How fast are you moving right now? - Tucker Hiatt

翻译人员: Tianchang Luo 校对人员: Chen Zou

How fast are you moving right now?

此时此刻你移动得有多快？

That seems like an easy question.

这似乎是个简单的问题

The first tempting answer is,

第一反应得到的答案是

"I'm not moving."

“我并没有移动。”

Upon further reflection,

经过更一步的思考后

you realize that maybe the Earth's motion counts.

你意识到可能地球的运动要算进去

So, a second tempting answer is,

所以，第二个容易想到的答案是

"19 miles/second around the Sun."

“以19英里每秒的速度围绕太阳运动。”

But then you recall learning that the Sun

但是马上你又回想起曾经学过

moves around the center of the Milky Way galaxy,

太阳绕着银河系的中心运动

and the Milky Way moves within the Local Group of galaxies,

银河系在本星系群中运动

and the Local Group moves within the Virgo Cluster,

而本星系群又在室女座星系团中运动

and the Virgo Cluster moves within...

室女座星系团运动在……

"How fast are you moving?"

“你移动得有多快？”

is not an easy question.

不是一个简单问题

When Mission Control tells astronauts

当太空航行地面指挥中心告诉宇航员

how fast they're going,

他们的运动速度时

there's always an assumed standard of rest.

总会有个关于静止的假定标准

At the start of the voyage,

在航行的一开始

speeds are given relative to the launchpad.

速度是以发射台作为参照给出的

But later, when the launchpad is

但随后，当发射台只不过是

just one more arbritrary place

在地球旋转表面上的

down there on Earth's spinning surface,

又一个任意的地点时

speeds are given relative to

速度的给出是根据

the idealized, non-spinning pinpoint center of Earth.

理想状态下的，停止运转的地球的中心

On their way to the Moon,

在驶向月球的旅途中

Apollo astronauts had a hard time

阿波罗号宇航员们发现很难

answering the question,

回答这个问题

"How fast are you moving?"

“你移动得有多快？”

Speed away from Earth was one thing,

从地球出发是一个速度

and speed toward the Moon was quite another.

驶向月球又是另一个速度

That's because the Earth and the Moon

这是因为地球和月球

move relative to one another.

相对于彼此运动

Ah, of course!

理所当然的

Speed is a relative quantity.

速度是一个相对量

When Captain Kirk ask Lieutenant Sulu

当Krik船长询问中尉Sulu

if the Starship Enterprise has reached a speed of warp 7,

企业号星舰是否达到曲速7级的速度时

Sulu should reply,

Sulu本应该回答

"Relative to what, Captain?"

“相对于什么而言，船长？”

Such a sassy reply

如此无礼的回答

may get subordinate Starfleet officers in trouble,

只怕会让星际舰队的下级官员们惹上麻烦

but it is the only good answer

但它却是“你移动得多快？”这个问题

to the question, "How fast are you moving?"

唯一的好答案

This is basic relatively talking.

这基本的相对说法

Not fancy Einsteinian relativity,

不是大名鼎鼎的爱因斯坦相对论

but good old fashioned (and still correct)

但也是守旧的（而且至今仍然是正确的）

Galilean relativity.

伽利略相对性原理

Galileo seems to have been the first person

伽利略似乎是第一个

to realize that there is no such thing

认识到绝对速度

as an absolute speed.

是不存在的人

Speeds are relative.

速度是相对的

This means that speeds only have meaning

这就意味着当速度与参考系

when they are referred to a reference frame.

联系起来时它们才具有意义

Presumably that reference frame is itself at rest.

假定这个参考系自身是静止的

But then we have to ask again,

但我们又要问

"At rest relative to what?"

“静止相对于什么？”

Because even the concept of rest

因为即使静止这个概念

has lost any hint of absolute meaning.

已经失去了任何绝对的意义

Speed is relative, and rest is relative.

速度是相对的，静止也是相对的

Earth's speed is 19 miles/second relative to the Sun.

地球以19英里每秒的速度的绕太阳公转

The Enterprise's speed is warp 7

企业号飞船的速度是曲速7级

relative to the center of the Milky Way galaxy.

相对于银河系的中心

Your speed is zero relative to your easy chair.

你的速度相对于你坐的椅子为零

But depending on where you sit,

但是根距你坐的地方

相对于地球中心，你的速度是几百英里每小时

it is hundreds of miles/hour relative to Earth's center.

When we furrow a brow and ask,

当我们皱着眉毛然后问

"But how fast is Earth really moving?"

“那么地球究竟移动得有多快？”

we imagine Spaceship Earth

我们把地球想象成一艘飞船

plowing through the ocean of space

在宇宙的海洋中乘风破浪

as it orbits the Sun.

在绕着太阳公转的同时

But space is not an ocean.

但宇宙不是海洋

It has no substance as water does.

它不像水一样由物质构成

Space is not a thing;

宇宙不是一个事物

space is nothing.

宇宙什么都不是

Space is no thing.

宇宙没有事物

You can move between two points in space,

你能在宇宙中的两个点之间任意移动

say between Earth and Mars,

假如说在地球和火星之间

but you can't move through space.

但你不能穿过宇宙

There's nothing to move through.

没有什么可以穿过的

It's like trying to say how much a hole weighs.

就好像是在说一个洞有多重

A hole weighs exactly nothing

一个洞是没有重量的

because a hole is nothing.

因为一个洞什么也不是

It's a void, and so is space.

它是无效的，宇宙也是

To move relative to nothing is meaningless.

没有参照系的移动是毫无意义的

The concepts of speed and of rest

加速和静止的概念

have only relative meaning.

只有相对意义

They are absolutely meaningless.

它们从绝对意义上说是无意义的

They mean something

它们的意义

only with respect to arbitrarily chosen,

只存在于任意选中的

artificial frames of reference.

人工参照系中

If, someday, you are buckled into your spaceship,

如果有一天，你坐在宇宙飞船中

and you see from the side window, say,

你从舷窗看到

a space station whizz by at constant speed,

一个宇宙空间站匀速飞过

there is no way to know which of you is really moving.

没有办法确定你们中的哪一个是在真正移动

Neither of you is really moving

你们都没有在真正运动

because there is no deep reality about constant speed.

因为关于匀速并没有深刻的现实意义

Constant speed in a straight line

在一条直线上的匀速

has only relative meaning,

只有相对意义

a kind of relative reality.

就好像是一种相对的现实

Does this mean that all motion is relative?

这意味着所有运动都是相对的吗？

No! Some motions have only relative meaning,

不是！一些运动有相对意义

but some motions have absolute meaning,

但是一些运动有绝对意义

are absolutely real.

是绝对真实的

For example, constant speed is relative,

比方说，匀速运动是相对的

but change in speed is absolute.

但速度的改变是绝对的

Calling something absolute in science

在科学上，把一件事称作为绝对

means that arbitrary standards are not used

意味着任意的标准没有被运用

in its measurement.

在它的测量上

It is unambiguously measurable.

它是完全清晰可量的

When your spaceship fires its engines,

当你的宇宙飞船发动时

your change in speed is beyond doubt.

你在速度上的变化是毫无疑问的

You feel it in your stomach,

你感受到你的胃在翻腾

and your ship's sensors can measure it.

而且你的飞船感应器可以测量出这一变化

Outside your window,

在你的窗外

the passing space station

和你擦肩而过的宇宙空间站

may seem to be changing speed,

看起来可能也在发生速度变化

but the beings inside the station will not feel it.

但置身于空间站之内不会感受到

And no sensors can measure it.

而且也没有任何感应器可以测量它

You are really changing speed,

你是真的在发生速度变化

and they are really are not.

它们确实没有

There's something absolutely real

关于速度变化有些

about changes in speed.

东西是绝对真实的

The same goes for rotation.

飞船的旋转也一样

If your spaceship is spinning,

如果你的飞船在旋转

you can feel it,

你是能感受到的

and your ship's sensors can measure it.

飞船上的感应器也可以测量

The space station outside

在空间站外面的一切

may seem to be going around you,

看起来在围着你转

but it is you who feels queasy,

但你却是感到头晕眼花的那一个

not the folks in the space station.

而不是空间站里的人们

You are really spinning,

你确实在旋转

and they really are not.

他们真的没有

There's something absolutely real about rotation.

这就是旋转里面的绝对真实

So, some motions are relative, and some are not.

所以，有些运动是相对的，有些不是

There is no deep reality about constant speed,

对于匀速，并没有深刻的现实性

but changes in speed are deeply real,

但速度的变化却再真实不过了

and so are rotations.

旋转也是

我们必须考虑周全

We have to be thoughtful

in our analysis of everyday experience

在日常经历的分析中

in order to identify what is deeply real.

为了确定什么是有深刻真实性的

Since we can be fooled by perceptions

由于我们会被知觉所迷惑

as basic as speed,

比如基本的速度

maybe every perception deserves careful scrutiny.

也许对每一个知觉都应该加以仔细的审查

This is what inspired Einstein

这启发了爱因斯坦

to his incredible insights

提出了关于

about the speed of light and forward time travel.

光速和到未来旅行的不可思议的见解

Knowing how to identify

知道如何分辩

what is deeply real

什么是深刻的真实

is tough and important work.

是一个艰难而且重要的工作

If a police officer ever pulls you over for speeding

如果你因为超速被警察拦下

然后被问“你知道你开的有多快吗？”

and asks, "Do you know how fast you were going?"

an insightful, though perhaps unwise, reply

一个有深刻见解的，尽管可能不明智的回答

would be, "Relative to what?"

会是，“相对于什参照系？”

And then, as you sit in the backseat of the police car

然后，当你坐在警车的后座上

and feel it accelerate toward jail,

感受到正在加速前往拘留所的时候

you can add,

你可以再说一句

“但是有些事是绝对的！”

"But some things are absolute!"