你应该吃掉自己吗？：英语精读讲义

Hey, Vsauce.

嘿，Vsauce。

Michael here.

我是 Michael。

And Jake.

还有 Jake。

And Kevin.

还有 Kevin。

And we are in Santa Monica,

我们现在在圣莫尼卡，

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

这当然意味着，Vsauce 里的 V 要代表罗马数字 5，

as in five questions from you guys.

也就是回答你们提出的五个问题。

Our first question comes from Notch.

第一个问题来自 Notch。

He didn't ask this of me in particular,

他其实不是专门问我的，

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

但我很喜欢这个反直觉的答案。

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

假设地球是个完美球体，一根绳子紧贴着赤道绕了一圈。

What would happen if that rope was just, 語法

如果这根绳子只是，

say, 6 m longer? 語氣意圖

比如说，长了 6 米，会怎么样？

6 m isn't very much,

6 米并不算多，

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

但由于圆周长和半径之间的关系，

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

多出来的 6 米会让整根绳子不再紧贴地球，

but 1 m above it all the way around.

而是整圈都悬在地表上方 1 米处。

That's cool,

这很酷，

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

但如果我们不用绳子，而换成更坚硬的东西，比如某种结构，

a bridge,

一座桥，

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

并让它绕地球整整一圈，

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

然后同时摧毁所有支撑，会怎么样？

Would it float?

它会悬浮吗？

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

地球引力显然会把这座结构往下拉，

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

可对于桥的另一边来说，“下”却是相反的方向。

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

其实，这种情况会极其不稳定。

Earth's gravity isn't equal everywhere,

地球各处的引力并不相同，

and if you follow at Tweetsauce,

如果你关注了 Tweetsauce，

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

就会看到一些很棒的图表，显示引力变化究竟有多大，

simply based on the density of rock below.

而这仅仅取决于下方岩石的密度。

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

再把太阳和月球的影响考虑进去，

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

最终这座桥根本不可能待在原位。

If the bridge itself was indestructible,

如果桥本身坚不可摧，

it would start violently hula hooping around the Earth, 習語

它就会像呼啦圈一样开始围着地球猛烈晃动，

crushing things.

一路碾碎各种东西。

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

但目前没有任何已知材料坚固到足以做到这一点。

Instead,

反而，

you would wind up with bridge pieces flying everywhere.

最后只会有桥的碎片四处乱飞。

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

包围地球的球壳会稍微稳定一点，

but a ring, not so much.

但圆环就没那么稳定了。

The ring,

这个圆环，

even if spinning,

即使在旋转，

would rapidly break apart into smaller pieces. 短語動詞

也会迅速解体成更小的碎片。

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

上周，你们问了我一个我一直也很好奇的问题。

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

假设我被困在山里，等着救援人员赶来，

but it was going to take a while.

但他们还要过一阵子才能到。

I had plenty of snow,

我身边有大量积雪，

and plenty of water,

也有充足的水，

but I was hungry,

可我很饿，

dying of starvation.

正在活活饿死。

Would it make sense 短語搭配

那么，

to amputate one of my legs and eat it?

截掉自己的一条腿并把它吃掉，是否划算？

I mean,

我的意思是，

it kind of makes sense, 語氣意圖

这好像有点道理，

right?

对吧？

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

我可以把整条腿当成食物，

which would probably fill me up, 短語動詞

大概能填饱肚子，

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

而且少了一条需要维持生命的肢体。

The only problem is that the trauma your body would endure

唯一的问题是，你的身体所承受的创伤

from the loss of a limb

——也就是失去一条肢体造成的创伤——

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

会远远超过吃掉它所带来的好处。

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

你最好还是把那条腿留在身上，

because your body's process of using reserves of energy

因为身体动用能量储备的过程

is more efficient than the process of digestion.

比消化过程更高效。

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

所以，留着这条腿，让它慢慢消瘦，

keeping you alive.

以此维持你的生命。

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

别把它砍下来吃掉，再费力消化它。

How does hair know when to stop growing?

头发怎么知道什么时候该停止生长？

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

这是个好问题，因为我手臂上的毛，

which there's a lot of,

而且还不少，

never grows any longer than this.

从来不会长得比现在更长。

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. 短語動詞

它还会重新长出来，然后在现在这个长度停下。

But head hair is different.

但头发不一样。

For instance, my hair,

比如我的头发，

what's left of it, 語氣意圖

或者说，还剩下的那些，

would keep growing if I didn't cut it.

如果我不剪，就会一直长下去。

But no other animal has that situation.

可其他动物都不会这样。

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

你不会看到森林里的狼说：

"Wow, look how long my hair is getting.

“哇，瞧我的毛长得这么长了。

I better get to the barber shop." 語法

我最好赶紧去趟理发店。”

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

那么，为什么人类的头发能长得那么长，

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

而身体其他部位的毛却仿佛总能恰到好处地停止生长？

Well, first things first, 習語

首先，

the hair on your head will not keep growing forever.

你的头发并不会永远长下去。

Typically around 6 years of growth is the limit.

通常，生长期的上限是 6 年左右。

When hair grows,

毛发在生长时，

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

处于所谓的生长期。

And for hair on your head,

对头发而言，

that phase can last up to 6 years.

这个阶段最长可持续 6 年。

But the anagen phase of hair elsewhere on your body,

但身体其他部位毛发的生长期，

eyebrows,

比如眉毛，

eyelashes,

睫毛，

is much shorter,

就短得多，

except in cases like this guy,

不过也有像这位老兄这样的例外，

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

他的眉毛会像头发一样生长，让他创下了世界最长眉毛纪录。

Humans probably lost their fur coats,

人类很可能褪去了那身“毛皮大衣”，

their thick body hair,

也就是浓密的体毛，

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

因为我们在稀树草原上狩猎、奔跑和流汗时，它并没有多少帮助。

And unlike other animals,

而且与其他动物不同，

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

我们人类发现了火，还能制作衣服保暖，不需要自带一件毛皮大衣。

To be sure, 表達脈絡

当然，

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

垂在耳朵和脖子上的长发确实能让你更暖和，

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

但主流理论也认为，头发这么长或许是我们自己造成的，

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

因为早期人类会选择头发能长得更长的对象交配。

Mates that could do that were probably healthier,

能做到这一点的配偶可能更健康，

and in colder climates,

而且在较冷的气候里，

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

他们实际上还自带一顶能为身体保暖的帽子。

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

我最常收到的问题之一，是关于眼睛里的飞蚊，

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

也就是视野中出现的那些小点或弯弯曲曲的细线，

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

尤其是看着晴朗蓝天这类单调背景时。

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

飞蚊是眼睛随年龄增长而产生的细小纤维。

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

你无法直接盯着它们看，因为它们就在眼内的液体中。

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

转动眼球去看，只会让眼内液体跟着移动，飞蚊也会一起移动。

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

但我最喜欢飞蚊的一点是，它们几乎总是微小到肉眼不可见。

You can't see them with the naked eye 習語

你用肉眼看不到它们，

except when they are inside your eye.

除非它们就在你的眼睛里。

If you were to pull an eye floater out, 語法

如果把一条飞蚊从眼睛里取出来，

you wouldn't be able to see it.

你反而看不见它。

But in your eye,

可在眼睛里，

it's close enough to the retina 語法

它离视网膜足够近，

to leave a shadow on the retina,

能在视网膜上投下影子，

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

而你看到飞蚊时，看到的正是这个影子。

Finally,

最后，

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

如果我把 Wikipedia 上的所有文字都打印出来并装订成书，会有多重？

Well, luckily,

好在，

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

Wikipedia 上恰好有一篇文章专门讨论这个话题。

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

英文版 Wikipedia 大约包含 23.45 亿个单词，

which, 語法

如果

if printed at the density of the Encyclopedia Britannica,

按《大英百科全书》的文字密度来印刷，

would equal about 1,759 volumes,

就相当于大约 1,759 卷，

which would look like this.

看起来会是这样。

Altogether,

这些书加在一起，

they would weigh about 7,000 lb.

大约重 7,000 磅。

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

如果你的年龄在 13 到 18 岁之间，

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

不妨了解一下 Google Science Fair。

It's an amazing competition.

这是一项很棒的竞赛。

These guys are great.

这些人都特别厉害。

They actually helped make that Earth Bridge animation for me.

他们还帮我制作了刚才那段“地球桥”的动画。

So, be sure to check out googlesciencefair.com.

所以，一定要去 googlesciencefair.com 看看。

And I'll keep checking out Los Angeles.

我也会继续逛逛洛杉矶。

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

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

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

我们三个人以前从未同时出现在同一个地方，直到现在。

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

所以一定要订阅我们的频道，因为很快就会有精彩视频上线。

And as always, thanks for watching.

一如既往，感谢观看。