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How Do Black Holes Work?



Black holes are possibly the most mysterious objects in the universe, and their name doesn’t really help their reputation. Of course, it’s also a little misleading. Black holes aren’t really holes at all, but instead they’re areas of incredibly strong gravity resulting from (we think) a singularity. This still doesn’t answer the fundamental question: how do black holes work? Here’s what we think we know:



1. First, the black hole is formed.
Black holes don’t just appear. They have to be created by cosmic processes just like everything else. They are most commonly formed when a massive star (far more massive than our own sun) dies and collapses in on itself. All that mass crams together, becoming denser and denser.

2. When mass is squeezed into an infinite density, you get a singularity.
A singularity is, in essence, a point in space with infinite density. It may seem ridiculous to say that anything in reality is infinite, but in physics, not everything makes sense. Black holes exist, therefore the properties we have predicted should exist in some form.



3. Strong enough gravity can stop anything from escaping, including light.
So a black hole is really a singularity. Where does the black part come in? A singularity has infinite density, which translates to an incredibly strong gravitational field. Anything nearby is pulled in by the force of gravity, just like on Earth. However, unlike on Earth, that gravity is so strong that it can stop light from escaping. That’s why the area is black; there’s no light escaping from it, so we can’t see it. We can only see what is around it.
 
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Jan 17, 2020
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I keep hearing all these storys about nothing can escape a blackhole but in the next paragraph they say beems of quasars shoot out of it and other stuff also. So how can both be true.
 
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Dec 11, 2019
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I keep hearing all these storys about nothing can escape a blackhole but in the next paragraph they say beems of quasars shoot out of it and other stuff also. So how can both be true.
I like my theory on how a black hole becomes another universe on the other side of it. But precisely someone said a black hole isn't a hole but yea how would quasars shoot out of it?
 
May 28, 2020
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I'm having trouble reconciling these three things I've heard about black holes:

1) If you fall into a sufficiently large black hole, you won't experience anything in particular when crossing the event horizon. You'll have some time to experience being inside the black hole until tidal forces eventually grow dangerous.
2) Someone observing you falling into the black hole from the outside will never actually see you fall in, but rather observe your clock slowing down more and more, as all signs of you will grow weaker and longer in wavelength in an asymptotic approach to the event horizon.
3) All black holes, even the largest, eventually "evaporate", even if that won't fully happen for ~10^100 years.

My amateur interpretation of the first two items is that as you fall into the black hole, in your own frame of reference, the universe you leave behind will rapidly age from your perspective. Once you cross the event horizon, all you once knew will essentially be infinitely in the past, and you will then be in what could be considered the infinite future to the rest of the universe.

If I consider the third item, however, it seems that this infinite future can't exist, at least not inside the black hole. The black hole falls apart before then.

This leads me to guess that you might not ever be able to experience the inside of a black hole after all. Rather, you'd simply disintegrate as you cross the event horizon, scattering your mass across the distant future.

Is there any merit to this speculation?
 
Nov 16, 2019
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I keep hearing all these storys about nothing can escape a blackhole but in the next paragraph they say beems of quasars shoot out of it and other stuff also. So how can both be true.
Those beams are immediately before the event horizon, therefore not "in" the blackhole
 
Jun 1, 2020
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One of the problems associated with blackholes is that our language isn't great about "eschewing obfuscation". Black holes form when the gravitational field of incredibly dense matter becomes the dominant force, so more of an implosion occurs vs., say, squeezing as would be from an outside force pushing in. But that's just a nit and not something that trips us up much.

I suspect that a singularity is more in the suppositional category than a true scientific hypothesis, but I could be wrong. I'm being a bit pedantic of me to say it, I suppose, especially since it's so popular. But the idea of a singularity for the BBT (Big Bang Theory) doesn't seem to pass the true science test. Physicists say that when the rewind the clock past that of a Planck unit of time that the wheels go flying off the wagon -- their math results shoot toward infinity, which means they don't have the math to address this spacetime point in the universe. So I would assume all singularities of infinite density -- whatever that means -- have the same problem. [I'm not a physicist and many of them aren't GR experts.]

The safe passage through a SMBH (Super Massive Black Hole) seems to be mainstream science since the gravitational gradient is determined to be relatively gentle.
 
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May 27, 2020
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One of the problems associated with blackholes is that our language isn't great about "eschewing obfuscation". Black holes form when the gravitational field of incredibly dense matter becomes the dominant force, so more of an implosion occurs vs., say, squeezing as would be from an outside force pushing in. But that's just a nit and not something that trips us up much.

I suspect that a singularity is more in the suppositional category than a true scientific hypothesis, but I could be wrong. I'm being a bit pedantic of me to say it, I suppose, especially since it's so popular. But the idea of a singularity for the BBT (Big Bang Theory) doesn't seem to pass the true science test. Physicists say that when the rewind the clock past that of a Planck unit of time that the wheels go flying off the wagon -- their math results shoot toward infinity, which means they don't have the math to address this spacetime point in the universe. So I would assume all singularities of infinite density -- whatever that means -- have the same problem. [I'm not a physicist and many of them aren't GR experts.]

The safe passage through a SMBH (Super Massive Black Hole) seems to be mainstream science since the gravitational gradient is determined to be relatively gentle.
Now it's clear to me. Thanks for sharing some brief information.
 

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