of the world, it's a hike. About 20,000 kilometers.

的，是一次徒步旅行。約2萬公里。

But what if you didn't have to travel across the surface?

但如果你不用穿越地表呢？

What if you could dig straight through to the other side?

如果你能直接挖到另一邊呢？

If you're trying to dig to China from the US,

如果你想從美國挖到中國。

there's something you should know first.

有一些東西你應該先知道。

The opposite point on the planet isn't in China.

地球上的對面點不在中國。

It's somewhere in the middle of the Indian Ocean.

它在印度洋中間的某個地方。

So, to get to China,

所以，要到中國。

you should start digging in either Argentina or Chile.

你應該從阿根廷或智利開始挖掘。

Your first challenge would be

你的第一個挑戰是

digging through the Earth's crust.

挖穿地殼。

It's the thinnest of Earth's three main layers,

它是地球三大層中最薄的一層。

yet humans have never drilled all the way through it.

但人類卻從未將其全部鑽透。

As you descend, you'd soon reach the depth

隨著你的下沉，你很快就會到了深處

of the Paris Catacombs, the deepest metro station,

的巴黎地下墓穴，最深的地鐵站。

and the devil worm,

和魔鬼蟲。

the deepest animal we've ever discovered underground.

是我們在地下發現的最深的動物。

Then, it would start to get hot.

然後，就會開始發熱。

At 4,000 meters down, you'd pass the deepest mine

在4000米的深處，你會經過最深的礦井。

on the planet, which is cooled with ice

在這個星球上，它是用冰冷卻的

to make workers comfortable, because, down here,

要讓工人們舒服，因為，在這下面。

temperatures are 60 degrees Celsius.

溫度為60攝氏度。

By 8,800 meters, you'll be as deep as Mt. Everest is tall,

到了8800米，你會像珠穆朗瑪峰一樣高深莫測。

but it's still not the deepest point humans have ever dug.

但這仍然不是人類所挖的最深的點。

That point is at the bottom of the Kola Superdeep Borehole,

這個點就在科拉超深孔的底部。

at 12,260 meters below the surface.

在地表下12260米處。

Down here, there's 4,000 times more pressure

在這裡，有4000倍的壓力。

than at sea level,

比在海平面上。

and temperatures push 180 degrees Celsius,

和溫度推到180攝氏度。

so you'd need a lot of insulation

所以你需要大量的絕緣材料

to carry on and keep from melting.

來進行和保持不融化。

At around 40,000 meters, you'd reach Earth's second

在大約4萬米的地方，你會到達地球的第二座山。

and largest layer, the mantle,

和最大的一層，即地幔。

which makes up a whopping 84% of the planet's volume.

佔了地球體積的84%。

Near the border,

靠近邊境。

temperatures climb to around 1,000 degrees Celsius,

溫度攀升到1000攝氏度左右。

hot enough to melt many metals,

熱度足以熔化許多金屬。

like silver, but not a steel drill.

像銀子，但不是鋼鑽。

And good thing because you'll need it

這是件好事，因為你會需要它

to drill through the first part of the mantle,

以鑽透地幔的第一部分。

which is made of solid rock,

是由堅固的岩石構成的。

until you reach 100,000 meters, that is,

直到你達到10萬米，也就是。

when you might need to switch to a propeller.

當你可能需要換成螺旋槳的時候。

Here, the pressure and temperature are so high that,

在這裡，壓力和溫度都很高，所以。

in some places, rock takes on a caramel-like consistency.

在某些地方，岩石會呈現出焦糖般的稠度。

In fact, it's this rock that ultimately erupts

事實上，最終爆發的就是這塊石頭。

from volcanoes on the surface.

從地表的火山。

At 150,000 meters, keep your eyes peeled for diamonds.

在15萬米高空，要睜大眼睛尋找鑽石。

They form when heat

它們在受熱時形成

and pressure restructure the carbon atoms in this region.

和壓力重組這個區域的碳原子。

Once you reach 410,000 meters, the rock is solid again,

到了41萬米，岩石又變得堅實起來。

so it's back to the drill.

所以它的回鑽。

You see, while it's still plenty hot

你看，趁著天氣還很熱的時候

at this depth to melt rock,

在這個深度融化岩石。

the pressure is so extreme that the molecules

壓力極大，以至於分子之間

inside literally can't move into a liquid state.

裡面的字面意思是不能移動到液體狀態。

Then, by 3 million meters down,

然後，由300萬米下。

you'd reach Earth's third layer, the outer core.

你會到達地球的第三層，外核。

Unlike Earth's crust and mantle,

與地殼和地幔不同。

the core is made of iron and nickel.

核心是由鐵和鎳製成的。

Temperatures here are the same as the surface of the sun,

這裡的溫度和太陽表面的溫度是一樣的。

hot enough to melt all that metal,

熱得足以融化所有的金屬。

so, yep, back to the propeller.

所以，是的，回到螺旋槳。

And it would have to be made

而且必須要做

out of some kind of supermaterial,

由某種超材料製成。

because no known element has a melting point

因為沒有任何已知元素有熔點

above 6,000 degrees Celsius.

6,000攝氏度以上。

Making matters worse, the outer core also has low gravity,

更糟糕的是，外核的重力也很低。

because, when you're that deep,

因為，當你深陷其中，

much of the planet's mass is now above you,

地球的大部分品質現在都在你之上。

which produces a gravitational force

它產生的引力

that pulls away from the center.

，拉開了中心。

So to continue,

所以要繼續。

you'd need a super heat- and pressure-proof submarine

你需要一個超耐熱、超耐壓的潛水艇。

that moves like rockets in space

飄忽不定

by shooting fuel out the back end.

通過將燃料射出後端。

You'd soon arrive at the inner core,

你很快就會到達內核。

around 5 million meters below the surface.

在地表下500萬米左右。

The inner core is one giant sphere of solid iron,

內核是一個巨大的實心鐵球。

so it would definitely be challenging to get through.

所以要想通過，肯定是有難度的。

But if you did find a way,

但如果你真的找到了辦法。

you'd soon hit the halfway point,

你很快就會達到半途而廢的地步。

about 6.4 million meters down,

下約640萬米。

also known as the center of the Earth.

又稱地球中心。

Now, there's nearly the same amount of mass all around you,

現在，你的周圍幾乎有相同數量的品質。

pulling you equally in all directions,

將你平等地拉向各個方向。

so there's zero gravity here.

所以這裡是零重力的。

And now is when the trip really gets hard. The second half.

而現在是旅行真正變得艱難的時候。下半場

Because as you dig past the inner core,

因為當你挖過內核的時候。

you'd soon feel the pull of gravity again.

你很快就會再次感受到地心引力的作用。

And this time, it'd be pulling you from above,

而這一次，它會從上面拉著你。

where the majority of Earth's mass is now.

現在地球的大部分品質都在那裡。

So while you might be digging down,

所以，當你可能會被挖下去。

relative to where you started,

相對於你開始的地方。

it'll feel like you're climbing up.

就像你在往上爬。

And if you didn't have those handy rockets propelling you,

如果你沒有那些方便的火箭推動你。

you'd fall right back to the core.

你會跌回核心。

But 6.4 million meters later,

但640萬米後。

after powering through impenetrable iron,

在力透紙背的鐵器後。

molten alloy, and solid and mushy rock,

熔融的合金，和固體和粘稠的岩石。

you'd arrive, at long last, on the other side, in China.

你終於到達了，在另一邊，在中國。

That would certainly come as a relief,

那當然是一種解脫。

but it wouldn't even be the best part.

但它甚至不會是最好的部分。

Assuming you left a tunnel through the center of the Earth

假設你在地球中心留下了一條隧道。

behind you, you'd now be able to travel back and forth

後面，你就可以來回走動了

between China and Argentina in under an hour,

在中國和阿根廷之間，不到一個小時。

simply by jumping in.

只要跳進去就可以了。

To learn why, check out another video we made

要了解原因，請查看我們製作的另一個視頻。

about jumping through the center of the Earth.

關於跳過地球中心。