what if you fell into a black hole

How much do you know about black holes? What would happen if you fell into one? Imagine you’re exploring space, searching for a new planet for humans to inhabit, and you come across a black hole. Curious, you decide to check it out. Would you have any chance of survival? How would you get out? Would there be a shortcut to another universe? This is “What If,” and here’s what would happen if you fell into a black hole.

Despite its name, a black hole is not a dark, empty space. In his theory of relativity, Einstein predicted how black holes form. When a massive star dies, it leaves a smaller remnant core. If the core's mass is at least three times greater than the mass of our Sun, gravity overwhelms all other forces and turns the core into a black hole. But don’t let its name fool you—a black hole isn’t a hole at all. It’s a huge amount of matter packed into a very small space. Imagine squeezing four Suns into an area just 15 miles in diameter—the distance you can cover in a 30-minute drive. The gravity in such a place would be immense.

A black hole's gravity is so strong that even light can't escape, which is why you can't see one directly. However, you can detect it from the gamma-ray bursts it emits, known as Hawking radiation, discovered by Stephen Hawking. He theorized that black holes could be passages to another universe. So, if you fell into one, would you find yourself in an alternate dimension?

Every black hole has an event horizon, the point at which the gravitational pull becomes so strong that escape is impossible—the point of no return. If you found yourself outside that point, you’d see stars twisted around a perfect circle of darkness. As you start being pulled toward a black hole, you’d accelerate, moving faster and faster due to gravity. Here’s the first bad news for you, brave space traveler: the gravitational force of a black hole is extraordinarily strong. If you fell feet first, your legs would feel a stronger gravitational pull than your head, stretching your body apart.

Stellar black holes, the most common type, can stretch about 9 miles across and be as heavy as 20 Suns. If you were pulled towards a stellar black hole, you’d be torn apart before even reaching the event horizon. To survive longer, you’d need to choose a supermassive black hole, millions of times heavier than our Sun. In this case, gravity would pull both your feet and head with almost the same strength, allowing you to cross the event horizon unharmed. If you’re wondering where to find one, there’s a supermassive black hole at the center of our Milky Way galaxy, 165 quadrillion miles away—far enough not to suck in the Sun or the planets.

But don’t pack your bags just yet. Crossing the event horizon is only the beginning. At the center of a black hole lies a gravitational singularity, where density becomes infinite. You’d be squashed into this center and become one with the black hole. You wouldn’t be able to tell anyone about your experience. However, an observer outside the event horizon would see a different picture. As you fell into the black hole, you’d appear to slow down, get dimmer, and turn redder, eventually freezing at the event horizon. This happens because, at the event horizon, space and time swap roles. Time stands still, while space moves forward. You couldn’t escape any more than you could travel back in time.

Even when the black hole eventually died, emitting all the particles it had absorbed, including yours, it would be impossible to tell whether those particles were you. Stephen Hawking theorized that information about your body wouldn’t be lost. He suggested the existence of alternative universes with different histories. In one reality, you fell into a black hole; in another, there was no black hole. From outside the event horizon, it's impossible to be certain whether there’s a black hole until you fall in. If you crossed the event horizon and there was a black hole, it’s sayonara. But if you were in a reality where the black hole didn’t exist, you’d still be alive, just in a different universe. There would be no way to get back to ours.