Black holes are the most massive objects in the universe. So massive that nothing can escape! But what if you fell into a black hole?
Black holes are gigantic objects that have an enormous gravitational attraction. They are the remnants of dead stars.
After a star exhausts its nuclear fuel, its core collapses into an unimaginably dense matter, a hundred times denser than an atomic nucleus. That’s so dense that protons, neutrons, and electrons are no longer discrete particles.
Black holes are pitch black, and that’s because they don’t reflect light. They actually attract it. No material, or light, can escape its gravitational attraction.
But there’s still something that manages to escape. The event horizon, the boundary beyond which nothing can escape, is ablaze with energy. Quantum effects at the edge create streams of hot particles that radiate back out into the universe. This is called Hawking radiation, after the beloved physicist Stephen Hawking, who predicted it. Eventually, the black hole will radiate away its mass and vanish.
The only reason why we can detect these gravitational goliaths, however, is that they’re feeding on stars or gas clouds that stray too close to their event horizon. At the center of it lies what we refer to as the singularity–a single point where gravity is so intense that it infinitely curves space-time itself. And this is when the laws of physics cease to operate. That means all theories about what lies beyond are just speculation.
It could be another universe! The opposite of a black hole! A white hole that spews things eaten by black holes, maybe! We can theorize, but it’s still a mystery.
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However, when someone asks what would happen if a human fell on a black hole, most would probably expect to die instantly. But the reality is way stranger than that!
If you were to come too close to a black hole, you would get spaghettified. Sir Martin Rees coined the term ‘spaghettification,’ which is a perfectly good way to put it. You’d eventually become a stream of subatomic particles that swirl into the black hole.
If you jumped into a black hole, feet first, the gravitational force on your toes would be much stronger than that pulling on your head. And as you accelerate toward the black hole, gravity would stretch you so much you’d be spaghettified. The closer you’d get to the horizon, the more you would appear to an observer to move in slow motion. But actually, as you fell into the black hole, you would approach the speed of light. Eventually, you would reach the event horizon and that’s when an observer would see you freeze. Just like hitting the pause button.
Before you’d ever cross over into the black hole’s darkness, you’d become ash.
And then, nothing. No stretching, slowing, or scalding radiation. That’s because you would be on freefall, meaning there would be no gravity. And believe it or not, this was Einstein’s “happiest thought”.
When Einstein visualized a universe where gravity was not a force but a geometric property of curved spacetime, warped around massive objects, he called it “the happiest thought of my life”.
So, as you fell into a stellar-mass black hole, you probably wouldn’t worry much about the mysteries you might’ve been able to unlock on “the other side.” You’d be as dead as spaghetti-shaped doornail hundreds of miles before you hit the singularity. It would be a rocky ride as your matter perturbs the environment and the spacetime undulates.
The reason we know this is because astronomers actually observed something similar to this. In 2014, several space telescopes observed a star passing too close to a black hole. While the black hole stretched and shredded the star, some of the material fell beyond the event horizon, while the rest was flung back out into space.
Now let’s theorize for a moment.
In case you’d fall into singularity still alive, you would theoretically be able to see out into surrounding space, but no one would be able to see you once you passed beyond the event horizon. Even if you tried to shine a flashlight out, the light would fall back down into the singularity with you.
As you fall into the black hole, you approach the speed of light, and the faster you move through space, the slower you travel through spacetime. So, while falling, you’d be able to see every object that has fallen into it in the past. And if you looked backward, you’d be able to see everything that will ever fall into the black hole behind you.
Long story short, you’d get to see the entire history of that spot in the universe simultaneously, from the Big Bang all the way into the distant future.