If superpowers were real: Body mass - Joy Lin

超能力是不是真的: 身体的质量 - Joy Lin

翻译人员: nancy liu 校对人员: Wenbo Li

Some superheroes can grow

一些超级英雄

to the size of a building at will.

可以随意的把身体变成一座楼那么大

That's very intimidating!

这可真吓人

But a scientist must ask

但是科学家会问

where the extra material is coming from.

那些多余的物质从哪里来？

The Law of Conservation of Mass implies

质量守恒定律表明

that mass can neither be created

质量既不能凭空创造

nor destroyed,

也不能凭空消失

which means that our hero's mass

这意味着我们的英雄的质量

will not change just because his size changes.

并不会因为他身体大小的改变而改变

For instance, when we bake a fluffy sponge cake,

举个例子，当我们烤松软的海绵蛋糕的时候

even though the resulting delicious treat

即使烤出来的美味蛋糕

is much bigger in size than the cake batter

比烤之前的蛋糕糊

that went into the oven,

大了许多

the weight of the cake batter should still equal

蛋糕糊的重量仍然应该

the weight of the cake

等于烤出来的蛋糕的重量

plus the moisture that has evaporated.

加上蒸发掉的水分的重量

In a chemical equation,

在化学方程式中

molecules rearrange to make new compounds,

分子们重新组合来制造新的化合物

but all the components should still be accounted for.

但是反应前后所有物质的质量之和仍然不会变

When our hero expands

当我们的英雄从

from 6 feet tall

6英尺高

to 18 feet tall,

变到18英尺高

his height triples.

他的身高变成原来的三倍

Galileo's Square Cube Law says

根据伽利略的平方立方定律计算

his weight will be 27

他的重量会变为原来的27倍

- 3 times 3 times 3 equals 27 -

3x3x3＝27

times his regular weight

乘上他原来的重量

since he has to expand in all three dimensions.

因为他必须在三个维度都变大

So, when our superhero transforms into a giant,

因此，当我们的超级英雄变成一个巨人

we are dealing with two possibilities.

有两种可能性

Our hero towering at 18 feet

我们的超级英雄有18英尺那么高

still only weighs 200 pounds,

但只有200磅那么重

the original weight in this human form.

和他没变大的时候一样重

Now, option two, our hero weighs 5,400 pounds

还有，第二种可能，我们的英雄重5400磅

- 200 pounds times 27 equals 5,400 pounds -

200磅乘7＝5400磅

when he is 18 feet tall,

当他高18英尺的时候

which means he also weighs 5,400 pounds

这也意味着在他只有6英尺高的时候

when he is 6 feet tall.

他还是重5400磅

Nobody can get in the same elevator with him

如果不想超载

without the alarm going off.

他就只能自己坐电梯

Now, option two seems a little more

现在，第二种可能性

scientifically plausible,

看起来更佳符合科学事实

but it begs the question,

但是这种情况依旧回避了一些问题

how does he ever walk through the park

在他在公园散步的时候

without sinking into the ground

他如何保持自己不会陷进地里？

since the pressure he is exerting on the soil

由于他对泥土施加的压强

is calculated by his mass

等于他的质量

divided by the area of the bottom of his feet?

除以他脚底的面积

And what kind of super socks and super shoes

而且他得穿什么样的超级袜子和超级鞋

is he putting on his feet to withstand all the friction

才能承受得了他在奔跑的时候

that results from dragging his 5,400 pound body

他那5400磅的身体

against the road when he runs?

和道路之间的摩擦？

And can he even run?

他能跑步么？

And I won't even ask how he finds pants

我不会问他能不能找到足够有弹性的裤子

flexible enough to withstand the expansion.

来承受他的变形

Now, let's explore the density

现在，我们探究一下

of the two options mentioned above.

之前我们提到的两种情况中的密度

Density is defined as mass divided by volume.

密度的定义是质量除以体积

The human body is made out of bones and flesh,

人的身体由骨头和血肉组成

which has a relatively set density.

这两部分的密度都是确定了的

In option one, if the hero weighs 200 pounds all the time,

第一种情况中，如果这个英雄一直都重200磅

then he would be bones and flesh at normal size.

那么他的骨头和血肉都和正常一样

When he expands to a bigger size

当他变大之后

while still weighing 200 pounds,

而且仍然只有200磅

he essentially turns himself

他基本上就是把自己

into a giant, fluffy teddy bear.

变成了一个超大超软的泰迪熊

In option two, if the hero weighs

在第二种可能中，如果这位英雄

5,400 pounds all the time,

一直都重5,400磅

then he would be bones and flesh at 18 feet

那么，当他的身高18英尺时

with 5,400 pounds of weight supported by two legs.

他需要用两条腿支撑5,400磅的身体

The weight would be exerted on the leg bones

当他从不同角度活动时

腿骨需要承受如此之大的重量

at different angles as he moves.

Bones, while hard, are not malleable,

骨，又硬又没有延展性

meaning they do not bend,

这代表它们无法弯曲

so they break easily.

因此它们易碎

The tendons would also be at risk of tearing.

筋也有可能被撕裂

Tall buildings stay standing

高大的建筑之所以可以耸立

because they have steel frames

是因为他们有钢架

and do not run and jump around in the jungle.

并且不会在丛林里跑跑跳跳

Our hero, on the other hand,

而我们的英雄呢

one landing at a bad angle

一旦从一个不太好的角度着了陆

and he's down.

他就会摔倒

Assuming his bodily function is the same as any mammal's,

假设他的身体构造和哺乳动物的一样

his heart would need to pump a large amount of blood

他的心脏需要提供大量的血液

throughout his body to provide enough oxygen

在身体里循环来提供足够的氧气

for him to move 5,400 pounds of body weight around.

来支持他那5,400磅的身体行动

This would take tremendous energy,

这将需要他

which he would need to provide

每天通过吃27x3000卡路里的食物

by consuming 27 times 3,000 calories of food every day.

来提供这巨大的能量

Now, that is roughly 150 Big Macs.

粗略地计算大概是150个巨无霸汉堡所含的能量

27 times 3,000 calculated equals

27x3000＝81000

81,000 calculated slash 550 calories

81000÷550

equals 147.

＝147

He wouldn't have time to fight crime

他将没有时间和罪犯斗争

because he would be eating all the time

因为他所有的时间都用来吃东西了

and working a 9-to-5 job

并且找一份朝九晚五的工作

in order to afford all the food he eats.

来支付在他食物上的花销

And what about superheroes

那么，像那些可以

who can turn their bodies into rocks or sand?

把身体变成沙子或者石头的超级英雄呢

Well, everything on Earth is made out of elements.

地球上的所有东西都由各种各样的元素组成

And what defines each element

而决定每一种元素种类的

是原子核中的质子数

is the number of protons in the nucleus.

That is how our periodic table is organized.

这也是元素周期表排列的规则

Hydrogen has one proton,

氢元素有一个质子

helium, two protons,

氦元素，两个质子

lithium, three protons,

锂元素，三个质子

and so on.

等等

The primary component of the most common form

沙子最基本形式的基础成分

of sand is silicon dioxide.

是二氧化硅

Meanwhile, the human body consists of

然而，人体由

65% oxygen,

65％的氧元素

18% carbon,

18％的碳元素

10% hydrogen,

10％的氢元素

and 7% of various other elements

和7％的其它种类的元素组成

including 0.002% of silicon.

包括0.002％的硅元素

In a chemical reaction,

在化学反应中

the elements recombine to make new compounds.

元素重新组合形成新的物质

So, where is he getting all this silicon

那么，他要从哪弄到这些必要的硅元素

necessary to make the sand?

来制造沙子

Sure, we can alter elements

当然，我们可以通过核裂变或核聚变

by nuclear fusion or nuclear fission.

来改变元素的种类

However, nuclear fusion requires so much heat,

然而，核聚变需要非常高的温度

the only natural occurrence of this process is in stars.

以至于唯一可以自发聚变的地方在星体上

In order to utilize fusion in a short amount of time,

为了在短时间内进行聚变

the temperature of the area

反应区域的温度

needs to be hotter than the Sun.

需要比太阳还高

Every innocent bystander will be burned to a crisp.

每个无辜的旁观者都会被烧成脆片

Rapid nuclear fission is not any better

快速的核聚变反应有很多缺点

since it often results in many radioactive particles.

因为它会产生许多放射性微粒

Our hero would become

我们的英雄就会变成

a walking, talking nuclear power plant,

一个会行走，会说话的核电站

ultimately harming every person he tries to save.

基本上会伤害每一个他试图去救的人

And do you really want the heat of the Sun

并且你真的想要太阳那么高的热度

or a radioactive nuclear plant inside of your body?

或者一个放射性的核电站在你身体里面么？

Now, which superpower physics lesson

现在，你还想参加哪一种

will you explore next?

超能力的课程？

Shifting body size and content,

改变身体的大小和构成身体的物质

super speed,

超快的速度

flight,

飞行

super strength,

力大无比

immortality,

长生不老

and

还是

invisibility.

隐身