So a black hole has incredible density, alright then. What happens when something falls into one?
Nothing tranquil for sure. In fact, the result of stars being swallowed up by a black hole creates one of the most violent reactions in the universe. The massive friction between the matter orbiting the mass creates heat that is near incomprehensible. And luminosity that puts not just stars, but galaxies the shame.
Although it should be said that such objects cannot exist without the presence of a galaxy. In fact, they only form in particular galaxies, ones which contain what are referred to as, "Active galactic nuclei". These are galactic centers that are, well, active.
Meaning it contains a lot of stars in a tight central area. Such stars are eaten up by the galaxy's central black holes. And as this happens we get a disk of material spiraling to its doom with its own name. A Quasar.
Many black holes, and even neutron stars, have accretion disks, disks of material being pulled into the main body. But only when they shine with brilliant glow due to the presence of a larger quantity of material do they become proper quasars.
These objects tend to just outstretch from the event horizon, meaning they don't end up much wider than it. Which for some black holes could mean being planet sized. But the supper massive black holes at the center of galaxies are much larger than that. Their event horizons can be equal in diameter to that of the sun, and beyond.
But the quasar's diameter doesn't end their reach. The black hole, with a not totally understood process. Shoots material outwards in powerful jets going in two opposing directions. These jets travel for some considerable distance, as in, several light years, stretching away from the galaxy they reside in. And nearest to the black hole, can reach temperatures of, grab your armrest, Ten Trillion degrees. Kelvin, that is.
There is no perspective on this one, there is nothing to compare this to that even puts in into any remote field of understanding.
The core of the sun is around say, 15 million kelvin. The initial temperature in a supernova can be as high as 100 million kelvin. And for about 0.00014 nano seconds, the hadron-collider in Switzerland made a single particle heat to about 5.4 trillion degrees kelvin.
Quasars are continually staying 10 trillion degrees for millennia, or even millions of years.
Unrivaled, the most powerful objects in the universe.
So enough about quasars, and onto another idea, what would happen if you fell into one of these light prisons yourself?
Well, it depends.
We don't know anything for sure, but chances are, you'd be dead, very dead. And surprisingly the newer and less massive the black hole the more screwed you'd be. When the black hole is super-massive, you'd stay farther away from the point of mass for a longer time as you'd move towards it, since the event horizon is bigger. You'd likely pass through it alive and get swallowed in one big gulp. But with a smaller one you're closer to the point. Therefore the force on any body parts closer to the center would get stretched and ultimately you'd end up as a strand just a few atoms thick. Once again, this effect was so fittingly named spaghettification.
Another weird thing would happen. Assuming it was a bigger black hole and you lasted past the horizon. One would see some odd effect as they moved closer. Time itself, would speed up. At least everything in the distance would. You'd feel like you're moving at a consistent speed. And to the outside viewer watching you fall. They see you slow down, look like you practically come to a complete halt. And you'd also look red, because light trying to escape would lose its energy and shift to a longer wave-length.
But what's all this time changing stuff I speak of? Are black holes time machines?
Kind of.
Time is relative to the fabric of space, gravitational waves detected as late as 2016 prove that Einstein was right in saying that this affect was real. But on any man approachable scale, it is minimum. Objects of mass dilate time.
So an object like a black hole will dilate time more than anything else. It will essentially allow someone falling into it to witness the universe fly in front of them, witnessing billions of years in just a few seconds. Weird indeed.
All this time stuff is a bit too abstract to really think about with intellectual honesty. It just makes no sense to the confines of the human mind, so it's best we move on.
But in moving on. I move to a final message about black holes, and space and reality in general that black holes act as a perfect example of.
We, as humans, as mortal creatures with limits to our senses for the longest time knew nothing more than what we could see, feel, hear, etc. As we advanced, we came to a point where we could use our incredible minds to build machines that revealed what we could not see with these senses. Machines that detected light of all kinds, beyond visible forms. We saw X-rays, infrared, ultra-violet, radio waves, gamma rays. . . We saw what was to weak for us. Light from stars farther than what our 6mm pupils could pick up on. And in doing so, our collective ego's inflated, there was a point in which humanity realized we could do more than we used to be able to, understand more. But as our nature follows, understanding more to us equaled understanding it all. To us, nothing was out of our reach of comprehension. How could it be? When not a single form of light remains invisible to us. When the behavior of objects floating through the vacuum of space is understood with our astrophysical laws. Then along comes the entities known today as Black Holes. Objects argued over their existence, believed to be a non-practical effect of relativity. It is well believed today by scientific historians that many scientist argued against black holes because they knew they'd destroy the reputation scientist were given that they could understand anything. How can something that emits no light, no magnetic field, something that couldn't be photographed to show in the news. How could they begin to understand it, let alone convince the public that they were objects that human minds had seized comprehension of from day one? The answer is, they couldn't. Because they couldn't be truthful, the fact is. Black holes are not fully understood, and very well may never be. They go into an area where, in spite of all our technology and light detection, remains firmly beyond our reach. The cavity in our universal understanding brought about by our mental limits. Our inability to comprehend, not inability to examine. Black holes represent a part of the universe that is beyond the reaches of science, something we are blinded from understanding not because we aren't smart enough, but because we only know a limited number of ways of understanding the universe. Black holes break all of these means of understanding. They are simply, beyond humanity. And this should be a lesson, a lesson that, its not always about intelligence, skills, or knowledge, or any individual trait of you on a spectrum with everyone else. Sometimes the only thing that's truly limiting your understanding or accomplishments, is the fact that you're human, and frankly, accepting that puts you in a much, much better place.
Image sources:
https://www.nasa.gov/feature/goddard/2017/collapsing-star-gives-birth-to-a-black-hole/
https://en.wikipedia.org/wiki/Quasar