You know what might be the best way
to travel to the other side of the world?
By drilling your way
right through the planet.
This would be the journey of a lifetime,
if you don't mind riding through
molten rock
and crushing pressure.
The heat is on, and you're under
all sorts of pressure.
Imagine going from Argentina to China
in less than an hour.
All you need is a hole
straight through the Earth.
But drilling this hole would be
the hardest part of the endeavor.
You could just handle it supervillain style,
and fire a giant laser at Earth.
But today, we'll be taking a trip
through the biggest hole we've drilled
in the history of our planet.
Sit tight because this
is going to be one heck of a ride.
The first thing you'd need to do would be
to drill the deepest hole
humanity has ever imagined.
We've already drilled holes
through the Earth on What If.
So you know what to do.
First, you'd need a really big drill.
And it would take a few years
to complete this project.
You'd be working in enormous
heat and pressure,
and it would increase the closer you
get to Earth's center.
But when the hole is finished,
you'd have your very own gravity tunnel,
a gateway between one side of the Earth
and the other.
I'll explain how it would work in a moment.
Next, you'd need to find yourself
a comfy vehicle
to get you through the Earth.
If you just jumped
into the depths of the Earth,
you'd get burned to a crisp
and crushed into a pancake.
So hop on the gravity train.
This train would accelerate
using only the force of gravity.
And it would protect you from the searing
heat and extreme pressure.
Depending on where you begin your trip,
the crust can be
5 to 70 km (3 to 43 mi) thick.
And amazingly,
You'd start your journey
feeling pretty carefree.
And at 20 m (67 ft) below the surface,
you'd be at the same level as subways
or the Paris Catacombs.
But let's go a little further down.
At 2.5 km (1.4 mi),
you'd be at the same depth
as the deepest fossil ever discovered.
And once you get to 3.6 km (2.2 mi),
you'd be able to see the devil worm.
It's the deepest living animal ever found.
Is it just me, or is it getting hot?
Believe it or not, some people
are working at this depth.
The Mponeng gold mine in South Africa
is so far down that the heat is an issue.
And believe me,
you wouldn't enjoy the 60 °C (140 °F)
temperature down here.
Then gravity would take you further down.
At 8.8 km (5.5 mi) below Earth's surface,
you'd have traveled further than the height
of Mount Everest.
And at 11 km (36,037 ft) underground,
you'd be deeper
than the Mariana Trench.
At 12.26 km (7.61 mi),
you would reach the same depth
as that Kola Superdeep Borehole.
It's the deepest hole we've ever dug.
And now you'd really feel
the intense pressure on your body.
As you approach the end of the first part
of this epic journey,
you might get to see a plethora of gems.
I'm talking about rubies, sapphires
and emeralds.
They could be valuable souvenirs
if you make it through
to the other side of the Earth.
And at 40 km (25 mi) down,
part one of your voyage
would be behind you.
Or above you,
depending on how you see it.
Most people think it has a lava-like texture.
But at this shallow depth,
relatively speaking, it's rock solid.
Only when you're deeper will it
start becoming molten.
This would be the longest
part of your journey.
The mantle is about
2,900 km (1,801 mi) thick.
You wouldn't see much inside it,
except for one dazzling exception.
At this depth,
the enormous pressure and heat
forms diamonds.
They make their way to the Earth's surface
through volcanic activity.
And that's where we humans find them.
But you are lucky
and find them at their birthplace.
Don't be shy, grab a few.
As you arrive about 410 km (255 mi)
below the surface,
things would start to get weird.
The mantle's rock would be molten hot.
But instead of staying in its melted state,
the mantle would turn hard.
That's because of the extreme pressure.
Moving on to the bottom of the mantle.
A mere 1,000 km (600 mi) down,
you would experience the force
of mantle blobs.
These are supercharged
plumes of hot rock.
And if they surfaced,
they would become devastating
supervolcanoes.
No need to say you'd feel extremely hot.
You'd be almost halfway through the Earth.
At depths of 3,000 km (1,864 mi),
the outer core is made of iron and nickel.
And boy, would it be hot.
At 5,000 km (2,107 mi) below the surface,
This giant solid iron sphere
And the pressure is a crushing
3.6 million times more than at sea level.
Let's hope your gravity train would be up
to challenge at these extreme
temperatures and pressures.
I didn't read the manual,
but I'm sure you'd be just fine.
Finally, you would make it
to the halfway point
of your subterranean voyage.
Right at the center of Earth,
the mass would be equal in all directions.
And you'd get to experience zero gravity.
But remember, that was just
half the journey.
You'll have to do all that again,
but in reverse to finish your trip.
This journey would put you under
a lot of pressure.
It would make you hot,
most likely uncomfortable
and rich.
You did collect all the diamonds,
didn't you?
Now, how long do you think it would take
to get from one side of Earth to the other?
OK, it's time I told you more
about the gravity tunnel.
This is a theoretical passageway
through the Earth.
Or simply a hole through the Earth,
as I like to call it.
If it's created correctly,
you could get from one side of the Earth
to the other
in about 42 minutes
using a gravity train.
But as I mentioned before,
traveling through Earth
would be the easy part.
It's the drilling that would be hard.
If we could engineer such a feat,
it would revolutionize travel.
And you would have one short,
but epic journey.
But what if that hole
through Earth was bigger?
What if Earth were shaped like a donut?
As always, I'll leave that story
for another WHAT IF.