《星际穿越》中的科学

When I think about Kepler-186f,
我试着把它想象成一个真实的地方…
I try to imagine it as a real place…
因为它就是个真实的地方
…because it is a real place.
我们知道它会是多岩石的 它有地球同样大小…
We know that it could be rocky, it’s the same size as Earth…
所以我就想象出一个多岩石的表面
…so I do imagine a rocky surface.
我们不知道它有液体海洋 但我们可以想象出一个
We don’t know that it has a liquid ocean, but we can certainly imagine one.
然后突然间 在你的想象中…
And then, all of a sudden in your imagination…
你内在化了那里这个世界的存在…
…you internalize the existence of this world out there…
有一个地方可能会与地球非常像
…that there is a place that could be very, very much like Earth.
那我们什么时候 向这些遥远的彼岸进发呢
So when do we set sail for these distant shores?
真实情况
Reality check.
开普勒-186F距离地球
Kepler-186f is nearly
差不多有3000万亿英里远
3 quadrillion miles from Earth.
换句话说 有500光年远
Otherwise put, 500 light-years away.
那是光速的500年之旅
That’s a journey of 500 years at the speed of light.
但没有东西可以跑得像光那样快
But no thing can travel as fast as light.
我们的航♥天♥器充其量 也要慢数千倍
At best, our spacecrafts are thousands of times slower.
就算《星际穿越》里的宇宙飞船 也不能望其项背
Even the spaceships in Interstellar don’t come close.
我们需要最勇敢的人类 为我们寻找新家园
We need the bravest humans to find us a new home.
但最近的恒星的距离 都超过了千年之远
But the nearest star is over a thousand years away.
-因此要勇敢 -是的
– Hence the bravery. – Okay.
那么他们如何超越我们的太阳系 到达新世界呢
So how do they reach new worlds beyond our solar system?
他们通过走时空弯曲面
They take a walk on the warp side of space and time.
你不知道你什么时候回来
You have no idea when you’re coming back.
难道你没有告诉她 你要去拯救世界
Couldn’t you have told her you were going to save the world?
没有
No.
我会回来的
I’m coming back.
当我们到一个遥远的地方旅行时
When we journey to a far-off place,
我们不仅在空间穿梭 而且在时间…
we travel not just in space but also in time…
当我们跨入未来时
…as we move into the future.
直到大约100年前
Until about a century ago,
科学家还相信时空是完全分开的
scientists believed that space and time were entirely separate.
理论物理学家肖恩·卡罗尔解释
Theoretical physicist Sean Carroll explains
阿尔伯特·爱因斯坦如何推♥翻♥该观点
how Albert Einstein overturned that idea.
爱因斯坦其中一个伟大洞见是
One of Einstein’s great insights…
时空是相互关联的…
…was that space and time were related to each other…
肖恩·卡罗尔 加州理工学院
你有空间 你有时间
…where you have space and you have time.
爱因斯坦说”只有一个东西 我们称之为时空”
Einstein says, “There’s only one thing which we call space-time.”
接着他说”这个时空的东西…
And then he says, “This space-time thing…
它不只是所有情节都上演的舞台
…it’s not just the stage on which all the action plays out.
它是演员本身”
It’s an actor itself.”
时空可以改变 它可以移♥动♥
Space-time can change, it can move,
它可以弯曲 它可以扭曲
it can bend, and it can warp.
爱因斯坦的相对论指出
Einstein’s theory of relativity states
时空就像一块柔性织物
that space-time is like a flexible fabric.
所有物体都嵌在它里面
The objects embedded in it:
太阳 行星 甚至我们 弯曲织物
The sun, planets, even us, warp that fabric.
这种扭曲的后果 就是我们所说的万有引力
And the consequence of that warping is what we call gravity.
物体越大 时空扭曲越大…
The more massive the object, the more space-time is warped…
而引力就越大
…and the greater the gravity.
我们感觉到引力
We feel gravity.
时空的灵活性靠直觉了解比较难…
The flexibility of space-time is harder to grasp on a gut level…
但它的影响是可衡量的
…but its effects are measurable.
正如肖恩论证的 引力越大 时间流逝的速度越慢
As Sean demonstrates, the greater the gravity, the more slowly time flows.
比如说 如果我和一个钟在一楼
For example, if I were on the ground floor with a clock…
一个超精确的原子钟…
…a super accurate atomic clock…
我的双胞兄弟在建筑的顶楼…
…and a twin of mine was up on the top floor of a building…
也和同样精确的原子钟在一起…
…with an equally accurate atomic clock…
如果我们过些时候比较它们 我的钟会比楼顶的钟慢几秒
…if we later on compared them, mine would have ticked off fewer seconds.
肖恩在一楼 比起他在顶楼的双胞兄弟…
On the ground floor, Sean experiences slightly more gravity…
体验了稍微多点的引力
…than his twin on the top floor.
他也比他的双胞兄弟 经历了稍微少的时间
He also experiences slightly less time than his twin.
区别很微小 但真实存在
The difference is tiny, but real.
而且有实际应用
And there are practical applications.
比如GPS系统 即全球定位系统…
For example, the GPS system, the Global Positioning System…
那是非常非常精确的时钟组…
…that is a very, very precise set of clocks…
在卫星上绕地球运行…
…on satellites orbiting around the Earth…
而且该绕行轨道所处的引力场
…and that orbit is in a slightly different gravitational field
跟我们在地面上的稍微不同
than we are in down here.
所以地面上时间的运行速度…
So the fact that time moves differently here on the surface of the Earth…
不同于卫星轨道上的 这一事实非常非常重要…
…than in the satellite orbit, is very, very important…
能够使GPS精确运转
…to getting the GPS to work correctly.
GPS卫星上的时钟 比地球上的时钟走得快…
Time on a GPS satellite clock advances faster than a clock on Earth…
每天快大约38微秒
…by about 38 microseconds per day…
所以该系统的电脑对此做校正
…so the system’s computers correct for that.
运动也影响我们对时空的体验
Motion also affects our experience of space-time.
描述的最佳方法就是静止不动…
The best way to say it is just staying still…
意味着你体验到你能经历大部分时间
…means that you experience the most time that you can.
四处走动做事情 意味着你会经历较少时间
Moving around and doing things means you experience less time.
我们再看肖恩 他在汽车方向盘边
Let’s revisit Sean at the wheel of his car
他的双胞兄弟在公园长椅上
and his twin on a park bench.
如果你从车里出来 然后你回到车上…
If you move out on your oar, and then you come back…
与待在后面的那个人比…
…compared to the person who stayed behind…
你旅行携带的时钟…
…your clock that you took with you on that journey…
与待在后面的人比
…will have experienced a little bit less time
会经历稍微少点的时间
than the one who stayed behind.
我们通常动得太慢 而不会注意到这个影响
We normally move too slowly to notice the effect.
但如果肖恩可以接近光速驾驶…
But if Sean could drive near the speed of light…
他就可以来回穿越美国百万次…
…he could race across the United States and back again a million times…
并经历不到一秒的时间…
…and experience less than a second of time…
而他丢在身后的双胞兄弟…
…while the twin he left behind…
会忍♥耐数小时等待肖恩归来
…would endure hours of waiting for Sean’s return.
换句话说 与双胞兄弟比
In other words, Sean would’ve traveled
肖恩已经到未来旅行了一遭
into the future compared to his twin.
这意味着在未来 太空旅行可能有点复杂
This means space travel may get tricky in years to come.
我们的宇宙飞船飞得越快
The faster our spaceships,
我们遇到的引力场就越大…
the greater the gravity fields we encounter…
我们就可能变得 和落在后面的东西就越不同步
…the further out of sync we may become with those we leave behind.
如果我们找到一个新家园 然后呢
So if we find a home, then what?
每小时是地球上7年的时间
Every hour is seven years back on Earth.
时间的相对性
The relativity of time
是《星际穿越》的艰难和心碎之源
is the source of hardship and heartbreak in Interstellar.
乔纳森·诺兰 《星际穿越》编剧
相对论本身就非常吸引人…
The theory of relativity is fascinating all by itself…
但当你谈论人们之间的距离时…
…but it immediately becomes something very emotional…
它又突然变成 非常容易引起情绪激动的东西
…when you talk about the distances between people.
我们都把时间花在了远离家人的地方
You know, we all spend time away from our families.
我就想 如果你可以接受到它的
I just thought, what if you could take
逻辑的和苦乐参半的极端会怎样
that to its logical and very bittersweet extreme?
对我来说 能够检验时间的主观经历…
For me, it was very exciting to be able to examine the concept…
这令人非常激动
…of the subjective experience of time.
这真的是第一次 围绕电影网有一个目标结构…
It’s really the first time I’ve had an objective structure…
讲述时间实际上是相对的…
…around the film saying that time literally is relative…
我们经历的时间都不一样
…that we all experience time differently depending
取决于我们在宇宙的什么地方
on where we are in the universe.
但时空的弯曲也许也提供了…
But the warping of space-time may also provide shortcuts…
可以使星际旅行瞬间实现的捷径
…that could make interstellar travel a snap.
虫洞
Wormholes.
它们是科幻片的基本特征…
They’re a staple of science fiction…
但它们都基于真正的科学
…but they’re based on real science.
爱因斯坦的相对论定律 规定了时空的弯曲…
Einstein’s relativistic laws govern the warping of space and time…
基普·索恩 加州理工学院
而且他们说虫洞可能存在 它们可以存在
…and they say that wormholes might exist, they could exist.
所以这可以一直追溯到1916年
So this dates all the way back to 1916.
虫洞是时空可以弯曲的特殊途径
A Wormhole is a particular way that space and time can be curved.
这就像加上一个 连接空间两部分的小隧♥道♥
It’s like adding a little tube that connects two parts of space.
基本思路就是
The basic idea is
如果你是一只蚂蚁 你居住在苹果的表面…
that if you’re an ant and you live on the surface of the apple…
苹果的表面就是你的整个宇宙
…the surface of the apple is your entire universe.
你可以绕着外表穿越宇宙…
You can go around the outside through the universe itself…
或者你也可以穿越虫洞
…or you can go through the Wormhole.