’t matter how large the tub is though. All the mass (water) will be drained eventually. The Black hole’s size just affects how fast it can eat, not how much in total as all eating does is make the hole larger.
Yes, they can grow indefinitely. There is no limit to their size. In fact, our universe could be inside one and not realize it. It’s difficult to tell.
Also, black holes have this peculiar trait where they grow exponentially as they aquire more mass. Earth turned into a black hole would be the size of a coin. The whole universe turned into a black hole would be roughly 14 billion light years across.
No limit.
It doesn’t get easier or harder to digest new stuff.
But it does get heavier, which helps.
Latest Answers