problem in physics.

For decades,

scientists have been mystified

about what happens to stuff

that falls into a black hole.

The quandary is called the black hole

information paradox,

and it has stopped physics in its tracks.

But in recent years,

scientists have made a breakthrough

that may finally solve the puzzle

and begin to show

how black holes really work.

To understand the paradox,

we have to go back to Stephen

Hawking's big idea.

Just like a puddle of water

out in the sun,

a black hole will slowly shrink.

Particle by particle

until nothing is left at all.

His discovery

originated in quantum physics,

which shows us that

empty space isn't actually empty.

Instead,

pairs of so-called virtual particles

continuously arise out of the vacuum.

These pairs usually stay together,

except for the unlucky

few that arise on either

side of a black hole's boundary

its event horizon.

In that case,

one member of the pair

can get trapped within the horizon,

while the other carries energy away.

Eventually, this escaping energy shrivels

the black hole down to nothing.

The only problem with this scenario

is that if black holes can be destroyed,

then so can all the information about

what fell into them.

That seems to break

a fundamental law of physics,

which says that information

can never be destroyed.

What gives?

For nearly 50 years,

physicists were stumped by this problem.

But in the past

few years,

a unique solution has revealed itself.

Wormholes.

Wormholes are theoretical

bridges in spacetime

that connect to distant spots

through a shortcut.

Wormholes

sound like something out of a science

fiction movie,

but they are real

predictions of Einstein's

general theory of relativity.

Recently,

a new breakthrough

on black holes happened when scientists

considered the possibility

that the inside of a black hole

could be connected

to the inside of another black hole

via a wormhole.

Such a connection would be rare,

but it's theoretically possible.

And according

to the rules of quantum physics,

everything that can happen does happen.

A particle doesn't simply travel

along one particular path

from point A to point B

it takes all of them simultaneously.

Wild but true.

The same thing seems to be the case

for black holes.

All of the possible

weird configurations of spacetime

that could occur within them,

including wormholes, do occur

when physicists added wormholes

to the picture. A strange thing happened.

Information

didn't seem to be

completely destroyed anymore.

Instead, the interiors of black holes

seemed to contain

special areas deep inside called islands.

These islands

are part of the black holes,

but also not in a weird way.

They're both inside

and outside the black holes,

as if they are part

of the escaping radiation

that is depleting

the black holes over time.

And as they escape the information

within them. Escapes to

these new ideas

are pretty confounding,

even to physicists

who are discovering that

the cosmos and the nature of our reality

are even weirder

than we could have ever imagined.