你應該吃掉自己嗎？：英語精讀講義

Hey, Vsauce.

嘿，Vsauce。

Michael here.

我是 Michael。

And Jake.

還有 Jake。

And Kevin.

還有 Kevin。

And we are in Santa Monica,

我們現在在聖塔莫尼卡，

which of course means that the V in Vsauce will stand for the Roman numeral five, 講解

這當然表示，Vsauce 裡的 V 要代表羅馬數字 5，

as in five questions from you guys.

也就是回答你們提出的五個問題。

Our first question comes from Notch.

第一個問題來自 Notch。

He didn't ask this of me in particular,

他其實不是特別問我的，

but I love how non-intuitive the answer is. 用詞

但我很喜歡這個反直覺的答案。

Assume an Earth that's perfectly spherical and a rope stretched around the equator snugly. 文法

假設地球是個完美的球體，一條繩子緊貼赤道繞了一圈。

What would happen if that rope was just, 文法

如果這條繩子只是，

say, 6 m longer? 語氣意圖

比方說，變長了 6 公尺，會怎麼樣？

6 m isn't very much,

6 公尺並不算多，

but because of the relationship between a circumference and a radius,

但由於圓周長和半徑之間的關係，

6 m of extra rope would allow the entire rope to not fit snugly around the Earth,

多出來的 6 公尺會讓整條繩子不再緊貼地球，

but 1 m above it all the way around.

而是整圈都懸在地表上方 1 公尺處。

That's cool,

這很酷，

but what if instead of a rope we used something more rigid like a structure, 文法

但如果我們不用繩子，而改用更堅硬的東西，比如某種結構，

a bridge,

一座橋，

and we built the bridge all the way around the Earth,

並讓它完整環繞地球一圈，

and then all at once destroyed its supports? 片語搭配

接著同時摧毀所有支撐，會怎麼樣？

Would it float?

它會浮在空中嗎？

Clearly the Earth's gravity would pull the structure down,

地球引力顯然會把這座結構往下拉，

but down is in the opposite direction for the other side of the bridge. 片語搭配

但對橋的另一側來說，「下」卻是相反的方向。

Well, it turns out such a scenario would be incredibly unstable. 表達脈絡

其實，這種狀況會極不穩定。

Earth's gravity isn't equal everywhere,

地球各處的引力並不相同，

and if you follow at Tweetsauce,

如果你有追蹤 Tweetsauce，

you saw some great graphs showing just how much gravity changes 文法

就看過一些很棒的圖表，顯示引力的變化究竟有多大，

simply based on the density of rock below.

而這光是由下方岩石的密度所造成。

When you factor in the Sun and the Moon, 片語動詞

再把太陽和月球的影響算進去，

you wind up with a bridge structure that is not going to stay where it is. 片語動詞

最後這座橋根本不可能待在原位。

If the bridge itself was indestructible,

如果橋本身堅不可摧，

it would start violently hula hooping around the Earth, 慣用語

它就會像呼拉圈一樣開始繞著地球猛烈晃動，

crushing things.

一路輾碎各種東西。

But there's no known material strong enough to do that.

但目前沒有任何已知材料堅固到足以做到這一點。

Instead,

反而，

you would wind up with bridge pieces flying everywhere.

最後只會有橋梁碎片到處亂飛。

A sphere around the Earth would be a bit more stable,

包圍地球的球殼會稍微穩定一點，

but a ring, not so much.

但圓環就沒那麼穩定了。

The ring,

這個圓環，

even if spinning,

就算持續旋轉，

would rapidly break apart into smaller pieces. 片語動詞

也會迅速碎裂成更小的碎片。

Last week you guys asked me a question that I have always wondered.

上週，你們問了我一個我一直也很好奇的問題。

Let's say I was stranded in the mountains waiting for rescuers to arrive, 表達脈絡

假設我受困在山裡，等著救難人員趕來，

but it was going to take a while.

但他們還要一段時間才會到。

I had plenty of snow,

我身邊有大量積雪，

and plenty of water,

也有充足的水，

but I was hungry,

可是我很餓，

dying of starvation.

正在活活餓死。

Would it make sense 片語搭配

那麼，

to amputate one of my legs and eat it?

截掉自己的一條腿並吃掉它，會不會比較划算？

I mean,

我的意思是，

it kind of makes sense, 語氣意圖

這好像有點道理，

right?

對吧？

I'd have my entire leg to eat as food,

我可以把整條腿當成食物，

which would probably fill me up, 片語動詞

大概能填飽肚子，

and I would have one less limb that I would need to keep alive.

而且少了一條需要維持生命的肢體。

The only problem is that the trauma your body would endure

唯一的問題是，你的身體所承受的創傷

from the loss of a limb

——也就是失去一條肢體所造成的創傷——

would greatly exceed the benefit you would get by eating the food.

會遠遠超過吃掉它能獲得的好處。

You're better off keeping that limb on your body 文法

你最好還是把那條腿留在身上，

because your body's process of using reserves of energy

因為身體動用能量儲備的過程

is more efficient than the process of digestion.

比消化過程更有效率。

So, keep the leg on and let it wither away, 片語動詞

所以，留著這條腿，讓它慢慢萎縮，

keeping you alive.

藉此維持你的生命。

Don't cut it off and eat it and digest it. 片語動詞

別把它砍下來吃掉，再費力消化它。

How does hair know when to stop growing?

頭髮怎麼知道何時該停止生長？

It's a good question because the hair on my arm,

這是個好問題，因為我手臂上的毛，

which there's a lot of,

而且還不少，

never grows any longer than this.

從來不會長得比現在更長。

And if I were to shave my arm off,

如果我把手臂上的毛剃掉，

it would grow back and stop right where it is right now. 片語動詞

它還會重新長出來，然後在現在這個長度停下。

But head hair is different.

但頭髮不一樣。

For instance, my hair,

比如我的頭髮，

what's left of it, 語氣意圖

或者說，還剩下的那些，

would keep growing if I didn't cut it.

如果我不剪，就會繼續長下去。

But no other animal has that situation.

可是其他動物都不會這樣。

You don't see wolves out in the forest saying,

你不會看到森林裡的狼說：

"Wow, look how long my hair is getting.

「哇，瞧我的毛長得這麼長了。

I better get to the barber shop." 文法

我最好趕快去一趟理髮店。」

So, why do humans have head hair that grows so long,

那麼，為什麼人類的頭髮能長得那麼長，

but body hair elsewhere that stops seemingly right when it's supposed to?

而身體其他部位的毛卻彷彿總能恰到好處地停止生長？

Well, first things first, 慣用語

首先，

the hair on your head will not keep growing forever.

你的頭髮並不會永遠長下去。

Typically around 6 years of growth is the limit.

通常，生長期的上限是 6 年左右。

When hair grows,

毛髮生長時，

it is in what is known as its anagen phase. 片語搭配

會處於所謂的生長期。

And for hair on your head,

對頭髮而言，

that phase can last up to 6 years.

這個階段最長可持續 6 年。

But the anagen phase of hair elsewhere on your body,

但身體其他部位毛髮的生長期，

eyebrows,

比如眉毛，

eyelashes,

睫毛，

is much shorter,

就短得多，

except in cases like this guy,

不過也有像這位老兄這樣的例外，

whose eyebrows grow like head hair and have allowed him to set the world record for longest eyebrows. 片語搭配

他的眉毛會像頭髮一樣生長，讓他創下了全世界最長眉毛的紀錄。

Humans probably lost their fur coats,

人類很可能褪去了那身「毛皮大衣」，

their thick body hair,

也就是濃密的體毛，

because it didn't really help us hunting and running around sweating on the savanna.

因為我們在疏林草原上狩獵、奔跑和流汗時，它其實沒什麼幫助。

And unlike other animals,

而且和其他動物不同，

us humans had discovered fire and could make clothing to keep ourselves warm without needing a built-in fur coat. 慣用語

我們人類發現了火，也能製作衣物保暖，不需要自帶一件毛皮大衣。

To be sure, 表達脈絡

當然，

long hair that falls over your ears and neck can keep you warmer,

垂在耳朵和脖子上的長髮確實能讓你更暖和，

but leading theories also argue that long head hair may be our fault, 表達脈絡

但主流理論也認為，頭髮這麼長或許是我們自己造成的，

a result of the fact that early humans picked mates that could grow longer hair on their heads. 用詞

因為早期人類會選擇頭髮能長得更長的對象交配。

Mates that could do that were probably healthier,

能做到這一點的伴侶可能更健康，

and in colder climates,

而且在較寒冷的氣候裡，

literally had a built-in hat to keep their body warm.

他們其實還自帶一頂能為身體保暖的帽子。

One of the questions I get the most is about eye floaters, 用詞

我最常收到的問題之一，是關於眼睛裡的飛蚊，

those little dots or squiggles that you see in your vision,

也就是視野中出現的那些小點或彎彎曲曲的細線，

especially when looking at a bland scene like the clear blue sky.

特別是看著晴朗藍天這類單調背景時。

Eye floaters are made out of little fibrils that occur in your eye as you age. 片語動詞

飛蚊是眼睛隨年齡增長而產生的微小纖維。

And you can't look directly at them because they're inside the fluid of your eye.

你無法直接盯著它們看，因為它們就在眼內的液體中。

Turning your eye to look at them simply causes the fluid to move and the floater as well. 文法

轉動眼球去看，只會讓眼內液體跟著移動，飛蚊也會一起移動。

But the thing about eye floater that I love the most is that they are almost always microscopic.

但我最喜歡飛蚊的一點是，它們幾乎總是小到只能用顯微鏡看見。

You can't see them with the naked eye 慣用語

你用肉眼看不到它們，

except when they are inside your eye.

除非它們就在你的眼睛裡。

If you were to pull an eye floater out, 文法

如果把一條飛蚊從眼睛裡取出來，

you wouldn't be able to see it.

你反而看不見它。

But in your eye,

可是在眼睛裡，

it's close enough to the retina 文法

它離視網膜夠近，

to leave a shadow on the retina,

能在視網膜上投下影子，

and that's what you see when you see eye floaters.

而你看到飛蚊時，看到的正是這個影子。

Finally,

最後，

how much would Wikipedia weigh if I printed all the text out and bound it into books? 講解

如果我把 Wikipedia 上的所有文字都印出來並裝訂成書，會有多重？

Well, luckily,

幸好，

there's a Wikipedia article about this very topic. 用詞

Wikipedia 上正好有一篇條目專門討論這個主題。

The English language Wikipedia contains about 2,345 million words,

英文版 Wikipedia 大約包含 23.45 億個英文單字，

which, 文法

如果

if printed at the density of the Encyclopedia Britannica,

按照《大英百科全書》的文字密度印刷，

would equal about 1,759 volumes,

就相當於大約 1,759 冊，

which would look like this.

看起來會像這樣。

Altogether,

全部加起來，

they would weigh about 7,000 lb.

大約重 7,000 磅。

If you're between the ages of 13 and 18, 片語搭配

如果你的年齡介於 13 到 18 歲，

you may want to check out the Google Science Fair. 語氣意圖

不妨去看看 Google Science Fair。

It's an amazing competition.

這是一項很精彩的競賽。

These guys are great.

這些人真的很厲害。

They actually helped make that Earth Bridge animation for me.

他們還幫我製作了剛才那段「地球橋梁」動畫。

So, be sure to check out googlesciencefair.com.

所以，記得去 googlesciencefair.com 看看。

And I'll keep checking out Los Angeles.

我也會繼續逛逛洛杉磯。

I'm here with Kevin and Jake from Vsauce 2 and 3 for the first time ever. 片語搭配

這是我第一次和 Vsauce 2、Vsauce 3 的 Kevin 與 Jake 聚在一起。

The three of us have never been in one location simultaneously until now. 文法

我們三個以前從未同時出現在同一個地方，直到現在。

So, be sure you're subscribed to us because amazing videos will come soon.

所以一定要訂閱我們的頻道，因為精彩影片很快就會推出。

And as always, thanks for watching.

一如往常，感謝收看。