請雙擊下方英文字幕播放視頻。
譯者: Fred Lee
審譯者: Karen SONG
00:13
So in 1781, an English composer,
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1781 年,一位英國作家、
工程師兼天文學家
00:16
technologist and astronomer called William Herschel
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名叫威廉•赫歇爾,
00:19
noticed an object on the sky that
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在浩瀚的夜空中觀測到一個天體,
00:21
didn't quite move the way the rest of the stars did.
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其運行方式與其他恒星大相徑庭。
00:24
And Herschel's recognition
that something was different,
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赫歇爾覺得這個天體不同尋常,
00:27
that something wasn't quite right,
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有些不太對勁,
00:29
was the discovery of a planet,
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事實上他發現的是一顆行星,
00:31
the planet Uranus,
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也就是我們熟知的天王星。
00:33
a name that has entertained
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天王星這個名字
00:34
countless generations of children,
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讓一代又一代年輕人興趣盎然,
00:37
but a planet that overnight
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然而,這顆高懸於天際的行星
00:40
doubled the size of our known solar system.
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一經發現便讓人類已知的
太陽系範圍整整擴大了一倍。
00:42
Just last month, NASA announced the discovery
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就在上個月,美國太空總署 (NASA)
宣佈其又發現了
00:44
of 517 new planets
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517 顆環繞近地恒星
00:46
in orbit around nearby stars,
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運行的行星,
00:48
almost doubling overnight the number of planets
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幾乎在一夜間使銀河系中
00:51
we know about within our galaxy.
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已知的行星數量翻了一倍。
00:53
So astronomy is constantly being transformed by this
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人類收集的資料資訊
為天文學的不斷進步
00:56
capacity to collect data,
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注入了源源不斷的動力,
00:58
and with data almost doubling every year,
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而這些資料資訊幾乎
以每年翻一倍的速度增長,
01:01
within the next two decades, me may even
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未來二十年內,人類甚至可以
01:02
reach the point for the first time in history
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首次實現有史以來的一個夢想:
01:05
where we've discovered the majority of the galaxies
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探索浩瀚宇宙中
01:08
within the universe.
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的大部分星系。
01:09
But as we enter this era of big data,
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但是,人類開闢的是一個大資料資訊的時代,
01:12
what we're beginning to find is there's a difference
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我們開始探究的是
01:14
between more data being just better
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資料資訊越多越好
01:17
and more data being different,
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與資料資訊越多差別越大,
兩者之間有何差異,
01:19
capable of changing the questions we want to ask,
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這足以改變我們想問的一些問題,
01:22
and this difference is not about
how much data we collect,
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這個差異並不在於我們收集多少資料資訊,
01:25
it's whether those data open new windows
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而是,那些資料資訊是否可以
為人類開啟一扇通往深邃宇宙的窗戶,
01:27
into our universe,
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01:28
whether they change the way we view the sky.
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那些資料資訊是否有助於
改變人類對觀測天空的方式。
01:31
So what is the next window into our universe?
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下一扇通往宇宙的窗戶會有何奧秘呢?
01:34
What is the next chapter for astronomy?
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人類將如何譜寫天文學的下一個篇章?
01:37
Well, I'm going to show you some
of the tools and the technologies
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好,我會向諸位介紹一下
01:40
that we're going to develop over the next decade,
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未來十年內人類將開發的一些工具與技術,
01:42
and how these technologies,
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這些先進技術,連同人類
01:44
together with the smart use of data,
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在運用資料資訊上展現的聰明才智,
01:46
may once again transform astronomy
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將再一次開啟一扇通往宇宙的窗戶
01:49
by opening up a window into our universe,
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使天文學發生革命性的變化,
01:51
the window of time.
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時間之窗。
01:53
Why time? Well, time is about origins,
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為什麼是時間?好,時間與起源
01:55
and it's about evolution.
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和進化息息相關。
01:57
The origins of our solar system,
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太陽系的起源、
01:58
how our solar system came into being,
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太陽系是如何形成的、
02:01
is it unusual or special in any way?
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有什麼不同尋常或獨特之處嗎?
02:04
About the evolution of our universe.
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關於宇宙的演化。
02:06
Why our universe is continuing to expand,
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為什麼宇宙處於不斷的膨脹中?
02:09
and what is this mysterious dark energy
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促使宇宙膨脹的
02:11
that drives that expansion?
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神秘暗能量是什麼呢?
02:14
But first, I want to show you how technology
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首先,我要向諸位介紹科學技術
02:16
is going to change the way we view the sky.
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將有望改變人類對觀測天空的方式。
02:19
So imagine if you were sitting
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不妨設想一下,如果你在
02:21
in the mountains of northern Chile
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智利北部山區
02:23
looking out to the west
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仰望西天,
02:24
towards the Pacific Ocean
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面向太平洋方向,
02:26
a few hours before sunrise.
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就在日出前幾個小時。
02:29
This is the view of the night sky that you would see,
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這便是你將親眼目睹的夜空,
02:32
and it's a beautiful view,
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景色美麗動人,
02:34
with the Milky Way just peeking out over the horizon.
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銀河懸掛於天際。
02:37
but it's also a static view,
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但眼前是一幅靜止的美景,
02:39
and in many ways, this is the
way we think of our universe:
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而很多時候這也正是
我們腦海中勾勒出的宇宙:
02:42
eternal and unchanging.
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永恆不滅且一成不變。
02:44
But the universe is anything but static.
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但宇宙絕不是靜止的。
02:46
It constantly changes on timescales of seconds
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宇宙處於永恆的變化中,
變化時間各不相同
02:48
to billions of years.
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有短短幾秒,也有幾十億年。
02:50
Galaxies merge, they collide
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不同的星系
02:52
at hundreds of thousands of miles per hour.
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在以幾十萬英里的時速融合、碰撞。
02:55
Stars are born, they die,
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恒星不斷誕生,也不斷消亡,
02:57
they explode in these extravagant displays.
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這些絢麗多彩的畫面展示了恒星的爆炸。
03:00
In fact, if we could go back
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事實上,如果可以回到
03:01
to our tranquil skies above Chile,
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智利遙望寧靜的夜空,
03:04
and we allow time to move forward
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我們讓時間長河向前流淌
03:06
to see how the sky might change over the next year,
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一覽未來十年的天空,
會呈現出什麼模樣,
03:11
the pulsations that you see
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你會觀察到宇宙的脈動
03:13
are supernovae, the final remnants of a dying star
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正是超新星,恒星在消亡中留下的殘餘,
03:17
exploding, brightening and then fading from view,
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爆炸、發出耀眼的光芒,
然後逐漸消失在視野中,
03:21
each one of these supernovae
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任何一顆超新星
03:23
five billion times the brightness of our sun,
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都比太陽亮上五十億倍,
03:26
so we can see them to great distances
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因此,人類在相當遙遠的地方
就能發現它們的蹤跡
03:28
but only for a short amount of time.
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但其光芒轉瞬即逝。
03:31
Ten supernova per second explode somewhere
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宇宙中每一秒都會
有十顆超新星發生爆炸。
03:33
in our universe.
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03:35
If we could hear it,
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如果我們可以聽見爆炸聲,
03:36
it would be popping like a bag of popcorn.
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會同一袋爆米花爆開的聲音一樣。
03:40
Now, if we fade out the supernovae,
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超新星的光芒逐漸暗淡,
03:43
it's not just brightness that changes.
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這不只是亮度的變化。
03:46
Our sky is in constant motion.
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天空處於永恆的運動之中。
03:49
This swarm of objects you
see streaming across the sky
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你會看到大量天體源源不斷地掠過天空
03:52
are asteroids as they orbit our sun,
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這些是環繞太陽運行的小行星,
03:54
and it's these changes and the motion
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正是這些變化與運動
03:56
and it's the dynamics of the system
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以及天體系統的動態變化
03:59
that allow us to build our models for our universe,
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讓我們得以創建宇宙的模型,
04:01
to predict its future and to explain its past.
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便於我們解讀過去,展望未來。
04:05
But the telescopes we've used over the last decade
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然而,過去十年裡,我們使用的望遠鏡
04:08
are not designed to capture the data at this scale.
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其設計初衷並非用於
收集如此大規模的資料資訊。
04:12
The Hubble Space Telescope:
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哈伯太空望遠鏡:
04:14
for the last 25 years it's been producing
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在過去二十五年內,
04:16
some of the most detailed views
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已為人類生成了部分宇宙深處
04:18
of our distant universe,
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最生動具體的畫面,
04:20
but if you tried to use the Hubble to create an image
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不過,若要使用哈伯太空望遠鏡
去還原一幅天空全景圖,
04:22
of the sky, it would take 13 million individual images,
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則需要彙聚 1300 萬個獨立的景象,
04:27
about 120 years to do this just once.
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即使一次也得歷時 120 年之久。
04:30
So this is driving us to new technologies
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面對這一形勢,我們必須開發新技術
04:33
and new telescopes,
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並建造全新的望遠鏡,
04:35
telescopes that can go faint
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這些望遠鏡不僅觀測距離更遠,
04:36
to look at the distant universe
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讓人類深入宇宙腹地。
04:38
but also telescopes that can go wide
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而且觀測視野更寬,
04:41
to capture the sky as rapidly as possible,
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可迅速拍攝天空中的一舉一動,
04:43
telescopes like the Large Synoptic Survey Telescope,
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像大口徑全景巡天望遠鏡之類的望遠鏡
04:47
or the LSST,
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又稱為 LSST。
04:49
possibly the most boring name ever
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縱觀天文學歷史,
04:51
for one of the most fascinating experiments
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在所有最有趣的科學實驗中
04:53
in the history of astronomy,
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這個名稱算是最最無聊的,
04:55
in fact proof, if you should need it,
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事實上,你如果非得有個名稱,
04:57
that you should never allow
a scientist or an engineer
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那千萬別讓科學家或工程師來命名,
05:00
to name anything, not even your children.
(Laughter)
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甚至不要讓他們為你的孩子起名字。(笑聲)
05:06
We're building the LSST.
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LSST 工程已開工建設。
05:07
We expect it to start taking data
by the end of this decade.
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有望於2020年年底前開始收集資料資訊。
05:11
I'm going to show you how we think
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我將為諸位解讀一下我們的思維方式
05:12
it's going to transform
our views of the universe,
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這將轉變我們對宇宙的認識,
05:16
because one image from the LSST
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因為 LSST 拍攝的每個圖像
05:18
is equivalent to 3,000 images
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相當於哈伯太空望遠鏡拍攝的 3000 個圖像,
05:21
from the Hubble Space Telescope,
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05:23
each image three and a half degrees on the sky,
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LSST 的每個圖像覆蓋了天空中 3.5 度的區域,
05:26
seven times the width of the full moon.
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相當於七個滿月的寬度。
05:29
Well, how do you capture an image at this scale?
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如何拍攝這麼大的圖像呢?
05:31
Well, you build the largest digital camera in history,
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那就得製造有史以來最大的數位相機,
05:35
using the same technology you find
in the cameras in your cell phone
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採用的技術與你的手機鏡頭
05:38
or in the digital cameras you
can buy in the High Street,
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或在大街上購買的數位相機
採用的技術完全相同,
05:42
but now at a scale that is five and a half feet across,
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而眼下這個數位相機的鏡頭
足足寬5.5英尺,
05:45
about the size of a Volkswagen Beetle,
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相當於一輛福斯金龜車的長度,
05:48
where one image is three billion pixels.
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這個鏡頭拍攝的每個圖像
有30億個圖元。
05:51
So if you wanted to look at an image
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因此,如果你想一睹
LSST 全解析度圖像的風采,
05:52
in its full resolution, just a single LSST image,
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哪怕只是一個圖像,
05:55
it would take about 1,500
high-definition TV screens.
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也得用 1500 個高清電視螢幕。
06:00
And this camera will image the sky,
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這台相機將用於拍攝天空的全景,
06:03
taking a new picture every 20 seconds,
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每隔 20 秒鐘拍攝一張照片,
06:06
constantly scanning the sky
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永不停息地掃描天空。
06:08
so every three nights, we'll get a completely new view
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這樣只要三個夜晚,
我們就能掃描一次天空,
06:11
of the skies above Chile.
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重新繪製一幅智利上空的天空全景圖。
06:13
Over the mission lifetime of this telescope,
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這台望遠鏡會在其生命週期內
06:16
it will detect 40 billion stars and galaxies,
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探測 400 億恒星與星系,
06:19
and that will be for the first time
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這也會是我們首次
06:21
we'll have detected more objects in our universe
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能探索的宇宙天體數量
06:24
than people on the Earth.
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超過地球上的人口數。
06:26
Now, we can talk about this
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目前,我們可以按
06:28
in terms of terabytes and petabytes
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百萬位元組與十億位元組,
通過研究數十億個天體
06:30
and billions of objects,
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來解讀宇宙,
06:31
but a way to get a sense of the amount of data
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但如果想要親身感受一下
06:33
that will come off this camera
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這款相機收集的訊息量,
06:35
is that it's like playing every TED Talk ever recorded
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好比同時播放已錄製的每一個 TED 演講,
06:40
simultaneously, 24 hours a day,
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一天二十四小時,
06:43
seven days a week, for 10 years.
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一周七天不停地播放,可以長達連續十年。
06:46
And to process this data means
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若要處理這些資料資訊,則如同
06:48
searching through all of those talks
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在所有訪談節目中搜索
06:50
for every new idea and every new concept,
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每一個全新的觀點與理念,
06:52
looking at each part of the video
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關注影片中的每個細節。
06:54
to see how one frame may have changed
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查看每一幀內容
06:56
from the next.
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有何變化。
06:58
And this is changing the way that we do science,
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我們正在開闢一個科學研究的新紀元,
07:00
changing the way that we do astronomy,
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顛覆天文學研究的傳統模式,
07:02
to a place where software and algorithms
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在全新的模式下人們
將運用軟體技術與演算法則
07:05
have to mine through this data,
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挖掘隱藏在資料資訊中的無窮奧秘,
07:07
where the software is as critical to the science
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屆時軟體技術對科學研究至關重要,
07:10
as the telescopes and the
cameras that we've built.
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其重要性並不亞於這些
尚未問世的望遠鏡與相機。
07:14
Now, thousands of discoveries
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目前,這個專案將為人類
07:16
will come from this project,
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開啟成千上萬的探索發現之門,
07:18
but I'm just going to tell you about two
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但我今天只向諸位講述
07:20
of the ideas about origins and evolution
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有關起源與進化的兩個理念
07:22
that may be transformed by our access
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這兩個理念也會隨著人們
07:24
to data at this scale.
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對大規模資料資訊的研究而不斷發展。
07:27
In the last five years, NASA has discovered
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過去五年內,NASA 已在近地恒星
07:29
over 1,000 planetary systems
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附近發現了 1000 多個行星系,
07:32
around nearby stars,
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07:34
but the systems we're finding
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但我們力求探尋的這些行星系
07:36
aren't much like our own solar system,
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並不十分類似於我們的太陽系。
07:38
and one of the questions we face is
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我們面臨的一個問題是
07:40
is it just that we haven't been looking hard enough
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究竟是人類對宇宙的觀測還不夠全面,
07:42
or is there something special or unusual
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還是我們太陽系的起源
07:44
about how our solar system formed?
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本來就與眾不同?
07:46
And if we want to answer that question,
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如果我們要解答這一問題,
07:48
we have to know and understand
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就得深入瞭解
07:50
the history of our solar system in detail,
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太陽系的前世與今生,
07:53
and it's the details that are crucial.
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這些具體資訊十分重要。
07:55
So now, if we look back at the sky,
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因此,時下當我們仰望星空,
07:59
at our asteroids that were streaming across the sky,
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無數小行星掠過天際,
08:02
these asteroids are like the
debris of our solar system.
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彷彿是太陽系中遺落的殘骸。
08:06
The positions of the asteroids
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小行星所處的位置
08:08
are like a fingerprint of an earlier time
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2137
就像海王星與木星早期運行軌道,
08:10
when the orbits of Neptune and Jupiter
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1980
離太陽更近的時候在
08:12
were much closer to the sun,
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宇宙中留下的指紋,
08:14
and as these giant planets migrated
through our solar system,
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這些體積巨大的行星在太陽系中遷徙,
08:18
they were scattering the asteroids in their wake.
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一路遺落不計其數的小行星。
08:21
So studying the asteroids
195
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因此,探究小行星就像
08:22
is like performing forensics,
196
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2121
在進行法醫鑒定,
08:25
performing forensics on our solar system,
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對整個太陽系的法醫鑒定。
08:27
but to do this, we need distance,
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但為此,我們需要距離,
08:30
and we get the distance from the motion,
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通過天體的運行,可以得知距離,
08:32
and we get the motion because of our access to time.
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而由於對時間掌握,
我們才瞭解了天體的運行。
08:36
So what does this tell us?
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我們可以從中得到什麼啟示呢?
08:38
Well, if you look at the little yellow asteroids
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2227
你是否注意到一些黃色小行星
08:40
flitting across the screen,
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2273
匆匆掠過螢幕,
08:43
these are the asteroids that are moving fastest,
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這些小行星的運行速度很快,
08:45
because they're closest to us, closest to Earth.
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3341
是因為它們距離地球最近。
08:48
These are the asteroids we may one day
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1507
有朝一日人類或許會派
太空船造訪這些行星
08:50
send spacecraft to, to mine them for minerals,
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開發上面的礦產資源,
08:53
but they're also the asteroids that may one day
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2002
但這些小行星或許會在未來的某一天
08:55
impact the Earth,
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撞擊地球,
08:57
like happened 60 million years ago
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就像 6000 萬年前的那次撞擊
08:58
with the extinction of the dinosaurs,
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2635
造成了恐龍的滅絕,
09:01
or just at the beginning of the last century,
212
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1822
也像上世紀初葉
09:03
when an asteroid wiped out
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1332
一顆小行星徑直墜落於西伯利亞,
09:04
almost 1,000 square miles of Siberian forest,
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1000 平方英里的森林頓時化為烏有,
09:08
or even just last year, as one burnt up over Russia,
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3088
甚至就在去年,有一顆小行星
在俄羅斯上空的大氣層內燒毀,
09:11
releasing the energy of a small nuclear bomb.
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3612
釋放的能量相當於一個小型核彈。
09:14
So studying the forensics of our solar system
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因此,對太陽系進行法醫鑒定
09:18
doesn't just tell us about the past,
218
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2058
不只能讓我們瞭解過去,
09:20
it can also predict the future,
including our future.
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更可以展望未來,包括人類自身的未來。
09:26
Now when we get distance,
220
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1968
眼下只要我們得知距離,
09:28
we get to see the asteroids
in their natural habitat,
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3589
就能觀察到小行星以其自然的方式,
09:32
in orbit around the sun.
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1322
環繞太陽運行。
09:33
So every point in this visualization that you can see
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所以,諸位在這幅景象中
看到的每一個亮點
09:36
is a real asteroid.
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都是一顆真實的小行星。
09:39
Its orbit has been calculated
from its motion across the sky.
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4010
憑藉這顆小行星在空中的運行狀況,
就能計算出其運行軌跡。
09:43
The colors reflect the composition of these asteroids,
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3341
這些小行星的顏色顯示了其組成物質,
09:46
dry and stony in the center,
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2137
中心部分是乾燥的岩石,
09:48
water-rich and primitive towards the edge,
228
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2587
而表面卻粗糙不平,富含水分,
09:51
water-rich asteroids which may have seeded
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2284
含水量較高的小新星上可能會有
09:53
the oceans and the seas that we find on our planet
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3451
和地球上一模一樣的海洋,
09:57
when they bombarded the
Earth at an earlier time.
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3206
地球上的海洋正是小行星
早年撞擊地球後留下的。
10:02
Because the LSST will be able to go faint
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2832
由於 LSST 不僅觀察視野更寬,
10:04
and not just wide,
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而且探測距離更遠。
10:06
we will be able to see these asteroids
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1808
我們將在遠離太陽系中心的區域
10:08
far beyond the inner part of our solar system,
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3187
一窺這些小行星的身影,
10:11
to asteroids beyond the
orbits of Neptune and Mars,
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3813
觀察木星與火星軌道之外的小行星,
10:15
to comets and asteroids that may exist
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2261
跟蹤距離太陽
10:17
almost a light year from our sun.
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幾乎一光年之遙的彗星與小行星。
10:20
And as we increase the detail of this picture,
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我們會更加詳細地解讀這些照片
10:23
increasing the detail by factors of 10 to 100,
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將解讀細節從 10 個提高到 100 個,
10:26
we will be able to answer questions such as,
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2430
就能找到一些問題的答案,例如
10:29
is there evidence for planets
outside the orbit of Neptune,
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3589
是否有證據顯示木星軌道之外還存在行星,
10:32
to find Earth-impacting asteroids
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2507
在可能撞擊地球的小行星威脅地球之前很久
10:35
long before they're a danger,
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2535
便鎖定它們的行蹤,
10:37
and to find out whether, maybe,
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1757
並解答太陽只有一個
10:39
our sun formed on its own or in a cluster of stars,
246
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3180
還是宇宙中存在一大把這樣的恒星,
10:42
and maybe it's this sun's stellar siblings
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3082
或許正是太陽的姊妹星
10:45
that influenced the formation of our solar system,
248
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3442
對太陽系的形成產生了巨大的影響,
10:49
and maybe that's one of the reasons why
solar systems like ours seem to be so rare.
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5753
或許這正是太陽系在宇宙中
如此罕見的原因之一。
10:54
Now, distance and changes in our universe —
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4562
宇宙中的距離與變化,
10:59
distance equates to time,
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3859
距離等於時間,
11:03
as well as changes on the sky.
252
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2059
以及天空中的變化。
11:05
Every foot of distance you look away,
253
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2790
你的目光每延伸一英尺
11:08
or every foot of distance an object is away,
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2485
或某一個天體運行每一英尺,
11:10
you're looking back about a
billionth of a second in time,
255
670729
3589
其實在諸位眼睛中留下的景象
是之前十億分之一秒發生的事情,
11:14
and this idea or this notion of looking back in time
256
674318
2613
眺望宇宙就是眺望過去的時光
11:16
has revolutionized our ideas about the universe,
257
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2631
這個觀點或概念讓我們
對宇宙的認識發生了革命性的變化,
11:19
not once but multiple times.
258
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2280
這種變化不止一次,而是多次。
11:21
The first time was in 1929,
259
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2812
第一次發生在 1929 年,
11:24
when an astronomer called Edwin Hubble
260
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2092
一位名叫愛德文·哈伯的天文學家
11:26
showed that the universe was expanding,
261
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2249
指出宇宙處在不斷的膨脹中,
11:28
leading to the ideas of the Big Bang.
262
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2713
形成了宇宙大爆炸觀點。
11:31
And the observations were simple:
263
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2582
觀察結果非常簡單:
11:34
just 24 galaxies
264
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2154
只有 24 個星系
11:36
and a hand-drawn picture.
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3050
和一張手工繪製的圖片。
11:41
But just the idea that the more distant a galaxy,
266
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4660
但星系的距離越遠,
11:45
the faster it was receding,
267
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2070
它遠離我們的速度就越快,
11:47
was enough to give rise to modern cosmology.
268
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3419
這一觀點足以促成現代宇宙學的誕生。
11:51
A second revolution happened 70 years later,
269
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2425
第二次革命發生在 70 年後,
11:53
when two groups of astronomers showed
270
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2072
兩組天文學家指出
11:55
that the universe wasn't just expanding,
271
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2433
宇宙不僅在不斷地膨脹,
11:58
it was accelerating,
272
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1325
而且正在加速膨脹。
11:59
a surprise like throwing up a ball into the sky
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3343
這個觀點令人驚訝,
好比將一個球拋到空中,
12:02
and finding out the higher that it gets,
274
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2812
你會發現這個球離地面越高,
12:05
the faster it moves away.
275
725683
1778
飛行的速度也越快。
12:07
And they showed this
276
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1509
他們展示研究結果的方法是
12:08
by measuring the brightness of supernovae,
277
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2405
通過測量超新星的亮度,
12:11
and how the brightness of the supernovae
278
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1834
和超新星的亮度
12:13
got fainter with distance.
279
733209
2171
如何隨著距離增加而不斷減弱。
12:15
And these observations were more complex.
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2453
這些觀察結果更加複雜。
12:17
They required new technologies and new telescopes,
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3014
於是新技術與全新的望遠鏡呼之欲出,
12:20
because the supernovae were in galaxies
282
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4050
由於超新星存在於一些星系中
12:24
that were 2,000 times more distant
283
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1958
而這些星系比哈伯望遠鏡
12:26
than the ones used by Hubble.
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746855
2688
拍攝到的星系還要遠 2000 倍。
12:29
And it took three years to find just 42 supernovae,
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5311
經過三年鍥而不捨的觀察,
只發現了 42 顆超新星,
12:34
because a supernova only explodes
286
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1754
由於一個星系中的超新星
12:36
once every hundred years within a galaxy.
287
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3082
幾百年中才爆炸一次。
12:39
Three years to find 42 supernovae
288
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2284
整整三年才發現了 42 顆超新星,
12:41
by searching through tens of thousands of galaxies.
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4019
搜索了成千上萬個星系。
12:45
And once they'd collected their data,
290
765993
1851
收集了這些資料資訊,
12:47
this is what they found.
291
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3748
這是他們發現的。
12:51
Now, this may not look impressive,
292
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2711
這一研究成果可能看上去不起眼,
12:54
but this is what a revolution in physics looks like:
293
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4115
但可以堪稱物理學上的一次革命:
12:58
a line predicting the brightness of a supernova
294
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2430
這條直線預測距離地球
110 億光年之遙的超新星亮度,
13:00
11 billion light years away,
295
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2046
13:02
and a handful of points that don't quite fit that line.
296
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3796
一些小點與這條直線並不十分吻合。
13:06
Small changes give rise to big consequences.
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4113
細微的變化往往會催生重大結果。
13:10
Small changes allow us to make discoveries,
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2948
細微的變化讓我們實現突破,探索發現,
13:13
like the planet found by Herschel.
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2823
就像赫歇爾當年發現天王星一樣。
13:16
Small changes turn our understanding
300
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2272
細微的變化顛覆了
13:18
of the universe on its head.
301
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2401
我們對浩瀚宇宙的理解。
13:21
So 42 supernovae, slightly too faint,
302
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3464
因此,42 顆超新星,十分昏暗,
13:24
meaning slightly further away,
303
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2009
可見其距離地球稍遠,
13:26
requiring that a universe must not just be expanding,
304
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3160
由此可推斷宇宙肯定不只是在膨脹,
13:29
but this expansion must be accelerating,
305
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3330
而是在加速膨脹。
13:33
revealing a component of our universe
306
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1946
揭示了宇宙的一個組成部分
13:35
which we now call dark energy,
307
815156
2486
就是我們目前所稱的暗能量,
13:37
a component that drives this expansion
308
817642
2509
正是暗能量在加速宇宙的膨脹,
13:40
and makes up 68 percent of the energy budget
309
820151
3027
已知宇宙中的能量預計有68%為暗能量。
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
下一次革命可能會發生在哪個領域?
13:50
Well, what is dark energy and why does it exist?
312
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2719
暗能量是什麼,暗能量為什麼會存在?
13:53
Each of these lines shows a different model
313
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2328
每一條直線為我們展現了
13:55
for what dark energy might be,
314
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2843
一種不同的暗能量可能存在的模式
13:58
showing the properties of dark energy.
315
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2481
揭示了暗能量的各種屬性。
14:00
They all are consistent with the 42 points,
316
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3623
已發現的 42 個亮點完全符合這些屬性,
14:04
but the ideas behind these lines
317
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2227
但隱藏在這些直線背後的理念
14:06
are dramatically different.
318
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2103
則截然不同。
14:08
Some people think about a dark energy
319
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2543
有人設想暗能量
14:11
that changes with time,
320
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1458
隨著時間的流逝而變化,
14:12
or whether the properties of the dark energy
321
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2288
或是暗能量的屬性是否不同,
14:15
are different depending on where you look on the sky.
322
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2756
取決於你觀察天空時所處的地點。
14:17
Others make differences and changes
323
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1823
其他人則在亞原子的層面
14:19
to the physics at the sub-atomic level.
324
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3048
釐定物理學上的差異與變化。
14:22
Or, they look at large scales
325
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2790
或者,他們關注
14:25
and change how gravity and general relativity work,
326
865605
3565
重力與廣義相對論作用的規模與變化,
14:29
or they say our universe is just one of many,
327
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2791
或他們覺得我們的宇宙只是
14:31
part of this mysterious multiverse,
328
871961
2598
這個神秘莫測的多元宇宙中的一部分而已,
14:34
but all of these ideas, all of these theories,
329
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3161
但是所有這些觀點、理論
14:37
amazing and admittedly some of them a little crazy,
330
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3499
非常不可思議,毋庸置疑
其中一些稍稍有些瘋狂,
14:41
but all of them consistent with our 42 points.
331
881219
4027
但所有這些觀點與理論
都於我們發現的 42 個亮點相互印證。
14:45
So how can we hope to make sense of this
332
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2182
因此,我們如何在未來十年內
14:47
over the next decade?
333
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2272
理解其中的奧秘?
14:49
Well, imagine if I gave you a pair of dice,
334
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3230
設想一下,如果給你兩個骰子,
14:52
and I said you wanted to see whether those dice
335
892930
1999
我問你如何知道這兩個骰子
14:54
were loaded or fair.
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894929
1867
是不是被人做了手腳。
14:56
One roll of the dice would tell you very little,
337
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2934
只投一次骰子,你得不出什麼結論,
14:59
but the more times you rolled them,
338
899730
1992
但多投幾次,
15:01
the more data you collected,
339
901722
1922
積攢起數據,
15:03
the more confident you would become,
340
903644
2172
就會對自己更有信心,
15:05
not just whether they're loaded or fair,
341
905816
2603
不僅知道這些骰子
有沒有被人做過手腳,
15:08
but by how much, and in what way.
342
908419
3898
而且還知道做了多少手腳,
而且怎麼做的。
15:12
It took three years to find just 42 supernovae
343
912317
3802
我們歷時整整三年
才發現了 42 個超新星,
15:16
because the telescopes that we built
344
916119
3047
因為我們已建造的望遠鏡
15:19
could only survey a small part of the sky.
345
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3693
只能探索天空中的很小一部分。
15:22
With the LSST, we get a completely new view
346
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2665
有了 LSST,每三個夜晚我們就可以觀察到
15:25
of the skies above Chile every three nights.
347
925524
3622
智利上空的一個全新景象。
15:29
In its first night of operation,
348
929146
2463
觀測的第一個夜晚,
15:31
it will find 10 times the number of supernovae
349
931609
3150
發現的超新星的數量,
就會是當初發現暗能量時
15:34
used in the discovery of dark energy.
350
934759
3141
所用的超新星數量的整整十倍。
15:37
This will increase by 1,000
351
937900
1809
最初的四個月內的觀測數字將提升 1000:
15:39
within the first four months:
352
939709
2493
15:42
1.5 million supernovae by the end of its survey,
353
942202
4784
這次觀察後會發現 150 萬顆超新星,
15:46
each supernova a roll of the dice,
354
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3185
每一顆超新星就像投一次骰子
15:50
each supernova testing which theories of dark energy
355
950171
3442
每一個超新星測試哪些暗能量理論吻合,
15:53
are consistent, and which ones are not.
356
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4128
哪些不吻合。
15:57
And so, by combining these supernova data
357
957741
3803
所以,這些超新星資料資訊會
16:01
with other measures of cosmology,
358
961544
2276
與宇宙學的其他措施相結合,
16:03
we'll progressively rule out the different ideas
359
963820
2890
我們會逐步篩除
不同的暗能量觀點與理論,
16:06
and theories of dark energy
360
966710
1976
16:08
until hopefully at the end of this survey around 2030,
361
968686
7142
此次觀察有望在 2030 年左右結束,
16:15
we would expect to hopefully see
362
975828
2614
我們希望屆時發現
16:18
a theory for our universe,
363
978442
2142
一種宇宙理論,
16:20
a fundamental theory for the physics of our universe,
364
980584
2539
一種宇宙物理的基本理論
16:23
to gradually emerge.
365
983123
2757
漸漸顯出雛形。
16:26
Now, in many ways, the questions that I posed
366
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2392
我在許多領域提出過一些問題
16:29
are in reality the simplest of questions.
367
989342
4361
實際上都是最簡單的問題。
16:33
We may not know the answers,
368
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1754
但答案至今無從知曉,
16:35
but we at least know how to ask the questions.
369
995457
3852
但我們至少知道該如何提問。
16:39
But if looking through tens of thousands of galaxies
370
999309
3118
但是如果縱觀成千上萬個星系
16:42
revealed 42 supernovae that turned
371
1002427
2938
結果只發現了 42 顆超新星,
16:45
our understanding of the universe on its head,
372
1005365
3479
足以轉變我們對茫茫宇宙的理解,
16:48
when we're working with billions of galaxies,
373
1008844
2914
當我們專注於研究數十億星系,
16:51
how many more times are we going to find
374
1011758
1777
我們費盡周折只發現了 42 個亮點,
這顯然不符合我們的期望值,
16:53
42 points that don't quite match what we expect?
375
1013535
5648
但這樣事倍功半的事情還會發生多少次呢?
16:59
Like the planet found by Herschel
376
1019183
2757
就像赫歇爾發現天王星
17:01
or dark energy
377
1021940
2417
或暗能量,
17:04
or quantum mechanics or general relativity,
378
1024357
3843
或量子力學或廣義相對論,
17:08
all ideas that came because the data
379
1028200
2344
這些理論的產生,都是因為資訊
17:10
didn't quite match what we expected.
380
1030544
3455
並不符合我們的期望,
17:13
What's so exciting about the next decade of data
381
1033999
3261
天文學資訊的下一個十年
17:17
in astronomy is,
382
1037260
1670
激動人心的一面正是
17:18
we don't even know how many answers
383
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2211
我們甚至不知道會有多少問題
17:21
are out there waiting,
384
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1800
等待著我們去解答,
17:22
answers about our origins and our evolution.
385
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3881
這些解答關乎宇宙起源與演化。
17:26
How many answers are out there
386
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1095
還有多少解答已經擺在面前,
17:27
that we don't even know the questions
387
1047917
3294
但我們甚至不知道
17:31
that we want to ask?
388
1051211
2011
要問些什麼?
17:33
Thank you.
389
1053222
1947
謝謝。
17:35
(Applause)
390
1055169
3702
(掌聲)
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