Wormhole scientists are absolutely buzzing.
So what's going on?
Sci-fi writers have always loved wormholes.
They're a convenient way to whizz a character
through space at impossible speeds.
But for years, scientists didn't really
take much interest in them.
Luckily, there has been a recent boom
in wormhole research.
So what's happening?
Could we one day travel through a wormhole?
And what would happen if we did?
Let's explore the unexplored.
Let's start with what a wormhole actually is.
You've probably got an image like this
in your mind.
A tunnel or a bridge.
And that's exactly what it is.
A bridge between two parts of the universe.
One way of thinking about a wormhole
is almost like two black holes, back to back.
The black holes warp the fabric of spacetime
so much that it completely bends back in on itself,
and the openings can allow you to pass
straight through from one point to another.
To understand how these sci-fi-like wormholes
might work, we first need to understand
the traditional idea of a wormhole.
One that's equally as interesting,
but perhaps a little less useful for space travel,
a non-traversable wormhole.
To help explain that is theoretical physicist
Juan Maldacena, one of the pioneering experts
in wormholes who's actively researching some
very exciting, albeit mind-boggling, science.
So a non-traversable wormhole, it's a bit like
this picture of the tunnel.
And so, with the exception that it's a tunnel
that is present at one moment in time
and then at later times
it stretches and becomes thinner,
and eventually it collapses completely
and it stretches almost infinitely.
And so if you try to traverse this tunnel,
you would go into the tunnel and the tunnel closes
before you can exit on the other side.
So that's why it's called non-traversable.
And this closing of the tunnel is similar to,
well, it's the same actually as the singularity
you have in the interior of black holes.
And so if you try to go through this tunnel,
you would die.
So it's not recommendable.
It's not recommended.
Right, so this doesn't seem like
the most practical wormhole in the world.
There would have been a lot of very short sci-fi films
if the leading character just hopped into one
and immediately died.
On the other hand, you could binge watch
all of Doctor Who in about five minutes.
So how could we make one that we could
actually travel through?
The previous thinking was that wormholes
would immediately collapse
because they're so inherently unstable.
What was missing was some sort of matter
that would prop the wormhole open long enough
to travel through.
And this is where it gets interesting.
To have a wormhole that can be held open
and be traversable, just as a theoretical question
of whether it is possible with the matter we know,
it is possible,
but only when they are very small.
Now you can also ask the question of whether
if we- could we discover some other type of matter
so that we could have a very big wormhole
that we as a person could go through?
And the answer to that is yes.
So we could have some very, some new form
of matter that hasn't been discovered.
It's very unlikely that this form of matter
should exist. That should, put that
from the very beginning.
But it is theoretically possible
to have that kind of matter,
and they would have to be-
their mouths have to be very big
so that they wouldn't kill the traveller.
Because if a person goes through a region
where the curvature of space is relatively large,
you would be pulled.
Your head is pulled from your toes and you would die.
So you have to make sure that
the curvature of spacetime is weak enough.
And for that, you need that the mass of the wormhole
should be as big as the size of the Earth.
So very big, much bigger than ourselves.
Keeping up?
Right, so there's the traditional wormholes,
the non-traversable ones that as soon as
you enter, they collapse.
Bad idea.
So what do you do when something collapses?
You prop it open with something.
Good idea.
And what do you prop it open with?
Wood, scaffold, a force field?
No, a weird type of matter that opposes
the force of gravity that stops the wormhole
from collapsing.
We don't know if it exists,
but it theoretically could.
It doesn't defy the laws of physics.
Simple.
Well, there's more.
And then with this type of matter,
you could have a wormhole,
but it would take a long time to go through it,
as seen from the outside.
So you could have one here and one
on the other side of the galaxy, let's say,
or something far away.
And then you could go through the wormhole.
It would take you,
let's say, 20,000 years.
And that is the time for
someone that remains outside.
But for the traveller, it could take
a very short time, like a second.
You would just go through it
and you start travelling very, very fast.
And because you travel very fast,
your clock runs much more slowly.
And for you, it looks like it was just one second.
So in theory, we need a new type of matter
that we don't know exists, yet,
to have anti-matter properties that allow it
to prop open a wormhole,
a wormhole the size of the Earth.
And if we make it through without any particles
tearing through us and avoid having
our bodies stretched and our heads pulled off,
if all of that happens and we make it
to the other end...
everyone you know would be dead.
Great.
Look, needless to say,
this is all theoretical,
but it is based in real physics
and it's incredibly exciting.
There's a big buzz around wormhole science
at the moment,
which is usually some sort of side area of research.
And this is down to some new breakthrough discoveries.
Scientists have finally proven that entering
a black hole is not necessarily a one-way trip.
While this probably won't help with the issue of
travelling through a wormhole,
it does stop the laws of quantum mechanics
from breaking,
which is a big relief to a lot of people.
There's a development that has happened
in the last couple of years where people
have realised that- this- something similar
to wormholes is responsible for
getting the information out of black holes.
So there was this famous information problem
for black holes that you can send information
to a black hole and the black hole will emit
Hawking radiation that apparently has no information.
But it seems that the wormholes managed to get
this information out of the black hole.
So, yeah, that's, I think, the most exciting development
of the last few years.
So previously, people thought that anything
entering a black hole couldn't leave it.
This was known as the 'black hole information paradox'.
Even though black holes emit radiation,
Stephen Hawking suggested that this radiation
didn't contain any of the information
pertaining to what went into the black hole.
I discovered that black holes are
not that black after all.
They give off what has been called Hawking radiation.
Because of this emission, black holes will
lose mass and eventually evaporate completely.
The Hawking radiation seemed to be random
and featureless,
so it appeared that all the information about
what fell in the black hole was lost.
However, new studies suggest otherwise,
that in fact, you can decode information
coming out of a black hole and it's not lost forever.
So wormholes could exist,
and they're far more weird and complex
than movies would allow you to believe.
OK, they're far less practical.
But when has practical ever been fun?
So if you're ever hurtling through outer space,
headed towards the barrel of a wormhole
and you previously would have thought about going in,
you'll be pretty glad you've seen this video.