Andrew Connolly: What's the next window into our universe?

84,386 views ・ 2014-09-16

TED


请双击下面的英文字幕来播放视频。

翻译人员: Li Zhang 校对人员: Yiding(Eden) Wen
00:13
So in 1781, an English composer,
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1781年,一位名叫威廉·赫歇尔的
00:16
technologist and astronomer called William Herschel
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英国作曲家、科学家、 天文学家,
00:19
noticed an object on the sky that
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发现浩渺宇宙一微物,
00:21
didn't quite move the way the rest of the stars did.
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并不像其它星辰,那般移动。
00:24
And Herschel's recognition that something was different,
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他意识到这
00:27
that something wasn't quite right,
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与已知不符。
00:29
was the discovery of a planet,
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藉由此,他发现了一颗行星——
00:31
the planet Uranus,
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天王星。
00:33
a name that has entertained
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它的名字给
00:34
countless generations of children,
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数代儿童带来快乐,
00:37
but a planet that overnight
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而这颗行星的发现,一夜间
00:40
doubled the size of our known solar system.
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将太阳系的已知面积,扩大了两倍。
00:42
Just last month, NASA announced the discovery
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就在上个月,美国国家航天局宣布:
00:44
of 517 new planets
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在附近的恒星轨道上,
00:46
in orbit around nearby stars,
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发现了五百一十七颗新行星。
00:48
almost doubling overnight the number of planets
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这几乎于一夜之间,将我们星系,已知
00:51
we know about within our galaxy.
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行星的数量,翻了一倍。
00:53
So astronomy is constantly being transformed by this
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这种数据收集的能力,
00:56
capacity to collect data,
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正不断改变着天文学。
00:58
and with data almost doubling every year,
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随着数据逐年递增,
01:01
within the next two decades, me may even
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我们甚至开始设想, 在接下来的二十年内
01:02
reach the point for the first time in history
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我们可能有史以来第一次,
01:05
where we've discovered the majority of the galaxies
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探索到宇宙的
01:08
within the universe.
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绝大部分星系。
01:09
But as we enter this era of big data,
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但当我们迈入,这个大数据时代,
01:12
what we're beginning to find is there's a difference
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忽而惊觉:
01:14
between more data being just better
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更多的数据,可以带来好处,
01:17
and more data being different,
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也可能带来不同。
01:19
capable of changing the questions we want to ask,
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并能提出新的问题。
01:22
and this difference is not about how much data we collect,
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关键并不在于,我们收集了多少数据。
01:25
it's whether those data open new windows
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而是,这些数据是否为我们认识宇宙,
01:27
into our universe,
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打开了一扇新的窗户,
01:28
whether they change the way we view the sky.
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又是否能,改变我们认识天空的方式。
01:31
So what is the next window into our universe?
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那么,下一扇宇宙之窗将会是什么?
01:34
What is the next chapter for astronomy?
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天文学的下一篇章将会是什么?
01:37
Well, I'm going to show you some of the tools and the technologies
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在此,我将向你们展示,
01:40
that we're going to develop over the next decade,
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今后十年,我们将开发的一些新工具及新技术。
01:42
and how these technologies,
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并向你们展示,这些技术和
01:44
together with the smart use of data,
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数据的灵巧运用
01:46
may once again transform astronomy
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将如何再次改变天文学,
01:49
by opening up a window into our universe,
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并开启一扇认识宇宙的新窗户——
01:51
the window of time.
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时间之窗。
01:53
Why time? Well, time is about origins,
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为什么是时间?嗯,时间关乎起源,
01:55
and it's about evolution.
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进化。
01:57
The origins of our solar system,
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我们太阳系的起源于何?
01:58
how our solar system came into being,
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它是如何出现的?
02:01
is it unusual or special in any way?
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它有何特殊性,又有何与众不同之处?
02:04
About the evolution of our universe.
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而我们的宇宙呢?
02:06
Why our universe is continuing to expand,
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为什么我们的宇宙还在不停地膨胀?
02:09
and what is this mysterious dark energy
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促使宇宙膨胀的那个神秘的暗能量,
02:11
that drives that expansion?
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究竟是什么?
02:14
But first, I want to show you how technology
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首先,我想向你们展示一下科技,
02:16
is going to change the way we view the sky.
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将如何改变我们观察天空的方式。
02:19
So imagine if you were sitting
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想象一下,
02:21
in the mountains of northern Chile
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你坐在智利北部的山上,
02:23
looking out to the west
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拂晓时分,
02:24
towards the Pacific Ocean
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你向西凝望,
02:26
a few hours before sunrise.
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细观太平洋。
02:29
This is the view of the night sky that you would see,
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你将会看到,这样
02:32
and it's a beautiful view,
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壮观的夜空:
02:34
with the Milky Way just peeking out over the horizon.
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银河刚刚露出地平线,
02:37
but it's also a static view,
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静默安然。
02:39
and in many ways, this is the way we think of our universe:
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而这,就是我们对宇宙的印象:
02:42
eternal and unchanging.
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永恒且不变的。
02:44
But the universe is anything but static.
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但实际上,宇宙并不静止。
02:46
It constantly changes on timescales of seconds
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它在不停地变化。小至按秒,
大至十亿年。
02:48
to billions of years.
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02:50
Galaxies merge, they collide
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星系融合,他们以
02:52
at hundreds of thousands of miles per hour.
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每小时几十万英里的速度相互碰撞,
02:55
Stars are born, they die,
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新的恒星诞生、消亡。
02:57
they explode in these extravagant displays.
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它们以极其华丽的方式爆炸。
03:00
In fact, if we could go back
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实际上,如果我们回首
03:01
to our tranquil skies above Chile,
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凝望,智利宁静的天空,
03:04
and we allow time to move forward
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并让时间前进,
03:06
to see how the sky might change over the next year,
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观测天空接下来一年的变化。
03:11
the pulsations that you see
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你们看到的脉动形状,
03:13
are supernovae, the final remnants of a dying star
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将是超新星-濒临消亡的恒星们,爆炸时最后遗留的部分-
03:17
exploding, brightening and then fading from view,
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它们发出光亮,然后渐渐褪去。
03:21
each one of these supernovae
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每一颗超新星的亮度,
03:23
five billion times the brightness of our sun,
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都是太阳的五十亿倍。
03:26
so we can see them to great distances
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所以我们可以在很远的地方看到它们
03:28
but only for a short amount of time.
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昙花一现。
03:31
Ten supernova per second explode somewhere
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在宇宙中,每一秒,
03:33
in our universe.
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都会有十颗超新星爆炸。
03:35
If we could hear it,
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如果我们能够听到的话,
03:36
it would be popping like a bag of popcorn.
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这就像在爆一袋爆米花一样。
03:40
Now, if we fade out the supernovae,
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现在,如果我们忽略超新星的画面,
03:43
it's not just brightness that changes.
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变化的可不仅仅是亮度,
03:46
Our sky is in constant motion.
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连我们的天空也在持续变化。
03:49
This swarm of objects you see streaming across the sky
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流淌过天空的这一串物什,
03:52
are asteroids as they orbit our sun,
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是围绕太阳运转的小行星,
03:54
and it's these changes and the motion
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是这些天体的变化和运行,
03:56
and it's the dynamics of the system
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以及,这一系统的动态变化,
03:59
that allow us to build our models for our universe,
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让我们能够建造宇宙的模型,
04:01
to predict its future and to explain its past.
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并用于预测宇宙的未来、同时解释其过去。
04:05
But the telescopes we've used over the last decade
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但是,过去十年来,我们所用的望远镜,
04:08
are not designed to capture the data at this scale.
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并非是设计以捕捉这一规模数据的。
04:12
The Hubble Space Telescope:
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哈勃太空望远镜在
04:14
for the last 25 years it's been producing
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过去二十五年里拍摄了
04:16
some of the most detailed views
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我们的宇宙里
04:18
of our distant universe,
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最细致的画面。
04:20
but if you tried to use the Hubble to create an image
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但如果你试图用哈勃望远镜来创作一张
04:22
of the sky, it would take 13 million individual images,
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天空的图像,这将需要一千三百万张的独立相片,
04:27
about 120 years to do this just once.
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并花上大约一百二十年的时间来完成。
04:30
So this is driving us to new technologies
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所以,这驱使我们研发新的技术,
04:33
and new telescopes,
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和新的望远镜,
04:35
telescopes that can go faint
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这是一种既有深度又有广度的望远镜,
04:36
to look at the distant universe
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它能以最快的速度,
04:38
but also telescopes that can go wide
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捕捉到
04:41
to capture the sky as rapidly as possible,
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尽为宽广的画面。
04:43
telescopes like the Large Synoptic Survey Telescope,
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例如,大型综合巡天望远镜,
04:47
or the LSST,
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亦称为LSST,
04:49
possibly the most boring name ever
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是天文学历史上,
04:51
for one of the most fascinating experiments
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最伟大的实验之一。
04:53
in the history of astronomy,
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这个名字相当无趣,
04:55
in fact proof, if you should need it,
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事实证明,如果要取名字,
04:57
that you should never allow a scientist or an engineer
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绝不能让一个科学家或工程师,
05:00
to name anything, not even your children. (Laughter)
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来给任何事物取名。你的小孩就更不要, 让他来啊(大笑)。
05:06
We're building the LSST.
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我们正在建造LSST,
05:07
We expect it to start taking data by the end of this decade.
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我们预计,在这个十年内,就可以用它来捕获数据。
05:11
I'm going to show you how we think
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好了,接下来,我将向各位展示,
05:12
it's going to transform our views of the universe,
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LSST将如何改变我们观测宇宙的方式。
05:16
because one image from the LSST
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因为,LSST拍的一张照片,
05:18
is equivalent to 3,000 images
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相当于哈勃望远镜,
05:21
from the Hubble Space Telescope,
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拍摄的3000张图片。
05:23
each image three and a half degrees on the sky,
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每张图片相当于天空的3.5度
05:26
seven times the width of the full moon.
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是满月的7倍宽。
05:29
Well, how do you capture an image at this scale?
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恩,如何才能捕获如此规模的图像呢?
05:31
Well, you build the largest digital camera in history,
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其实,建造这一史上最大望远镜,的技术,
05:35
using the same technology you find in the cameras in your cell phone
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与你的手机摄像头,或者在大街上
05:38
or in the digital cameras you can buy in the High Street,
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可以买到的任何数码相机,所使用的技术一样。
05:42
but now at a scale that is five and a half feet across,
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但是,它的直径是5.5英尺,
05:45
about the size of a Volkswagen Beetle,
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相当于一辆大众甲壳虫的大小,
05:48
where one image is three billion pixels.
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一张图像达到30亿像素,
05:51
So if you wanted to look at an image
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所以,如果你想无损查看
05:52
in its full resolution, just a single LSST image,
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一张LSST图片
05:55
it would take about 1,500 high-definition TV screens.
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大约需要1500块高清电视屏幕。
06:00
And this camera will image the sky,
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而这一望远镜,不间断的扫描天空,
06:03
taking a new picture every 20 seconds,
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以每20秒一张的速度,
06:06
constantly scanning the sky
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环望宇宙。
06:08
so every three nights, we'll get a completely new view
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所以,每过三个夜晚,我们所拍到的智利上方
06:11
of the skies above Chile.
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的天空,都会是一幅全新的景象。
06:13
Over the mission lifetime of this telescope,
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依据这一望远镜的设计寿命,
06:16
it will detect 40 billion stars and galaxies,
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它将可以探测,400亿颗恒星和星系,
06:19
and that will be for the first time
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也将第一次,
06:21
we'll have detected more objects in our universe
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使我们探测到宇宙星体的
06:24
than people on the Earth.
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数量超过地球上人类数量。
06:26
Now, we can talk about this
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然后,我们讨论时,就可以用
06:28
in terms of terabytes and petabytes
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兆和千兆单位,
06:30
and billions of objects,
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以及十亿级个体单位了。
06:31
but a way to get a sense of the amount of data
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为了理解这一望远镜捕获数据 的数量级,
06:33
that will come off this camera
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我们可以这样想象:
06:35
is that it's like playing every TED Talk ever recorded
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这是,你一天24小时,每周7天,
06:40
simultaneously, 24 hours a day,
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连续10年,
06:43
seven days a week, for 10 years.
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同时播放,所有的TED演讲的总和。
06:46
And to process this data means
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而处理这一数据意味着,
06:48
searching through all of those talks
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在所有TED演讲中搜索,
06:50
for every new idea and every new concept,
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新点子和新概念,
06:52
looking at each part of the video
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查并看每个视频的每一部分
06:54
to see how one frame may have changed
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弄清楚每一贞是如何从上一贞
06:56
from the next.
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转换来的。
06:58
And this is changing the way that we do science,
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这将彻底改变我们的科研方式,
07:00
changing the way that we do astronomy,
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并改变我们研究天文学的方式。
07:02
to a place where software and algorithms
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那时,各种软件和算法,
07:05
have to mine through this data,
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将不得不用来挖掘这一数据,
07:07
where the software is as critical to the science
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而软件也变得对科学至关重要,
07:10
as the telescopes and the cameras that we've built.
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同我们建造的望远镜和照相机一样重要。
07:14
Now, thousands of discoveries
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那时,该项目将带来,
07:16
will come from this project,
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成千上万的新发现。
07:18
but I'm just going to tell you about two
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但是,我这里要介绍的,
07:20
of the ideas about origins and evolution
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是这一大数据对我们
07:22
that may be transformed by our access
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关于起源和进化的两个认识,
07:24
to data at this scale.
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将带来的变化。
07:27
In the last five years, NASA has discovered
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过去五年,美国国家航空和宇宙航行局,
07:29
over 1,000 planetary systems
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在附近的恒星周围,
07:32
around nearby stars,
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发现了超过1000个星球体系。
07:34
but the systems we're finding
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但我们发现的这些星系
07:36
aren't much like our own solar system,
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与我们的太阳系不太一样。
07:38
and one of the questions we face is
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而我们提出的一个问题就是,
07:40
is it just that we haven't been looking hard enough
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是我们探测水平有限呢,
07:42
or is there something special or unusual
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还是我们的太阳系就是一个,
07:44
about how our solar system formed?
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特殊和不同寻常的星系呢?
07:46
And if we want to answer that question,
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要解开这一疑问,
07:48
we have to know and understand
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我们需要知道,并理解
07:50
the history of our solar system in detail,
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我们的太阳系的详细历史。
07:53
and it's the details that are crucial.
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而细节将决定我们的成败。
07:55
So now, if we look back at the sky,
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那么,当我们望向
07:59
at our asteroids that were streaming across the sky,
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划过天空的小行星,
08:02
these asteroids are like the debris of our solar system.
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4222
而这些小行星就像太阳系的碎片,
08:06
The positions of the asteroids
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2008
并且,这些小行星的位置,
08:08
are like a fingerprint of an earlier time
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2137
就像宇宙早年留下的指纹。
08:10
when the orbits of Neptune and Jupiter
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1980
那时,海王星和木星
08:12
were much closer to the sun,
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1895
距离太阳还很近,
08:14
and as these giant planets migrated through our solar system,
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而当这些巨型星球在太阳系里迁徙时,
08:18
they were scattering the asteroids in their wake.
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也在他们身后散落下了许多个小行星。
08:21
So studying the asteroids
195
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1306
因此,研究这些小行星,
08:22
is like performing forensics,
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2121
如同在取证一样,
08:25
performing forensics on our solar system,
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-对我们的太阳系进行取证。
08:27
but to do this, we need distance,
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要达到这一目的,我们需要距离,
08:30
and we get the distance from the motion,
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-而距离来自于运动,
08:32
and we get the motion because of our access to time.
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运动来自于我们对时间的控制。
08:36
So what does this tell us?
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那么,这意味着什么呢?
08:38
Well, if you look at the little yellow asteroids
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2227
请注意这些黄色的小行星,
08:40
flitting across the screen,
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高速从屏幕中划过,
08:43
these are the asteroids that are moving fastest,
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这些是移动地最快的小行星,
08:45
because they're closest to us, closest to Earth.
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3341
因为他们离我们最近,离地球最近。
08:48
These are the asteroids we may one day
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有一天,我们也许能够向这些小行星,
08:50
send spacecraft to, to mine them for minerals,
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发送宇宙飞船,从那里采矿。
08:53
but they're also the asteroids that may one day
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2002
但也可能,有一天这些小行星,
08:55
impact the Earth,
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会撞上地球。
08:57
like happened 60 million years ago
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就像6000万年前发生的
08:58
with the extinction of the dinosaurs,
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2635
恐龙灭绝一样,
09:01
or just at the beginning of the last century,
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1822
或者像上世纪初发生的那样:
09:03
when an asteroid wiped out
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1332
一颗小行星落下,
09:04
almost 1,000 square miles of Siberian forest,
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3589
摧毁了西伯利亚1000平方英里的森林。
09:08
or even just last year, as one burnt up over Russia,
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3088
抑或像去年一样,一颗小行星在俄罗斯上空燃尽,
09:11
releasing the energy of a small nuclear bomb.
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3612
释放了一个小型原子弹的能量。
09:14
So studying the forensics of our solar system
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所以,对我们的太阳系进行取证,
09:18
doesn't just tell us about the past,
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2058
并不仅仅是研究过去,
09:20
it can also predict the future, including our future.
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3811
而是要预测未来,包括我们人类的未来。
09:26
Now when we get distance,
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1968
那么,当我们获得距离后,
09:28
we get to see the asteroids in their natural habitat,
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3589
我们将看到这些小行星在原始轨道的样子-
09:32
in orbit around the sun.
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1322
围绕太阳运转时的样子。
09:33
So every point in this visualization that you can see
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2907
所以,你从这一画面中看到的每一个点,
09:36
is a real asteroid.
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2763
都是这些小行星真实所在的位置。
09:39
Its orbit has been calculated from its motion across the sky.
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从它划过天空的运动轨迹,我们计算出它的周转轨道。
09:43
The colors reflect the composition of these asteroids,
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颜色可以反映这些小行星的成分。
09:46
dry and stony in the center,
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2137
中间的干燥多岩石,
09:48
water-rich and primitive towards the edge,
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2587
边缘的富含水分,成分原始,
09:51
water-rich asteroids which may have seeded
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2284
这些富含水分的小行星,
09:53
the oceans and the seas that we find on our planet
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可能正是它们早期撞击地球时
09:57
when they bombarded the Earth at an earlier time.
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为地球带来了海洋的种子。
10:02
Because the LSST will be able to go faint
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LSST不仅能拍摄广域照片,
10:04
and not just wide,
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还能拍摄无光线物体,
10:06
we will be able to see these asteroids
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1808
我们能看到,
10:08
far beyond the inner part of our solar system,
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3187
远离太阳系内圈轨道的小行星,
10:11
to asteroids beyond the orbits of Neptune and Mars,
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3813
离海王星和火星轨道很远的小行星,
10:15
to comets and asteroids that may exist
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2261
以及远离我们的太阳几乎一光年
10:17
almost a light year from our sun.
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3230
的彗星和小行星。
10:20
And as we increase the detail of this picture,
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当我们增加更多的画面细节,
10:23
increasing the detail by factors of 10 to 100,
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3127
将像素从10增加到1000,
10:26
we will be able to answer questions such as,
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我们就能回答类似这样的问题了:
10:29
is there evidence for planets outside the orbit of Neptune,
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3589
有证据证明海王星轨道外存在星球吗?
10:32
to find Earth-impacting asteroids
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2507
能在危机形成前
10:35
long before they're a danger,
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2535
就发现冲向地球的小行星吗?
10:37
and to find out whether, maybe,
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1757
我们的太阳是自成一体的,
10:39
our sun formed on its own or in a cluster of stars,
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3180
并属于恒星之一吗?
10:42
and maybe it's this sun's stellar siblings
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3082
或者,是不是太阳的兄弟姐妹星球
10:45
that influenced the formation of our solar system,
248
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3442
在影响这太阳系的形成?
10:49
and maybe that's one of the reasons why solar systems like ours seem to be so rare.
249
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5753
也许这就是为何我们的太阳系显得如此特殊的原因之一。
10:54
Now, distance and changes in our universe —
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4562
现在,我们来说下宇宙的距离和变化——
10:59
distance equates to time,
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3859
距离相当于时间,
距离相当于天空中的变化。
11:03
as well as changes on the sky.
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2059
11:05
Every foot of distance you look away,
253
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2790
我们望出去的每一尺距离,
11:08
or every foot of distance an object is away,
254
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2485
或者一个物体离去的每一尺距离,
11:10
you're looking back about a billionth of a second in time,
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3589
你看到的都是十亿分之一秒之前的画面。
而这一概念,或者说时间回溯的概念,
11:14
and this idea or this notion of looking back in time
256
674318
2613
11:16
has revolutionized our ideas about the universe,
257
676931
2631
彻底地改变了我们对宇宙的认知。
11:19
not once but multiple times.
258
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2280
不是一次,而是好多次。
11:21
The first time was in 1929,
259
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2812
第一次是在1929年,
11:24
when an astronomer called Edwin Hubble
260
684654
2092
天文学家爱德文·哈勃
11:26
showed that the universe was expanding,
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2249
向人们展示了宇宙是在膨胀的,
11:28
leading to the ideas of the Big Bang.
262
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2713
诞生了宇宙大爆炸的理论。
11:31
And the observations were simple:
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2582
而这一观察是很简单的:
11:34
just 24 galaxies
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2154
仅仅是24个星系
11:36
and a hand-drawn picture.
265
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3050
以及一副手绘图。
但就是这一简单的概念:
11:41
But just the idea that the more distant a galaxy,
266
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4660
“星系离我们越远,其后退的速度越快”,
11:45
the faster it was receding,
267
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2070
11:47
was enough to give rise to modern cosmology.
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3419
就足以开创了现代宇宙学。
11:51
A second revolution happened 70 years later,
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2425
第二次思想变革,发生在70年后,
两组天文学家证明,
11:53
when two groups of astronomers showed
270
713698
2072
11:55
that the universe wasn't just expanding,
271
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2433
宇宙不仅在膨胀,
还在加速。
11:58
it was accelerating,
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1325
这着实让人吃惊,如同我向天空扔出一个球,
11:59
a surprise like throwing up a ball into the sky
273
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3343
但它飞到越高的地方时
12:02
and finding out the higher that it gets,
274
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2812
飞离的速度却越快。
12:05
the faster it moves away.
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1778
他们通过测量超新星的亮度,
12:07
And they showed this
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1509
证实了这一点。
12:08
by measuring the brightness of supernovae,
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2405
同时被证明的还有,超新星的亮度
12:11
and how the brightness of the supernovae
278
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1834
在离我们越远时,变得越暗。
12:13
got fainter with distance.
279
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2171
这些发现就更加复杂了。
12:15
And these observations were more complex.
280
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2453
它们需要新的技术和望远镜,
12:17
They required new technologies and new telescopes,
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3014
因为超新星所在星系的位置
12:20
because the supernovae were in galaxies
282
740847
4050
在哈勃望远镜可观察范围
12:24
that were 2,000 times more distant
283
744897
1958
2000倍以外。
12:26
than the ones used by Hubble.
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746855
2688
12:29
And it took three years to find just 42 supernovae,
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5311
光是发现42颗超新星就花去了3年时间,
12:34
because a supernova only explodes
286
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1754
因为一个星系里的一颗超新星,
12:36
once every hundred years within a galaxy.
287
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3082
每一百年才爆炸一次。
通过搜索上万个星系,
12:39
Three years to find 42 supernovae
288
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2284
才能在3年内发现42颗超新星。
12:41
by searching through tens of thousands of galaxies.
289
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4019
一旦它们收集到了数据,
12:45
And once they'd collected their data,
290
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1851
便将结果汇总为发现。
12:47
this is what they found.
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3748
这虽然看上去并不壮观,
12:51
Now, this may not look impressive,
292
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2711
但这正是它,发生的表面样式。
12:54
but this is what a revolution in physics looks like:
293
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4115
一条可以预测超新星亮度的线,
12:58
a line predicting the brightness of a supernova
294
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2430
距我们110亿光年,
13:00
11 billion light years away,
295
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2046
这条线上还有许多并不甚契合的点。
13:02
and a handful of points that don't quite fit that line.
296
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3796
微小的变化不断汇集,带来了巨变。
13:06
Small changes give rise to big consequences.
297
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4113
通过量变,我们才有了新发现,
13:10
Small changes allow us to make discoveries,
298
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2948
-正如赫歇尔发现天王星一样。
13:13
like the planet found by Herschel.
299
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2823
微小的变化,改变了我们对,
13:16
Small changes turn our understanding
300
796574
2272
宇宙的认识。
13:18
of the universe on its head.
301
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2401
所以,42颗超新星,慢慢地暗去,
13:21
So 42 supernovae, slightly too faint,
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3464
意味着他们正慢慢飞离我们,
13:24
meaning slightly further away,
303
804711
2009
也意味着宇宙不仅在膨胀,
13:26
requiring that a universe must not just be expanding,
304
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3160
而且膨胀的速度还在加快,
13:29
but this expansion must be accelerating,
305
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3330
这揭示了宇宙的一个组成成分,
13:33
revealing a component of our universe
306
813210
1946
我们称之为暗能量,
13:35
which we now call dark energy,
307
815156
2486
这是一种驱动宇宙膨胀的物质,
13:37
a component that drives this expansion
308
817642
2509
占今天宇宙总全部物质的,
13:40
and makes up 68 percent of the energy budget
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3027
68%。
13:43
of our universe today.
310
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2035
13:46
So what is the next revolution likely to be?
311
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3824
那么,下一次思想变革,将会是什么呢?
什么是暗能量,它为什么存在呢?
13:50
Well, what is dark energy and why does it exist?
312
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2719
请看这些线条,每条都代表了,
13:53
Each of these lines shows a different model
313
833294
2328
对暗能量存在形式的不同理论。
13:55
for what dark energy might be,
314
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2843
并描绘暗能量的属性。
13:58
showing the properties of dark energy.
315
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2481
他们与这42个点都存在一致性,
14:00
They all are consistent with the 42 points,
316
840946
3623
但他们背后的理论却
14:04
but the ideas behind these lines
317
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2227
截然不同。
14:06
are dramatically different.
318
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2103
一些人认为,暗能量会
14:08
Some people think about a dark energy
319
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2543
随着时间而变化,
14:11
that changes with time,
320
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1458
或者说,暗能量的成分
14:12
or whether the properties of the dark energy
321
852900
2288
取决于你望向天空时的位置。
14:15
are different depending on where you look on the sky.
322
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2756
另一些人认为,暗能量的变化
14:17
Others make differences and changes
323
857944
1823
存在于亚原子表面。
14:19
to the physics at the sub-atomic level.
324
859767
3048
还有一些人认为,暗能量的变化发生在更大的层面,
14:22
Or, they look at large scales
325
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2790
并改变了重力和广义相对论的作用方式,
14:25
and change how gravity and general relativity work,
326
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3565
或者说,他们认为我们认识的宇宙只是众多宇宙之一,
14:29
or they say our universe is just one of many,
327
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2791
属于神秘的多重宇宙的一部分,
14:31
part of this mysterious multiverse,
328
871961
2598
但是,所有这些概念、理论,
14:34
but all of these ideas, all of these theories,
329
874559
3161
虽然让人吃惊,甚至有些疯狂,
14:37
amazing and admittedly some of them a little crazy,
330
877720
3499
但都与这42个点一致。
14:41
but all of them consistent with our 42 points.
331
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4027
那么,我们如何能在未来十年,
14:45
So how can we hope to make sense of this
332
885246
2182
弄清楚这一问题呢?
14:47
over the next decade?
333
887428
2272
恩,想象一下,如果给你一对骰子,
14:49
Well, imagine if I gave you a pair of dice,
334
889700
3230
然后,你想判断这些骰子,
14:52
and I said you wanted to see whether those dice
335
892930
1999
是否平整。
14:54
were loaded or fair.
336
894929
1867
滚一次骰子,你得到的信息很有限。
14:56
One roll of the dice would tell you very little,
337
896796
2934
但滚越多次,
14:59
but the more times you rolled them,
338
899730
1992
你收集到的信息就越多,
15:01
the more data you collected,
339
901722
1922
你对自己的判断就越有信心。
15:03
the more confident you would become,
340
903644
2172
不仅是这些骰子是否平整,
15:05
not just whether they're loaded or fair,
341
905816
2603
而且是平整的程度,哪里不平整等, 你都了如指掌。
15:08
but by how much, and in what way.
342
908419
3898
我们花费了3年才找到42颗超新星,
15:12
It took three years to find just 42 supernovae
343
912317
3802
是因为我们建造的望远镜,
15:16
because the telescopes that we built
344
916119
3047
只搜索天空的一小部分。
15:19
could only survey a small part of the sky.
345
919166
3693
而当我们建好LSST后,我们每3个夜晚
15:22
With the LSST, we get a completely new view
346
922859
2665
就能获得一幅智力上方天空完整的画面。
15:25
of the skies above Chile every three nights.
347
925524
3622
在LSST运行的第一个晚上,
15:29
In its first night of operation,
348
929146
2463
它发现的超新星数量,就相当于我们发现暗能量,
15:31
it will find 10 times the number of supernovae
349
931609
3150
所需超新星数量的十倍。
15:34
used in the discovery of dark energy.
350
934759
3141
在头4个月内,
15:37
This will increase by 1,000
351
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1809
这一数量将增加到1000倍:
15:39
within the first four months:
352
939709
2493
即最终发现150万颗超新星。
15:42
1.5 million supernovae by the end of its survey,
353
942202
4784
每个超新星代表滚一次骰子,
15:46
each supernova a roll of the dice,
354
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3185
每个超新星能测试一下,
15:50
each supernova testing which theories of dark energy
355
950171
3442
哪种暗能量理论是准确的,哪种是有矛盾的。
15:53
are consistent, and which ones are not.
356
953613
4128
因此,整合这些超新星数据,
15:57
And so, by combining these supernova data
357
957741
3803
结合其他宇宙学方法,
16:01
with other measures of cosmology,
358
961544
2276
我们将排除很大一部分有关暗能量的
16:03
we'll progressively rule out the different ideas
359
963820
2890
假设概念和理论。
16:06
and theories of dark energy
360
966710
1976
如果顺利的话,到2030年,
16:08
until hopefully at the end of this survey around 2030,
361
968686
7142
我们很有希望,能确定一种
16:15
we would expect to hopefully see
362
975828
2614
关于我们宇宙的理论。
16:18
a theory for our universe,
363
978442
2142
一种关于我们宇宙物理现象的根本理论,
16:20
a fundamental theory for the physics of our universe,
364
980584
2539
正在眼前徐徐展开。
16:23
to gradually emerge.
365
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2757
恩,实际上,我刚才所列举的例子,
16:26
Now, in many ways, the questions that I posed
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应该是最简单的问题了。
16:29
are in reality the simplest of questions.
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我们可能不知道答案,
16:33
We may not know the answers,
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但至少知道问题是什么。
16:35
but we at least know how to ask the questions.
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当我们观察上万个星系的时候,
16:39
But if looking through tens of thousands of galaxies
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我们将看到42颗超新星,
16:42
revealed 42 supernovae that turned
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同时对宇宙有更深层次的理解,
16:45
our understanding of the universe on its head,
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如果我们观察上十亿个星系,
16:48
when we're working with billions of galaxies,
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发现的超新星,将是42的多少倍呢?
16:51
how many more times are we going to find
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将与我们的预期有多大出入呢?
16:53
42 points that don't quite match what we expect?
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正如赫歇尔发现的行星(天王星)那样,
16:59
Like the planet found by Herschel
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或者正如暗能量,
17:01
or dark energy
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抑或量子力学,广义相对论那样。
17:04
or quantum mechanics or general relativity,
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所有这些概念都来源于数据,
17:08
all ideas that came because the data
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与我们预期不相符的数据。
17:10
didn't quite match what we expected.
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未来十年的天文学数据,让我们为之欣然鼓舞 而雀跃的,
17:13
What's so exciting about the next decade of data
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将是什么呢?
17:17
in astronomy is,
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我们甚至不知道有多少答案
17:18
we don't even know how many answers
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还在那里等着我们去拾获。
17:21
are out there waiting,
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这是,关于我们起源和进化的答案。
17:22
answers about our origins and our evolution.
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还有许多问题 等我们去提出。
17:26
How many answers are out there
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许多答案,
17:27
that we don't even know the questions
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等待我们去发现。
17:31
that we want to ask?
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谢谢。
17:33
Thank you.
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(掌声)
17:35
(Applause)
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