Name: 如果蓋一座十億層樓高的大樓會發生什麼事？ (What if you built a billion-story building?)
Uploaded: 2025-06-18T21:01:30.000Z
Duration: 3 min 56 s

關係子句

This question came from Keira, who at age four and a half, wanted to build a billion-story building.

這個問題來自 Keira，一位四歲半的小朋友，她想建造一棟擁有十億層樓的建築物。

Actually, it came from Keira's dad, who wanted to help Keira appreciate how big and difficult such a project would be.

實際上，是 Keira 的爸爸提的，他想幫助 Keira 了解這樣的工程有多巨大、多困難。

Keira, if you make a building too tall, the top part is heavy and it squishes the bottom part, until you make it really tall, and then the top part will tear itself off and go into orbit near the moon.

Keira，如果你把建築物蓋得太高，上面的部分會太重，壓扁底部；如果你蓋得「非常非常」高，上面的部分甚至會扯裂建築物並脫離地球，進入接近月球的軌道。

Have you ever tried to make a tower out of Jell-O?

It's easy to make a little tiny wobbly Jell-O castle, in fact, some people like to serve fancy Jell-O that way.

做一個小小的、搖搖晃晃的果凍城堡很容易，其實有些人會把果凍這樣當成精緻甜點。

But if you try to make a really big Jell-O castle, the whole thing smushes down on itself.

但如果你試著做一個很大的果凍城堡，整座城堡就會被自己壓扁。

The same thing happens with buildings, eventually.

建築物也會發生同樣的情況，只是比較慢。

The tallest are almost a kilometer tall, and we could probably make buildings two or even three kilometers tall if we wanted,

最高的建築物接近一公里高，如果想要，我們大概能蓋到兩公里甚至三公里高。

and they would still be able to stand up under their own weight.

而且它們依然能承受自己的重量。

But too much higher and we'd run into the Jell-O problem, the top part would squish the bottom part.

但如果再高，就會遇上「果凍問題」──上面的部分會把下面壓垮。

There are other problems with tall buildings, too.

The wind up high is very strong and buildings have to be very strong to stand up against the wind.

高空的風非常強，建築物必須非常堅固才能抵擋。

Another problem is, surprisingly, elevators.

另一個問題──很意外地──是電梯。

Tall buildings need elevators, since no one wants to climb hundreds of flights of stairs.

高樓需要電梯，因為沒有人願意爬幾百層樓梯。

If your building has lots of floors, you need lots of different elevators to get all the people where they're trying to go at once.

如果你的建築有很多樓層，就需要很多不同的電梯讓大家能同時到達目的地。

Some of our existing tall buildings have floors purely dedicated to letting people change from one elevator to another.

現在有些超高層建築甚至有整層樓專門用來讓人換電梯。

A building several miles tall would cost many billions of dollars, and most people don't think giant towers a few miles tall are important enough to spend billions of dollars on.

一棟高達好幾英里的建築物會花掉數十億美元，而大部分人不認為蓋幾英里高的巨塔值得花這麼多錢。

Even if you found a lot of money, you'd still have problems making a tower a billion stories tall.

即使你有很多錢，你仍然無法真的蓋出一棟十億層的大樓。

A big skyscraper might have about 100 floors, which means it's as tall as 100 little houses.

一棟大型摩天大樓大概有 100 層，也就是約等於 100 間小房子的高度。

If you stacked 100 skyscrapers on each other to make a mega skyscraper, it would reach halfway to space.

如果你把 100 棟摩天大樓堆在一起，它會高達半個太空的距離。

This skyscraper would still only have 10,000 floors, which is way less than your billion floors.

但這棟「超級摩天大樓」只有 10,000 層，仍然比你的十億層少非常多。

So let's stack 100 mega skyscrapers to make a mega-mega skyscraper.

所以我們再把 100 棟超級摩天大樓堆起來，做成「超級超級摩天大樓」。

The mega-mega skyscraper would stick out so far from Earth that spacecraft would crash into it,

這棟「超級超級摩天大樓」會高到太空船會撞上它。

some, like the International Space Station, could steer around it.

有些飛行器，例如國際太空站，可以閃過它。

But space is full of broken satellites and pieces of junk all flying around at random,

但太空中充滿壞掉的衛星與碎片，它們四處亂飛，

some of which will eventually smash into your mega-mega skyscraper at very high speeds.

其中一些最終會以極高速度撞上你的超級超級摩天大樓。

And anyway, a mega-mega skyscraper is only a million floors high, that's still a lot smaller than the billion that you want.

而且，超級超級摩天大樓也只有一百萬層，仍然遠小於十億層。

So let's stack up 100 mega-mega-skyscrapers to make a mega-mega-mega-skyscraper.

所以我們再把 100 棟超級超級摩天大樓堆起來，做成「超級超級超級摩天大樓」。

The mega-mega-mega-skyscraper would be so tall that the top   would just barely brush against the Moon.

這棟「超級超級超級摩天大樓」會高到頂端會輕輕擦過月球。

And it would introduce a new problem - centrifugal forces.

但這會帶來一個新問題──離心力。

Just like how a swing carousel throws you outward, anything spinning in sync with Earth's equator is thrown outward.

就像旋轉鞦韆會把你往外甩，任何在地球赤道同步旋轉的東西都會被向外甩。

On the surface, objects literally weigh about half a percent less at the Earth's equator than at the poles.

在地球表面，赤道上的物體重量比在南北極輕大約 0.5%。

The farther out you go, the weaker Earth's gravity gets and the stronger the centrifugal force is.

你越往外走，地球重力越弱，而離心力越強。

The effects are equal at just over a tenth of the way to the moon.

在距離月球約十分之一位置時，兩者剛好一樣大。

If you build a skyscraper this tall, you could launch a geostationary satellite just by letting go of it out the window.

如果你蓋一棟這麼高的摩天大樓，你只要把衛星從窗口放手，它就能飛到地球同步軌道。

But our mega mega mega skyscraper is so much taller than geostationary orbit that most of its mass is where the outward pulling centrifugal force is much, much stronger than gravity.

但我們的「超級超級超級摩天大樓」比同步軌道還高很多，大部分質量都在重力比離心力弱很多的地方。

The engineering challenge of this skyscraper isn't that it'll collapse down on itself like Jell-O,

這棟大樓的工程問題不是像果凍那樣被壓垮，

but that it'll tear itself up by the roots and go into orbit near the moon.

而是它會從根部被撕裂，然後飛到月球附近的軌道。

And it still wouldn't be a billion stories.

To get there, we'd have to stack 10 mega mega mega skyscrapers on top of each other to make one Keira skyscraper.

要達到十億層，我們需要把 10 棟超級超級超級摩天大樓堆起來，變成一棟 Keira 摩天大樓。

At the top, the Keira skyscraper would be going faster than the speed with which the solar system orbits the Milky Way.

在頂端，這棟 Keira 摩天大樓的速度會比太陽系繞銀河系的速度還快。

And if you timed things right, you could launch a satellite with almost enough velocity to leave our galaxy just by letting go of it out your window.

如果算準時間，你甚至能從窗戶放手，把一顆衛星丟出去，接近逃離銀河系的速度。

Suffice it to say that Keira's skyscraper would be pretty close to impossible to build, and any loose pieces would fly off and get strewn throughout the galaxy.

簡單來說，Keira 想像的這棟大樓幾乎完全不可能建造，而且任何鬆脫的零件都會被甩向整個銀河。

But the view from the roof would be incredible.

但從頂樓看出去的風景一定會美得令人難以想像。