BBC 地平线系列：时空谜团（2008）

我们生活中有一个方面是我们大家都不假思索的
There's an aspect of our lives that we all take for granted.
它太熟悉不过了 你通常是不会予以重新考虑的
It's something so familiar, you usually don't give it a second thought.
作为人类的一个关键要素就是我们看得懂时间
One of the key elements of being a human being is that we can tell the time.
它让我们明白世界 -
It allows us to make sense of the world -
过去 现在和将来
past, present and the future.
然而它绝非你想象的那样简单
But it's nowhere near as straightforward as you might think.
我是布赖恩·考克斯教授 我要来揭示时间的秘密
I'm Professor Brian Cox and I want to find out what makes time tick.
我们具备了测量时间推移的手段
We have ways to measure the passing of time
但是我们无法知道时间推移时会发生什么事情
but we don't know what happens when time passes.
我甚至此刻都无法告诉你 此刻究竟是指什么
I can't even tell you at the moment what at the moment means.
就是眼下
Even momentarily.
了解事件谈何容易
Knowing the time is not easy.
我非常肯定所谓时间的推移最终是个假象
I' damned sure that flow of time is ultimately an illusion.
空中没有什么大钟在滴答作响
There's no big clock in the sky which ticks away at the same rate
对人们来说 无论他们在哪里或在干什么
for everybody, no matter where they are or what they're doing.
时间有起点吗？
Did time have a beginning?
为什么时间在走呢？
Why does time tick?
我们的未来早已存在了吗？
And does our future already exist?
我将尝试回答你可能会提出的一个最简单的问题 -
I'm going to try and answer one of the simplest questions you could ask -
“时间是什么？”
"What time is it?"
你了解时间吗
BBC - Horizon 2008 - Do You Know What Time It Is
现在几点钟？　5:58
So, what time is it now? It's 5:58.
我们几时到那里？
What time have we got to be there?
日出是6:11
The sun rises at 6:11.
所以我们还有13分钟
So we've got about 13 minutes.
“时间是什么”这个问题 人类已经思索了数千年
"What time is it?" is a question that humanity has asked for millennia.
我们许多古文明已经不遗余力地
Many of our ancient civilisations went to great lengths
试图回答这个简单的问题
to try and answer this simple question.
没有人比得上玛雅人的
None more so than the Maya.
我来到了墨西哥尤卡坦半岛 来考察奇琴伊察的古代玛雅神庙
I've come to the Yucatan Peninsula of Mexico to see the ancient Mayan temples at Chichen Itza.
你通常是不允许做这个的
You're not usually allowed to do this.
但是因为现在是早晨6点钟 这里没有什么人
But because it's 6am and there's nobody here,
我们获准登上金字塔
we've got permission to walk up the pyramid.
真是不可思议
It's just absolutely incredible.
玛雅人有个对时间的情结 创造了复杂的方法来跟踪时间
The Maya had an obsession with time, working out intricate ways to track its passing.
玛雅人没有钟表 不知道如何制♥作♥计时器
The Maya didn't have clocks, they didn't know how to build timepieces.
但是他们利用周围的世界来精确地计时
But they used the world around them to keep time extremely precisely.
他们锁定时间的循环 难以置信的复杂
And they had interlocking cycles of time, incredibly complicated, that were based on the movement of
就是基于所能见到的天上所有明亮的天体的运行
all the bright celestial objects you can see in the sky.
如果你认为我们的人生受到时间左右的话
If you think our lives are ruled by time,
那么玛雅人对时间的崇拜达到了全新的水平
the Maya took time worship to a whole new level.
他们不光跟踪时间的推移
They didn't just track its passing.
他们认为他们必须帮助时间的推移
They believed they had to help time pass.
他们认为时间其实是在创造空间
They thought that time actually created space
他们认为必须去供奉太阳 以帮助它越过天空 目的是为了创造空间
and they thought that they had to feed the sun, to help it go through the sky, in order to make the space,
也就是创造他们的世界
you know, make their world.
他们用血 用人血来供奉太阳
And they fed the sun with blood, with human blood.
他们用活生生的供品给太阳 以支持它越过天空
So they made blood sacrifices to the sun to kind of sustain it on its journey across the sky.
那些就是他们掌握时间的固定方法
Such was their fixation with knowing the time,
时间本身就体现在玛雅的建筑上
that time itself is manifest in Mayan architecture.
这个建筑的一切都与时间有关
Everything about this building is about time.
91个台阶 建造有4个面
There are 91 steps on the way up and there are four sides to the building.
四个91级 就是36♥4♥ 加上顶上的一级 就是365
That's four 91s, 36♥4♥, and then one step at the top to make 365.
所以建筑本身就直截了当地表示了时间的推移
So the building itself is
这就是我行程的第一站
This is the first stop on my journey
试图回答最早存在的很简单的问题
to try and answer what appears at first to be a very simple question.
报时是玛雅人认为自己已经掌握了的东西
Telling the time was something the Maya thought they'd mastered.
然而这并非如你想象的那么简单
But it's not as easy as you might think.
我想知道时间是什么
I'd like to understand what time is.
这是个苛刻的想法
And it's a very tall order.
世界上一些最优秀的物理学家正致力于这个很简单的问题 -
Some of the best physicists in the world are working on that really simple question -
时间是什么？
what is time?
2000年前 玛雅人认为自己已经知道了
And the Maya thought they knew,
400年前 牛顿认为自己知道了
Newton thought he knew 400 years ago.
爱因斯坦在1915年六个月里有点认为自己知道了
Einstein kind of thought he knew for about six months in 1915
但是在1916年他改变了主意
and then changed his mind in 1916.
这个问题至今困惑着我们
And it's a problem that's confounded us to this day.
确实不知道
This is truly the unknown.
时间是什么？
What time is it?
我不知道
I don't know.
你知道吗？
Do you know?
自有文明以来 每一种文化都在抬头审视时间的推移
Since the dawn of civilisation, every culture has tracked the passing of time by looking up.
随着地球的旋转 太阳 月亮 星星越过天空
As the earth rotates, the sun, moon and stars move across the sky,
给我们以一个昼夜的节律 - 直觉告诉我们时间的方法
giving us a daily rhythm - an instinctive way to tell the time.
所以你想知道时间是什么 无需手表 无需时钟
So if you want to know what time it is, you don't need a watch, you don't need a clock.
你只需要抬头看太阳 有规律地日出日落 每天都在运行的时钟
You just need to look up at the sun, that regular rising and setting, the clockwork of the passing of the day.
然而实际上 结果是那个规律 每天的长度
But actually, it turns out that that regularity, the length of the day,
并非你想象的那么精准
isn't quite as precise as you might think.
在过去的40亿年里 我们地球的旋转速度一直在慢下来
For the last four billion years or so, the speed our planet spins has been gradually slowing down.
每天的长度逐步变长
The length of a day has been steadily getting longer.
这都归咎于月亮
It's all down to the moon.
你瞧 月亮将地球表面的水拉向它 所以就产生了潮汐
You see, the moon holds the water on the surface of the earth towards it so you get a tidal bulge.
地球的旋转受到隆起的影响 这样 你就看到了潮起潮落
And the earth spins underneath that bulge and that's what you see as the tide's coming in and out.
地球表面和水之间产生摩擦
And there's friction between the surface of the earth and the water
这就意味着 地球的旋转速度随之减慢
which means that the spin, or the rate of spin of the earth, slows down.
这就造成了每天延长了
And that causes the day to lengthen.
6亿年前 每天长度不足22小时
600 million years ago, the day was just under 22 hours long.
然而地球不只是在数百万年里慢下来
But the earth isn't just slowing down over millions of years.
要紧的是我们所依赖的时间
The very thing that we relied on for telling the time,
那个地球围绕其轴心旋转一周是24小时的事实
the fact that the earth takes 24 hours to spin once on its axis,
我们现在意识到了我们无法继续依赖了
is something we now realise we can't rely on even from day to day.
在过去30年里 测量每天的精确长度已经成了
For the last 30 years, measuring the exact length of each day has been the job of scientists
马萨诸塞州波士顿北部韦斯特福德天文台的科学家的工作了
at the Westford Observatory, just north of Boston, Massachusetts.
有许多不同的方法来测量地球的旋转
There are lots of different ways of measuring the spin of the earth
然而奇怪的是 最好的方法之一就是寻找
but strangely, one of the best is to look for light
很久以前发出的光
that began its journey a long time ago,
来自遥远的星系
from a galaxy far, far away.
不同于玛雅人 这里的科学家 并不依靠跟着地球旋转的太阳
Unlike the Maya, the scientists here don't rely on the sun to track the spin of the earth.
为了进行这样的测量 你就需要有尽可能稳定 尽可能远的东西
To make these measurements, you need something that's as steady as possible, as far away as possible.
当然 要尽可能亮 最亮的东西
So, as bright as possible. And the brightest things
我们知道在宇宙中 这类东西叫做类星体
we know of in the universe are these things called quasars.
我们认为它们是星系的核
They're, we think, the nuclei of galaxies.
巨大的黑洞 吞噬着大量的尘埃和星星 抛射出电波
So, a big, huge black hole, sucking loads of dust and stars into them, throwing out radio waves.
显然我们可以利用这些电波 知道地球上的时间
And it's those radio waves that we actually use, remarkably, to tell the time on the earth.
谢谢
Thanks.
阿瑟·尼尔是记录时间的人
Arthur Niell is the man who keeps track of time.
噢 照顾好自己的耳朵 这里有点吵
Oh yeah! Mind your ears, probably pops just now.
这里好像是密闭舱 就是密闭舱
This is like an airlock. It is an airlock.
你们是如何进行测量的？
How do you make this measurement?
我们其实是利用两架射电望远镜
What we actually use are two radio telescopes,
实际上是两架以上 但是用上两架射电望远镜就可以了
actually two or more, but with two radio telescopes, we can do this.
我们测量的是来自太空的电波
And what we measure is this radio wave coming in from space.
接收到电波 我们就会看到即时的时间
As it comes in, we look to see the instant of time when this radio wave
只要电波同时分别抵达两个望远镜
arrives at the same time at two different telescopes.
只要类星体出现在头顶 电波就会同步抵达
When a quasar is directly overhead, the radio waves arrive at the two
这两架望远镜 秒表就会校准时间
separate telescopes in synch and the stopwatch is set running.
随着地球的旋转 电波会同步漂移
As the earth spins, the radio waves drift out of synch,
抵达各个望远镜会有时差
taking different times to reach each telescope.
但在转满一圈后
But after one full rotation,
两架望远镜同步归位 时钟停止了
the two telescopes are back in synch and the clock is stopped.
这就给了你地球旋转一周的精确时间 -
This gives you the exact time for one rotation of our planet -
一天
one day.
但是从来没有完全相同过
But it's never quite the same.
有时 会提早些 有时会稍微晚一些
Sometimes, you get there a little early and sometimes you get there
相对地球上的时钟 它击打出很有规律的节律
a little bit late relative to the clock we have on earth that's beating out very regular seconds.
所以 24小时...
So, 24 hours...
经过24小时 你会想
You come round 24 hours and you think,
“噢 我们还是有差距的”
"Uh-oh, we're not quite there yet. "
所以 地球的旋转差了那么一点点
And so, the earth rotates a little bit more.
有时 它会转得快一点
Sometimes, it speeds up a little and gets there a earlier