What If You Fall into a Black Hole?

About Black Holes: Powerful, Extreme, and Weird#

So, black holes are basically the most powerful and extreme things you can find in the universe. They’re also super weird and complicated. You might wonder what would happen if you somehow fell into one, and what they even are in the first place.

To get it, we first need to chat a bit about space and time.

Space and Time: The Universe’s Stage#

Think of space and time as the big stage where everything in the universe happens. But this stage isn’t solid, and time doesn’t tick the same for everyone, everywhere. Basically, they’re relative.

Here’s the key:

Matter bends space.
Bent space tells matter how to move.

Put something heavy like stars and planets on this stage, and it sags underneath them. This sagging, this misshapen stage with all its little warps and dips, is what gives us gravity.

Black holes? They don’t just bend the stage; they’re like trap doors. They have so much mass that they create a sort of “no-go zone” in the universe where the usual rules change entirely.

How Black Holes Form#

Most black holes form when really, really massive stars die. We went into detail about this process in another video (our neutron star video, specifically), but the main thing to know is this: in the very final moments of these huge stars, their insides collapse inwards, or implode, at nearly a quarter of the speed of light.

This action packs an incredible amount of mass into a tiny space, making something so dense that it practically breaks the stage of the universe.

Just to give you an idea of the scale: a black hole with 10 times the mass of our Sun would only be about 60 kilometers across.

What a Black Hole Is (And Looks Like?)#

If you look directly at a black hole, well, it looks like nothing. The space under their control is blocked by an invisible, one-way border. This border is called the Event Horizon.

The Event Horizon forms a shell around a region of space.
Once you cross this border, you are shielded from the rest of the universe forever.
Why? Because the black hole’s “trap door” warps space so much that not even light can escape it.
With nothing escaping (especially light), there’s no way to get information from the inside, making it impossible to know what it truly looks like.

But we can still observe black holes! How? By watching their effect on matter. Things can orbit black holes, just like planets orbit the Sun.

Many black holes have glowing disks of matter orbiting just outside the Event Horizon.

This matter forms what’s called an accretion disk.
It gets unbelievably hot.
Close orbits can speed this stuff up to half the speed of light.
Even tiny amounts of friction and collisions between these particles heat them up to a billion degrees.
This makes the space around these black holes ironically incredibly bright.

What Happens If You Get Close (Or Go Inside)?#

Okay, let’s talk about what happens if you were brave (or foolish) enough to try getting close or even going inside a black hole.

First off, you’d see the weirdest things, like a funhouse mirror from another dimension. Matter isn’t the only thing that can orbit a black hole; gravity is so strong nearby that light can orbit too.

If you hover just outside the Event Horizon at a spot called the photon sphere, look in any direction, and you’ll just see yourself.
Look straight ahead? You’d see the back of your own head, because light from your back travels around the black hole and back to your eyes.

Gravity also messes with time itself.

The stronger the gravity, the slower time passes.
While you watch the universe far above you speed up dramatically, those far away would watch you in slow motion.
If you decided to fly away from the black hole after getting close, you might find that eons have passed for everyone else in the universe. It’s a bizarre, one-way time travel trip to the future where your loved ones are long gone.

Getting too close can also be incredibly dangerous. A painful death awaits you: spaghettification.

This happens because your feet, being closer to the black hole than your head, feel a much stronger pull of gravity.
This difference in pull is enough to stretch you apart as you descend.
It gets worse and worse; the pulling gets stronger, squeezing your body thinner and thinner.
Eventually, you’re reduced to a thin stream of hot plasma, kind of “gobbled up” in one final gulp, never seen again.

Now, spaghettification is mainly a risk with smaller black holes. They have much smaller radii, meaning the gravitational pull changes much more drastically over short distances (like the length of your body).

If you were to go to the center of a galaxy and find a supermassive black hole (these are way bigger), you might actually be able to experience crossing the Event Horizon.

Here’s how it would look from different perspectives:

From a Distant Observer: They would think they never saw you actually enter the black hole. They’d see you seem to stop just outside the Event Horizon and then fade away. The last light you emit trickles up and out, away from the Event Horizon.
From Your Perspective: The empty blackness of the black hole seems to rise up to meet you. Light from fewer and fewer directions can reach your eyes. The blackness wraps around you until your only view of the universe you left is a tiny spot of light behind you.

Inside the Event Horizon: A Broken Reality#

Here, inside the Event Horizon, space and time are totally broken. Seriously broken.

This is where theoretical real time travel might even be possible.
It’s probably a good thing nothing gets out! If anything could escape, it could create all sorts of time travel paradoxes and issues that could potentially “break” the universe in really bad ways.
As scary as the Event Horizon is, in a strange way, it actually keeps us safe from all that potential drama.

Whether you survived the trip to this point doesn’t really matter, because now there’s only one certainty: crushing death in your near future. Inside the Event Horizon, SpaceTime itself is so bent and warped that no matter which way you try to move, every step forward you take leads only towards the very center of the black hole. Trying to go in any other direction just brings you to the center faster. The only way to “survive” the longest is to do absolutely nothing.

The Singularity: The Ultimate End#

At the very center of the black hole, we find the Singularity.

This is described as a single point.
It’s where all the matter that has ever crossed the Event Horizon is crushed together.
It’s thought to be infinitely small.
There is no “memory” of the things that fell in and made it up. Stuff disappears down the black hole trap door forever.
The Singularity makes everything that falls in equal – whether it was a star, a planet, or you, it all becomes part of the Singularity.

This idea that the black hole loses all memory of what fell in (except for a few basic properties) actually breaks the universe in some cool ways according to our current physics. We’ve made another video about this specific problem if you want to dive deeper.

In a nutshell: everything that comes too close becomes black hole matter concentrated at the Singularity. Because it loses the details of its past, a black hole only has three properties:

Its Mass
Its Spin
Its Electric Charge

Everything else about what fell in is lost. They’re a lot like fundamental particles in that way – described fully by just a few things. This means that theoretically, every single black hole in the universe is the same in character. Sure, their masses are different, and some spin faster, but if we could put all their singularities in some kind of “magical physics museum,” they’d be identical, like electrons are identical.

However, just like fundamental particles, these three properties describing singularities are probably just the best ways we can describe them on paper with our current understanding, rather than being a truly accurate picture of reality.

Our current best theories about the universe, specifically General Relativity, just can’t describe or explain what happens at the Singularity.

The curvature of space becomes infinite.
Density becomes infinite.
Our rules just stop making sense. It’s like a “divide by zero” error in the universe’s math.

Because of this, singularities might not even exist as a point, or they might be completely different things than we imagine. But right now, this is all we know from the best predictions our current theories of SpaceTime give us.

The Reality: Spinning Black Holes#

Also, here’s something important: basically everything you’ve heard about black holes, even in this explanation so far, is usually about theoretical black holes that aren’t spinning. Why? Because the math is much easier for non-spinning ones.

But in reality, black holes are born from dying stars that were spinning extremely fast in their final moments. As far as we know, all black holes in the universe should be spinning right now, and at incredible speeds – up to 90% of the speed of light!

This means that in reality, black holes are even more messed up and complex than we usually give them credit for.

The singularities of rotating black holes are even wilder. The spinning causes them to swell outwards into a sort of ring shape, instead of a point.

This rotation is so powerful that space itself is dragged along. This creates another special region around spinning black holes called the Ergosphere.

In the Ergosphere, it’s impossible to stay still.
No matter how hard you try, you must move.
It’s like being caught in a rushing whirlpool of SpaceTime. The tide is irresistible, and the black hole forces you to orbit it, whether you want to or not.

The Future of Black Holes: Slow Evaporation#

Okay, so what happens to black holes over truly massive timescales, as the universe ages and eventually dies around them? Again, we don’t fully know, but we have some solid ideas based on our current understanding of physics.

This involves something called Hawking Radiation, which comes from Quantum Field Theory.

Quantum Field Theory tells us that even the empty “vacuum” of space is boiling with tiny quantum fluctuations.
These fluctuations are constantly creating pairs of particles and antiparticles out of nothing.
These pairs usually exist for just a tiny moment before crashing back into each other and annihilating.
But when this happens very close to the Event Horizon of a black hole, sometimes one particle falls in, while the other one escapes.
The escaping particle is what we call Hawking Radiation.

This Hawking Radiation is not the stuff that fell into the black hole; it’s new stuff being created near the edge. And ultimately, the mass of this escaping particle has to come from the black hole itself.

So, over incredibly long periods, black holes will slowly shrink and radiate away via Hawking Radiation.

As the black hole shrinks, the Hawking Radiation gets stronger, radiating away faster and faster.
Eventually, what’s left of the black hole evaporates completely in a final flash of high-energy radiation, kind of like a tiny nuclear bomb going off, and then… nothing.

But this process takes an incredibly long time.

A black hole with the mass of our Sun has a predicted lifetime of 10 to the power of 67 years (that’s a 1 followed by 67 zeroes!). This means it would take an unimaginable 10,000 billion billion billion billion billion billion years just to lose a tiny 0.00001% of its mass.
But most black holes are much more massive than our Sun. The most massive supermassive black holes at the centers of galaxies have predicted lifetimes of 10 to the power of 100 years.

How long is that? It’s impossible for our brains to really grasp these timescales.

Imagine an hourglass filled with one grain of sand for every single particle in the entire universe. If we waited for every 10 billion years for just one single grain of sand to fall to the bottom, by the time all that sand was gone, not even 1% of the lifetimes of these supermassive black holes would have passed. There is no good concept to help our brains wrap around these time scales.

Will We Ever Truly Understand Black Holes?#

Will we ever really understand black holes? Truly know what’s going on deep inside them? Honestly, no one knows for sure. We can only observe their effects from the outside, and our best theories right now probably get the insides wrong, especially at the Singularity.

But you know what? It’s okay not to know everything. It just means there’s still work to be done, mysteries to solve, and really big ideas to think about. And that’s a big part of why humans do science!

In the end, we can at least be certain that we have plenty of time left to think about black holes before the very last one eventually evaporates away.

Want to Keep Thinking About Black Holes? (Support the Creators!)#

If you’ve enjoyed thinking about black holes and want to keep going, you can do that by checking out some things the team who made the video you saw has created with love!

They have a shop with lots of cool, black hole related stuff:

A Black Hole Infographic Poster that teaches you all the black hole basics.
A Choose Your Own Black Hole Adventure Poster that takes you on a wild ride (and might leave you needing a hug!).
A Black Hole and White Hole Plushy (for those cuddle needs!).
They also just released some other new space-themed goodies:
- Super comfy Space Socks.
- Very shiny Space Pins.
- A new Tote Bag and Pouch Set.
They have many other great space products too, all designed with love and care by them.

Getting something from their shop is the absolute best way to support them directly while getting something beautiful in return. Because of support like yours, they can keep making detailed, elaborate videos like this one and release them for free for everyone to enjoy.

A huge thank you for your support!