# What are black holes and what happens to the things that get swallowed up?

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What are black holes and what happens to the things that get swallowed up?

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They are regions of space where matter has been compressed so densely that it has a significantly large “event horizon” inside which, not even light has enough energy to escape. They can have huge accretion disks of matter around them and produce strong gravitational lensing, so if you were close to one it could potentially look something like the one in *Interstellar* (which would be totally awesome.)

What happens to things that get swallowed up? As far as I know we can’t be sure, because no information can leave the black hole~. But presumably objects get reduced to atoms by the powerful gravity and added to the black hole’s mass.

~I’m not 100% certain of this thanks to the decay they undergo, someone correct me if I’m wrong.

Super heavy dense points in space where gravity is so intense anything passing a certain point can’t escape it’s gravity.

We don’t know what happens really as we can’t observe it, but we can make assumptions based on observations of what gravity does and some math around the warping of space time… Essentially they get torn to basic building blocks and become apart of the whole energetic Smoosh

The heavier things are (think stars and planets and so on), the more influence they have on other objects via gravity. If you imagine a rocket leaving the moon, you would expect it to take less thrust compared to a rocket leaving the earth. Your rocket needs to be very fast if you want to leave a heavier planet or star.

Ultimately the speed you need to be is related to how heavy the star is, and also how close you were when you started. Unfortunately the universe has something like a speed limit, the speed of light.

You could imagine an object so heavy that if you’re close enough, you’d have to travel much faster than the speed of light to escape. Such an object would need to be very heavy, but also very small, for you to get that close in the first place. Therefore, it has to be very very dense.

For reasons beyond a 5 year olds understanding, light can be affected by gravity too, even though it’s massless. So an object dense enough can suck in all the photons around it too, thus a “black” hole.

As for what happens when you’re sucked in, the simplest answer is we don’t really know…

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A black hole is what you get when enough mass is collected together.

Mass produces gravitational force that pulls on other masses, trying to collect them together. Gravity has a very long range but is relatively weak, meaning masses pulled together will just bump up against each other. The atomic forces of the atoms will repel each other so even though gravity is still pulling them together they can’t actually occupy the same location.

This is how things work for collections of mass up to a certain size. Things like fusion where huge amounts of heat and light are released (stars) complicate things but generally it is mass being pulled together until it can’t anymore.

If you increase the amount of mass even more things start to get weird. Eventually you can end up with a neutron star, a ball of mass composed entirely of neutrons. Instead of the normal atomic structure of a nucleus of protons and neutrons with electrons forming a field around it, a neutron star is just neutrons crammed against each other as closely as they would be in the nucleus of an atom. Gravity is so strong at this point there isn’t room for anything else. The only thing preventing the neutrons from getting closer is the Pauli Exclusion Principle, which simply put describes the concept that you can’t have two identical things in exactly the same place. The building blocks of matter have certain fundamental “quanta” that make them up, indivisible values. It seems that identical combinations of these values can’t coexist in the same place, and this limits how closely gravity can pull them together.

But what if you get even more mass and consequently more gravity?

This is where things start to get really weird. Gravity isn’t just a force pulling masses together. Instead that is just the most easily observed aspect of what it really is. In truth humanity doesn’t really understand gravity fully. Gravity causes the warping of spacetime. For example if you have two parallel lines and one of the lines passes close by a mass than the other, those lines will no longer be parallel. It shifts the underlying structure of space itself; not “vacuum outside Earth’s atmosphere” space, I mean volume of the universe.

When there is a lot of mass this warping of spacetime gets fairly dramatic. The path of light is significantly bent, or rather the light is continuing to move in a straight line but to an outside observer that line is curved. Eventually with enough gravity the warping of space is enough that while there are directions which point closer to the mass, there are none that point away from it. This is a black hole, and not even light can escape moving close enough to it.

From the outside the black hole is just a completely black circular spot. From any direction you see the entire expanse of the “event horizon”, a spherical boundary where the gravity is strong enough to warp space such that light can’t escape. Any mass can be modeled as originating from a point when at a distance, and black holes are no exception. This conceptual single point is a “singularity” and various theories exist about if the mass actually is concentrated in a single point or if there is more space inside the black hole than appears from outside. There seems to be literally no way to know though.

Simply – Extremely dense objects, their center is called a singularity. It’s a point in space with infinite density created by extremely high gravity. There is no difference between mass and energy there.

Around the singularity an event horizon is created. Event horizon is the black sphere you see when you think Black hole and it consists of… nothing. It’s just a radius where the gravity pull of the singularity is strong enough to even suck in light. It is impossible to leave the event horizon when you cross the edge.

If you would get swallowed up, let’s assume you’re going feet first, at some point the difference of force between your feet and your head would be so great that that it would start tearing your body apart atom by atom from the bottom up. Your mass would then join the singularity.

Let’s try to keep this ELI5, shall we?

You know how the Earth has gravity? It turns out all matter in the universe has gravity. The more matter you have in one place, the stronger the gravity, which is why gravity is lower on the Moon than it is on Earth. Less matter, weaker gravity.

A “Black Hole” is nothing more than a point in space with a *lot* of matter, and therefore a *lot* of gravity. They aren’t “holes” in anything, there’s nothing on “the other side,” etc. They’re called “Black Holes” because the gravity is so powerful that even light is affected by it’s pull. I *looks* like a hole in space because there isn’t any light reflecting off of it for us to see.

As far as what happens when it pulls something in? In some ways, it’s no different than when the Earth pulls down a meteor. That meteor gets added to the mass of the Earth. Same concept for a “Black Hole,” whatever can’t escape its gravity get added to its mass (and therefore increasing the gravity). There are a *lot* of different theories about what happens to that matter under such extreme gravitational forces, but the truth is nobody really knows becase we can’t replicate the conditions in order to study them, and even if we *could* replicate them, we *still* couldn’t study them because we wouldn’t be able to see anything.