How do black holes “consume” light?
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Light is made up of particles, which like all matter, can be affected by gravity.
Black holes are just big gravity spheres, which are so strong that even light can’t escape, so they look “black”. Just sucks in all the particles and holds them.
(some will argue about the nature of light, particles vs waves and such. don’t worry about it. This is ELI5)
Objects either reflect or emit light, which is why you are able to see them. When an object falls into a black hole, the light emitted by the object is pulled back toward the black hole, and therefore you cannot see the object any longer.
Lots of answers here a five-year old wouldn’t understand…
Have you ever done that thing with a comb where you use the static built up on it to bend the water coming out of a faucet? Black holes have gravity that’s strong enough to do that to light. There’s a ring of bright light around a black hole where you can see light curving around the shape of the black hole just like water curves around the comb as the static pulls it out of its original path.
And a black hole’s gravity is just like earth’s gravity where it’s stronger, and pulls you towards it faster, the closer you are to it. Except the gravity of a black hole is *so* strong that when things get close enough to them, they’re travelling at the speed of light. Because nothing can travel faster than the speed of light, we stop seeing the things being pulled by the black hole’s gravity.
There’s a video from Mythbusters where they shoot a ball out of a cannon from the bed of a truck. The truck is travelling forward at the exact same speed that the ball is shot backwards out of the truck. The ball just drops straight down because the speeds are equal. That’s essentially what’s happening to all of the light that should be reflected back to us from a black hole. It’s not consumed, it just looks like it because it’s reflecting back towards us at the same speed that the thing it’s reflecting off of us travelling away from us.
There’s more scientifically accurate answers, but this is one that a five-year old could probably grasp.
A small steel ball comes within the gravity of the Moon. It spirals in and eventually lands. It can’t get back out unless something accelerates it fast enough to escape the Moon’s gravity (escape velocity). In this case, that’s less than twice as fast as some rifles can shoot a bullet, so not crazy fast. If we designed a rifle for this purpose, or if we used a halfway decent rail gun, we could shoot that ball back out of the Moon’s gravity.
Light comes within the gravity of a black hole. The gravity is so great that the light goes to land on the black hole too, but now even the speed of light is below the escape velocity of the black hole’s gravity, so the light cannot escape the gravity to come back out again.
I know there’s no real “landing” on a black hole, but that’s the ELI5 explanation.
Very little light actually gets sucked into a black hole (and surprisingly little matter actually).
Really, just about any light that would have passed by the event horizon will get bent towards it, but will till ultimately continue past it, with its trajectory changed.
Even with matter, unless it’s falling straight in, it’s going to speed up its “orbit” as it gets closer to the black hole and the accretion disk is so intensely energetic from all the compression of matter that it actually pushes back and keeps most of the matter from falling in in any kind of timely manner.
A black hole is a deformation in space so acute, that it forces all lines inside the event horizon to only go inward. There are no physical ‘exits’ once you pass that point, the only possible direction is farther in.
The same way Earth “consumes” meteors. The light falls in and isn’t going fast enough to escape again, essentially.
Think of a trampoline, now put a bowling ball in the middle, notice it dips down around the ball. Roll a golf ball across, it will curve as it passes the dip from the bowling ball.
This is what happens to light as it goes past planets and stars, the gravity bends space like a trampoline, causing it to bend the light direction.
Now get a 1ton lead ball on the trampoline, it goes straight to the ground and the whole trampoline stretches down. Now try and roll a golf ball to the other side.
This is a black hole bending space, and the golf ball / light simply cannot get to the other side, it’s pulled down into the massive hole, or ‘gravity well’ as it’s called that it creates
Think about it, light hits thing -> light bounces off -> light hits our eyes and we see it. Well what if light hits thing -> light bo….. wait it never does because gravity is strong enough to forever pull it towards the singularity rather then let it bounce off/back out of the event horizon. Nothing can possibly move faster then a light particle. Thus, as its mass grows and the gravity becomes stronger, the event horizon expands.
From a physics stand point it makes sense but the requirements to create that scenerio are too insane to ever fully understand beyond what the numbers tell us. Only way to possibly “see” more is if we could harness the power of gravity which will never be possible.
Gravity so strong that spacetime is warped into a sphere. A photon directed perfectly perpendicular to the surface of this sphere cannot escape because acceleration of gravity exceeds light speed.
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