ABOUT THE SPEAKER
Natasha Hurley-Walker - Astronomer
Natasha Hurley-Walker uses novel radio telescopes to explore the universe at some of the longest wavelengths of light.

Why you should listen

Dr. Natasha Hurley-Walker recently completed an astronomical survey of the entire southern sky, revealing the radio glow of our own Milky Way galaxy as well as hundreds of thousands of distant galaxies: the GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey. Unlike previous work, GLEAM is the first "radio color" survey, observed across such a wide range of frequencies that the unique spectrum of every object can be used to understand its underlying physics.

An Early-Career Research Fellow based at the Curtin University node of the International Centre for Radio Astronomy Research, in Perth, Western Australia, Hurley-Walker is part of the international Murchison Widefield Array (MWA) collaboration, spanning thirteen institutes across six countries. At her fingertips are tens of petabytes of data collected by the MWA since 2013, which she processes using powerful supercomputers at the nearby Pawsey Centre. Hurley-Walker earned a PhD in Radio Astronomy at the University of Cambridge by commissioning and using a new radio telescope to perform its first science observations. The experience directly transferred to the MWA, which she also helped to commission.

The MWA is a precursor to the Square Kilometer Array (SKA), what will be the largest radio telescope in the world, set to come online in the 2020s. By developing software and techniques to deal with data from the MWA, creating pathfinding maps of the sky and training a new generation of astronomers in cutting-edge techniques, Hurley-Walker is working to lay the scientific groundwork for the commissioning of the SKA. In 2016 Hurley-Walker was awarded an Australian SKA Fellowship in order to visit the SKA headquarters and transfer lessons from her commissioning experiences as well as develop her survey into a useful calibration model for the SKA.

Hurley-Walker is passionate about scientific outreach and keynoted talks in 2013 and 2017 at Astrofest, Australia's largest public astronomy festival. So that anyone in the world can see the sky with the same radio eyes as her, she created the GLEAMoscope , an interactive online viewer that shows the universe at radio wavelengths compared to other frequencies, including the more familiar "optical" spectrum. It being the 21st century, there's also an app: check out GLEAM on the Google Play store. In 2017 Natasha won the "Best Timelapse" category in the Astofest astrophotography competition with her colleague John Goldsmith for their creation of a composite video showing both the optical and radio sky. For more detail on Hurley-Walker's work, check out her article on TheConversation.

Working with cutting-edge data is tough, but sometimes hides serendipitous gems which Hurley-Walker has unearthed, like the faintest dying radio galaxy ever discoveredwhistling plasma ducts in the Earth's ionosphere and some of the youngest and weirdest radio galaxies ever found. View a complete list of Hurley-Walker's publications.

More profile about the speaker
Natasha Hurley-Walker | Speaker | TED.com
TEDxPerth

Natasha Hurley-Walker: How radio telescopes show us unseen galaxies

娜塔莎 赫莉-沃克: 射电望远镜是怎样给我们展示肉眼见不到的宇宙的

Filmed:
1,295,837 views

宇航员娜塔莎 赫莉-沃克说,我们的宇宙是奇妙的,壮观的,苍茫的,广阔的。现在宇宙飞船还不能带你探究宇宙的深处——但是,一个射电望远镜可以。在这个吸引人的,充满想象的演讲中,Hurley-Walker给我们展示了她是怎样使用特殊的科技展示我们看不见的光谱来探索宇宙的奥秘的。
- Astronomer
Natasha Hurley-Walker uses novel radio telescopes to explore the universe at some of the longest wavelengths of light. Full bio

Double-click the English transcript below to play the video.

宇宙,无穷无尽
00:13
Space空间, the final最后 frontier边境.
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我六岁的时候就听到了这样的话
00:17
I first heard听说 these words
when I was just six years年份 old,
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这激励了我
00:21
and I was completely全然 inspired启发.
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我想探索新奇的世界
00:23
I wanted to explore探索 strange奇怪 new worlds世界.
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00:26
I wanted to seek寻求 out new life.
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新的生命
00:27
I wanted to see everything
that the universe宇宙 had to offer提供.
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我想了解宇宙中的每一件事物
00:31
And those dreams, those words,
they took me on a journey旅程,
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带着这些梦想,这些信念
我就踏上了追梦旅程
00:35
a journey旅程 of discovery发现,
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一个读书
00:37
through通过 school学校, through通过 university大学,
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上大学,读博士
最后成为一个专业的天文学家的旅程
00:39
to do a PhD博士 and finally最后
to become成为 a professional专业的 astronomer天文学家.
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00:43
Now, I learned学到了 two amazing惊人 things,
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目前为止,我了解了两件有趣的事情
第一件有点令我小伤心
00:46
one slightly unfortunate不幸的,
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当我读博士的时候
00:48
when I was doing my PhD博士.
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我才知道,实际上
00:50
I learned学到了 that the reality现实 was
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我以后根本不能驾驶宇宙飞船
00:53
I wouldn't不会 be piloting试点
a starship星河 anytime任何时候 soon不久.
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但是我同时也了解到宇宙是
奇妙、壮观、广阔的
00:57
But I also learned学到了 that the universe宇宙
is strange奇怪, wonderful精彩 and vast广大,
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实际上宇宙太大,大到用宇宙飞船
根本不可能探索得完
01:02
actually其实 too vast广大
to be explored探讨 by spaceship飞船.
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01:05
And so I turned转身 my attention注意
to astronomy天文学, to using运用 telescopes望远镜.
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所以我把注意力转移到了天文学
用望远镜来探索宇宙
在你们展开想象之前
我先给大家展示一下星空吧
01:09
Now, I show显示 you before you
an image图片 of the night sky天空.
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在世界的任何地方
都能看到这样的景象
01:12
You might威力 see it anywhere随地 in the world世界.
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01:15
And all of these stars明星 are part部分
of our local本地 galaxy星系, the Milky乳白色 Way.
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这些星体是我们星系的一部分,银河系
现在如果你看一看夜空中黑暗的部分
01:19
Now, if you were to go
to a darker part部分 of the sky天空,
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选一个好地方观察,沙漠就行
01:22
a nice不错 dark黑暗 site现场, perhaps也许 in the desert沙漠,
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你也许会看到银河的中心
01:24
you might威力 see the center中央
of our Milky乳白色 Way galaxy星系
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上千亿的星体在你面前散布着
01:27
spread传播 out before you,
hundreds数以百计 of billions数十亿 of stars明星.
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景象极其壮观
01:30
And it's a very beautiful美丽 image图片.
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五彩斑斓
01:32
It's colorful华美.
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当然,这只是我们宇宙的
一个局部的中心
01:33
And again, this is just
a local本地 corner of our universe宇宙.
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许多奇怪的黑色尘埃分散其中
01:37
You can see there's
a sort分类 of strange奇怪 dark黑暗 dust灰尘 across横过 it.
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01:40
Now, that is local本地 dust灰尘
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这些是局部尘埃
他们阻挡了其他星体发出来的光线
01:42
that's obscuring遮蔽 the light of the stars明星.
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但是我们做的还不错
01:45
But we can do a pretty漂亮 good job工作.
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仅仅用肉眼,我们就能
探索宇宙的一个小角落
01:47
Just with our own拥有 eyes眼睛, we can explore探索
our little corner of the universe宇宙.
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所以我们有进步的余地
01:50
It's possible可能 to do better.
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你可以用神奇的哈勃空间望远镜
(来探索宇宙)
01:51
You can use wonderful精彩 telescopes望远镜
like the Hubble哈勃 Space空间 Telescope望远镜.
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01:56
Now, astronomers天文学家
have put together一起 this image图片.
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现在天文学家已经把
收集到的景象放在一起
叫做哈勃深空视场
01:58
It's called the Hubble哈勃 Deep Field领域,
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他们花数百个小时观察这一小块天空
02:00
and they've他们已经 spent花费 hundreds数以百计 of hours小时
observing观察 just a tiny patch补丁 of the sky天空
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相当于比你整条胳膊上的一小块
指甲还小的地方
02:04
no larger than your thumbnail缩略图
held保持 at arm's武器 length长度.
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02:07
And in this image图片
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在这个景象中
你可以看到上千个星系
02:08
you can see thousands数千 of galaxies星系,
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我们知道在整个宇宙中一定还存在
02:10
and we know that there must必须 be
hundreds数以百计 of millions百万, billions数十亿 of galaxies星系
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上亿的星系
02:13
in the entire整个 universe宇宙,
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一些星系跟我们的星系相似
另一些和我们的完全不同
02:15
some like our own拥有 and some very different不同.
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所以你就想着,没问题啊
我可以继续研究
02:18
So you think, OK, well,
I can continue继续 this journey旅程.
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很简单,我只要有一个
足够牛的望远镜就行
02:20
This is easy简单. I can just
use a very powerful强大 telescope望远镜
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然后再拿它看看天空,没问题的
02:23
and just look at the sky天空, no problem问题.
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实际上,如果我们真的这么做的话
就什么都探索不到了
02:25
It's actually其实 really missing失踪 out
if we just do that.
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因为我们到目前为止所说的一切
02:30
Now, that's because
everything I've talked about so far
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仅仅是用可见光看到的,
你们的眼睛就可以看到,
02:32
is just using运用 the visible可见 spectrum光谱,
just the thing that your eyes眼睛 can see,
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这只是宇宙中
02:36
and that's a tiny slice,
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很小的一部分,非常非常小
02:38
a tiny, tiny slice
of what the universe宇宙 has to offer提供 us.
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而且现在就可见光来说,我们也有两个
非常重要的问题需要解决
02:42
Now, there's also two very important重要
problems问题 with using运用 visible可见 light.
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现在不仅不能研究那些
02:46
Not only are we missing失踪 out
on all the other processes流程
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发出其他不可见光的东西
02:49
that are emitting发光 other kinds of light,
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(在可见光范围内)
我们也有两个问题
02:52
but there's two issues问题.
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02:54
Now, the first is that dust灰尘
that I mentioned提到 earlier.
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第一个是我之前提到的尘埃
这些尘埃阻挡了可见光
我们看不到后边的东西
02:57
The dust灰尘 stops停止 the visible可见 light
from getting得到 to us.
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所以我们进一步探索宇宙的话
光线就比之前更少
03:00
So as we look deeper更深
into the universe宇宙, we see less light.
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尘埃阻挡了光线
03:05
The dust灰尘 stops停止 it getting得到 to us.
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03:07
But there's a really strange奇怪 problem问题
with using运用 visible可见 light
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在研究宇宙的过程中,我们在如何应用
可见光方面也有问题
03:10
in order订购 to try and explore探索 the universe宇宙.
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我们先不说这个
03:13
Now take a break打破 for a minute分钟.
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假设你现在站在
喧闹大街的角落,很热闹
03:15
Say you're standing常设 on a corner,
a busy street corner.
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大街上的车川流不息
03:19
There's cars汽车 going by.
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这时候一辆救护车正驶来
03:20
An ambulance救护车 approaches方法.
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03:22
It has a high-pitched高亢 siren警笛.
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警报器发出尖锐的声音
(模仿警报声呼啸而过)
03:24
(Imitates模仿 a siren警笛 passing通过 by)
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在警报器靠近你之后
又远离你的过程中
03:28
The siren警笛 appeared出现 to change更改 in pitch沥青
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它的声调似乎在改变
03:30
as it moved移动 towards and away from you.
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救护车司机不是为了
引起你的注意而改变声调的
03:32
The ambulance救护车 driver司机 did not change更改
the siren警笛 just to mess食堂 with you.
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而是你自身的感觉造成的
03:38
That was a product产品 of your perception知觉.
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随着救护车的靠近
03:40
The sound声音 waves波浪,
as the ambulance救护车 approached接近,
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波长变短
03:43
were compressed压缩,
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所以声调变高
03:44
and they changed higher更高 in pitch沥青.
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之后救护车远离我们,波长变长
03:46
As the ambulance救护车 receded退去,
the sound声音 waves波浪 were stretched拉伸,
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所以听起来声调比较低
03:49
and they sounded满面 lower降低 in pitch沥青.
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光线同样是如此
03:51
The same相同 thing happens发生 with light.
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03:54
Objects对象 moving移动 towards us,
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当物体靠近我们的时候
光波波长变得短,它们看起来更蓝
03:56
their light waves波浪 are compressed压缩
and they appear出现 bluer更蓝.
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当物体远离我们的时候
03:59
Objects对象 moving移动 away from us,
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波长变长,它们看起来更红
04:01
their light waves波浪 are stretched拉伸,
and they appear出现 redder更红.
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我们称此为光波的蓝移效应和红移效应
04:04
So we call these effects效果
blueshift蓝移 and redshift红移.
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04:08
Now, our universe宇宙 is expanding扩大,
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我们的宇宙在不断扩张
所以事物之间在彼此远离
04:11
so everything is moving移动 away
from everything else其他,
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这就意味着,在我们看来,所有的事物
都在向红移的方向发展
04:15
and that means手段
everything appears出现 to be red.
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04:19
And oddly奇怪 enough足够, as you look
more deeply into the universe宇宙,
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有趣的是,你越向宇宙深处看
远处的物体移动的就越快越远
04:22
more distant遥远 objects对象
are moving移动 away further进一步 and faster更快,
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他们看起来就越红
04:27
so they appear出现 more red.
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所以我们回到哈勃深空视场
04:29
So if I come back to the Hubble哈勃 Deep Field领域
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通过哈勃望远镜
04:32
and we were to continue继续
to peer窥视 deeply into the universe宇宙
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看向宇宙深处
04:35
just using运用 the Hubble哈勃,
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我们看得越远
04:36
as we get to a certain某些 distance距离 away,
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事物在我们的视线中就越红
04:39
everything becomes red,
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04:41
and that presents礼物 something of a problem问题.
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这就出现问题了
实际上在更远处
04:43
Eventually终于, we get so far away
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所有的东西都转换成了红外线
04:46
everything is shifted into the infrared红外线
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我们根本什么都看不看到
04:49
and we can't see anything at all.
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所以这个问题必须要解决
04:51
So there must必须 be a way around this.
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否则我就被困住了
04:53
Otherwise除此以外, I'm limited有限 in my journey旅程.
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在红移效应困扰我之前
04:55
I wanted to explore探索 the whole整个 universe宇宙,
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我想探索的是全宇宙
并不只是我用肉眼看到的
04:57
not just whatever随你 I can see,
you know, before the redshift红移 kicks in.
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05:02
There is a technique技术.
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我们有一项技术
叫做射电天文学
05:03
It's called radio无线电 astronomy天文学.
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天文学家已经应用了十几年
05:04
Astronomers天文学家 have been
using运用 this for decades几十年.
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这是个非常有趣的技术
05:07
It's a fantastic奇妙 technique技术.
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这个是帕克斯射电望远镜
我们亲切的叫它“盘子”
05:08
I show显示 you the Parkes帕克斯 Radio无线电 Telescope望远镜,
affectionately深情 known已知 as "The Dish."
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你们也许看过这个电影
05:12
You may可能 have seen看到 the movie电影.
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无线电简直棒极了
05:13
And radio无线电 is really brilliant辉煌.
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它让我们进一步探索宇宙
05:15
It allows允许 us to peer窥视 much more deeply.
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我们不用被那些尘埃遮挡视线了
05:18
It doesn't get stopped停止 by dust灰尘,
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所以你可以看到宇宙中的任何事物
05:20
so you can see everything in the universe宇宙,
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红移效应的问题也不那么棘手了
05:23
and redshift红移 is less of a problem问题
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05:24
because we can build建立 receivers接收器
that receive接收 across横过 a large band.
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因为我们有接收器
能够接受穿过岩石的射线
所以我们用帕克斯
看向宇宙中心的时候
05:28
So what does Parkes帕克斯 see when we turn it
to the center中央 of the Milky乳白色 Way?
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能看到一些有趣的东西对吧
05:32
We should see something fantastic奇妙, right?
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我们的确看到了一些有趣的东西
05:35
Well, we do see something interesting有趣.
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那些尘埃看不到了
05:38
All that dust灰尘 has gone走了.
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就像我之前说的,
无线电穿过了尘埃,所以问题解决了
05:39
As I mentioned提到, radio无线电 goes
straight直行 through通过 dust灰尘, so not a problem问题.
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05:43
But the view视图 is very different不同.
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但是景象却变得不一样了
我们能看到银河的中心在闪烁
05:45
We can see that the center中央
of the Milky乳白色 Way is aglow发红的,
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这些并不是星光
05:49
and this isn't starlight星光.
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这种光叫做同步加速器辐射
05:51
This is a light called
synchrotron同步加速器 radiation辐射,
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05:55
and it's formed形成 from electrons电子
spiraling螺旋式上升 around cosmic宇宙的 magnetic磁性 fields领域.
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来自宇宙磁场周围旋转的电子
所以这一平面里的光线就会闪烁
06:00
So the plane平面 is aglow发红的 with this light.
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我们也能够看到奇怪的成团的东西
06:03
And we can also see
strange奇怪 tufts coming未来 off of it,
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06:06
and objects对象 which哪一个 don't appear出现 to line线 up
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以及在我们肉眼看起来
分散、没有序列的东西
06:09
with anything that we can see
with our own拥有 eyes眼睛.
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06:12
But it's hard to really
interpret this image图片,
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我很难分析这个图像
06:14
because as you can see,
it's very low resolution解析度.
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因为很明显,它的分辨率非常低
射电具有很长的波长
06:17
Radio无线电 waves波浪 have a wavelength波长 that's long,
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06:19
and that makes品牌 their resolution解析度 poorer.
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使其分辨率更低
而且这个图像还是黑白的
06:22
This image图片 is also black黑色 and white白色,
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06:24
so we don't really know
what is the color颜色 of everything in here.
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所以我们不知道那些景象
到底是什么颜色的
06:28
Well, fast-forward快进 to today今天.
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快进到当下,
我们建造的望远镜
06:30
We can build建立 telescopes望远镜
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能克服这些问题了
06:31
which哪一个 can get over these problems问题.
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这是来默奇森射电天文观测台的照片
06:34
Now, I'm showing展示 you here an image图片
of the Murchison默奇森 Radio无线电 Observatory天文台,
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这是一个建造射电望远镜的好地方
06:37
a fantastic奇妙 place地点
to build建立 radio无线电 telescopes望远镜.
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很平坦,很干燥
06:40
It's flat平面, it's dry,
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06:42
and most importantly重要的, it's radio无线电 quiet安静:
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最重要的是,不受其他无线电的干扰
没有移动电话,没有无线网,什么都没有
06:45
no mobile移动 phones手机, no Wi-Fi无线上网, nothing,
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06:48
just very, very radio无线电 quiet安静,
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十分十分清净
06:51
so a perfect完善 place地点
to build建立 a radio无线电 telescope望远镜.
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作为搭建射电望远镜的地方堪称完美
06:54
Now, the telescope望远镜 that I've been
working加工 on for a few少数 years年份
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现在这个我已经使用好几年的望远镜
叫做默奇森广角阵列
06:57
is called the Murchison默奇森 Widefield广角 Array排列,
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这是它一点点建造的过程
06:59
and I'm going to show显示 you
a little time lapse失误 of it being存在 built内置.
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这是一群在珀斯的大学本科生和
07:02
This is a group of undergraduate大学本科
and postgraduate研究生 students学生们
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07:06
located位于 in Perth珀斯.
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研究生
我们叫他们学生军
07:07
We call them the Student学生 Army军队,
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他们牺牲自己的时间来
建造这个射电望远镜
07:09
and they volunteered自告奋勇 their time
to build建立 a radio无线电 telescope望远镜.
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没有课程学分
07:11
There's no course课程 credit信用 for this.
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07:14
And they're putting together一起
these radio无线电 dipoles偶极子.
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这些学生把偶极子组装起来
它们能像调频收音机或者
电视一样接收低频信号
07:17
They just receive接收 at low frequencies频率,
a bit like your FM调频 radio无线电 or your TV电视.
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我们把它们建在了沙漠里
07:23
And here we are deploying部署 them
across横过 the desert沙漠.
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最后一部分占澳大利亚西部沙漠的
07:26
The final最后 telescope望远镜
covers盖子 10 square广场 kilometers公里
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07:28
of the Western西 Australian澳大利亚 desert沙漠.
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10平方公里
07:30
And the interesting有趣 thing is,
there's no moving移动 parts部分.
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有趣的是,它们不能移动
我们把这些小天线
07:33
We just deploy部署 these little antennas天线
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放在在六角形的网上
07:36
essentially实质上 on chicken mesh网孔.
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成本相当的低
07:37
It's fairly相当 cheap低廉.
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07:39
Cables电缆 take the signals信号
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天线上的电缆
接收信号
07:41
from the antennas天线
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然后把信号传递给中央处理器
07:43
and bring带来 them
to central中央 processing处理 units单位.
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这样的望远镜遍布整个沙漠
07:45
And it's the size尺寸 of this telescope望远镜,
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07:47
the fact事实 that we've我们已经 built内置 it
over the entire整个 desert沙漠
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它的占地面积使它在
处理问题能力的方面
07:50
that gives us a better
resolution解析度 than Parkes帕克斯.
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比帕克斯的望远镜更好
所有的电缆最后汇成一股
07:53
Now, eventually终于 all those cables电缆
bring带来 them to a unit单元
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07:57
which哪一个 sends发送 it off
to a supercomputer超级计算机 here in Perth珀斯,
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把信息传递到珀斯的
一个超级计算机上
08:01
and that's where I come in.
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那就是我要工作的部分
(叹气)
08:03
(Sighs叹息)
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研究无线电数据
08:04
Radio无线电 data数据.
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过去五年的时间
08:05
I have spent花费 the last five years年份
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08:07
working加工 with very difficult,
very interesting有趣 data数据
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我一直在研究这些困难却有趣
08:10
that no one had really looked看着 at before.
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之前没有人了解过的数据
08:12
I've spent花费 a long time calibrating校准 it,
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我在这个超级计算机上花了
08:14
running赛跑 millions百万 of CPU中央处理器 hours小时
on supercomputers超级计算机
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数以百万计的CPU时数校对
08:18
and really trying to understand理解 that data数据.
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并试图弄清楚这些数据
08:21
And with this telescope望远镜,
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通过这套望远镜
这些数据
08:23
with this data数据,
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我们对整个南半球的
星空做了一番仔细观察
08:24
we've我们已经 performed执行 a survey调查
of the entire整个 southern南部的 sky天空,
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08:28
the GaLactic and Extragalactic河外星系
All-sky全天空 MWAMWA Survey调查,
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银河系及超银河系默奇森
广角阵列全天候研究
08:33
or GLEAMGLEAM, as I call it.
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或者简称GLEAM
08:36
And I'm very excited兴奋.
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我非常兴奋
08:37
This survey调查 is just about to be published发表,
but it hasn't有没有 been shown显示 yet然而,
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这个研究结果快要公之于世了
但是目前还没有
所以你们还算是第一批了解这些
08:41
so you are literally按照字面 the first people
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08:43
to see this southern南部的 survey调查
of the entire整个 sky天空.
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关于南半球星空研究的人
我也很高兴分享给你们
研究中的部分图像
08:46
So I'm delighted欣喜的 to share分享 with you
some images图片 from this survey调查.
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现在,请想象一下你们就在默奇森
08:50
Now, imagine想像 you went to the Murchison默奇森,
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08:52
you camped扎营 out underneath the stars明星
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在满天星斗下露营
你抬头仰望南部星空
08:54
and you looked看着 towards the south.
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看到了南极
08:56
You saw the south's南方 celestial天上 pole,
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看到银河在上升
08:58
the galaxy星系 rising升起.
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如果我让射电光弱一点
08:59
If I fade褪色 in the radio无线电 light,
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09:02
this is what we observe with our survey调查.
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就会看到我们研究中所观察到的景象
你会看到银河不再黑乎乎的充满尘埃
09:04
You can see that the galactic plane平面
is no longer dark黑暗 with dust灰尘.
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它被星空中数以千计的点点
09:07
It's alight with synchrotron同步加速器 radiation辐射,
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和同步加速器辐射点亮
09:10
and thousands数千 of dots are in the sky天空.
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广袤的,靠近我们星系的麦哲伦云
09:12
Our large Magellanic麦哲伦 Cloud,
our nearest最近的 galactic neighbor邻居,
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09:16
is orange橙子 instead代替
of its more familiar blue-white蓝白色.
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其实是橘色的,而不是接近蓝白色的
这里面有很多的东西值得研究
让我们放大看一下
09:19
So there's a lot going on in this.
Let's take a closer接近 look.
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09:22
If we look back
towards the galactic center中央,
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如果我们想想看我刚刚给你们展示的
帕克森拍摄的银河中心的景象
09:25
where we originally本来 saw the Parkes帕克斯 image图片
that I showed显示 you earlier,
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低分辨率,黑白色的
09:28
low resolution解析度, black黑色 and white白色,
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然后再看GLEAM的图像
09:30
and we fade褪色 to the GLEAMGLEAM view视图,
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你们会发现这个分辨率提升了一百倍
09:34
you can see the resolution解析度
has gone走了 up by a factor因子 of a hundred.
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我们看到的是充满色彩的星空
09:38
We now have a color颜色 view视图 of the sky天空,
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五彩斑斓
09:40
a technicolor彩色印片法 view视图.
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这些颜色并不是有偏差的颜色
09:42
Now, it's not a false color颜色 view视图.
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09:45
These are real真实 radio无线电 colors颜色.
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他们是真正的无线电波发射出来的颜色
我们已经实现把低频率的显示成红色
09:48
What I've doneDONE is I've colored有色
the lowest最低 frequencies频率 red
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09:51
and the highest最高 frequencies频率 blue蓝色,
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把高频率的显示成蓝色
中间频率偏绿色
09:53
and the middle中间 ones那些 green绿色.
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这就给我们呈现了五颜六色的景象
09:54
And that gives us this rainbow彩虹 view视图.
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这些也不仅仅是伪色
09:56
And this isn't just false color颜色.
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这个图片里的颜色是在显示
09:59
The colors颜色 in this image图片
tell us about the physical物理 processes流程
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宇宙中事物的物理过程
10:02
going on in the universe宇宙.
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举个例子,如果你看向银河的一个平面
10:03
So for instance, if you look
along沿 the plane平面 of the galaxy星系,
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同步加速器使它变亮
10:06
it's alight with synchrotron同步加速器,
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呈现出带鲜红的橙色画面
10:08
which哪一个 is mostly大多 reddish orange橙子,
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但是我们仔细再看一下
我们会看到蓝色的点
10:10
but if we look very closely密切,
we see little blue蓝色 dots.
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现在,我们再放大
10:14
Now, if we zoom放大 in,
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这些蓝色的点实际上就是离子化等离子体
10:15
these blue蓝色 dots are ionized电离 plasma等离子体
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它们在明亮的星体周围
10:18
around very bright stars明星,
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并且挡住了红色光线
10:20
and what happens发生
is that they block the red light,
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所以它们看起来是蓝色的
10:23
so they appear出现 blue蓝色.
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我们通过这些可以知道在我们银河中
10:25
And these can tell us
about these star-forming恒星形成 regions地区
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10:28
in our galaxy星系.
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形成星体的地方
并且一下子就能看出来
10:30
And we just see them immediately立即.
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因为当我们望向宇宙
颜色就会告诉我们它们在那儿
10:31
We look at the galaxy星系,
and the color颜色 tells告诉 us that they're there.
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你们还能在这一银河平面中看到
10:34
You can see little soap肥皂 bubbles泡泡,
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小的,肥皂泡一样的圆形图像
10:36
little circular images图片
around the galactic plane平面,
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这些是超新星残余物
10:39
and these are supernova超新星 remnants残余.
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当一个星体爆炸的时候
10:42
When a star explodes爆炸,
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10:44
its outer shell贝壳 is cast off
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它的外表壳就会被炸开
然后这颗星体会飘忽在宇宙中
聚合其他的物质
10:46
and it travels旅行 outward向外 into space空间
gathering搜集 up material材料,
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由此形成新的小的保护壳
10:50
and it produces产生 a little shell贝壳.
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对天文学家来讲
那些超新星残余物的去向
10:52
It's been a long-standing由来已久
mystery神秘 to astronomers天文学家
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一直是一个神秘的过程
10:56
where all the supernova超新星 remnants残余 are.
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我们都知道在宇宙空间中
一定有许多高能电子
10:58
We know that there must必须 be a lot
of high-energy高能量 electrons电子 in the plane平面
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11:03
to produce生产 the synchrotron同步加速器
radiation辐射 that we see,
240
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它们产生我们所看见的
同步加速器辐射
我们认为它们是由超新星残余物产生的
11:06
and we think they're produced生成
by supernova超新星 remnants残余,
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但是它们看起来好像还不是很多
11:08
but there don't seem似乎 to be enough足够.
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幸运的是,GLEAM能够非常非常准确的
探测到超新星残余物
11:10
Fortunately幸好, GLEAMGLEAM is really, really
good at detecting检测 supernova超新星 remnants残余,
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11:14
so we're hoping希望 to have
a new paper out on that soon不久.
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所以我们有望于
这一方面研究成果的产生
11:17
Now, that's fine.
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好,我们再继续说
11:19
We've我们已经 explored探讨 our little local本地 universe宇宙,
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我们已经探索了我们的局部宇宙
11:21
but I wanted to go deeper更深,
I wanted to go further进一步.
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但是我想更进一步的探索,深入研究
我想探索银河以外的宇宙
11:23
I wanted to go beyond the Milky乳白色 Way.
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现在在图片的右上方我们能够看到
一个很有意思的东西
11:26
Well, as it happens发生, we can see a very
interesting有趣 object目的 in the top最佳 right,
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这是局部电波星系
11:30
and this is a local本地 radio无线电 galaxy星系,
250
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2216
11:32
Centaurus半人马座 A.
251
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半人马座A
11:34
If we zoom放大 in on this,
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如果我们放大来看
我们能够看到两片巨大的羽毛一样的东西
11:35
we can see that there are
two huge巨大 plumes羽毛 going out into space空间.
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然后你们再看两片羽毛的中间
11:39
And if you look right in the center中央
between之间 those two plumes羽毛,
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你会看到和一个我们银河很像的星系
11:42
you'll你会 see a galaxy星系 just like our own拥有.
255
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11:44
It's a spiral螺旋. It has a dust灰尘 lane车道.
256
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它是螺旋状的,有一条尘埃带
就是一个普通的星系
11:47
It's a normal正常 galaxy星系.
257
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但是这些星点只能在无线电中才能看到
11:49
But these jets喷气机
are only visible可见 in the radio无线电.
258
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11:52
If we looked看着 in the visible可见,
we wouldn't不会 even know they were there,
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如果我们用肉眼看的话
根本不知道它们在那里
他们比主星系还要大上千倍
11:55
and they're thousands数千 of times larger
than the host主办 galaxy星系.
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那么发生了什么
这些星点是从哪里来的呢
11:59
What's going on?
What's producing生产 these jets喷气机?
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我们都知道每个星系中心
12:03
At the center中央 of every一切 galaxy星系
that we know about
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都有一个超级大的黑洞
12:06
is a supermassive超大 black黑色 hole.
263
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12:09
Now, black黑色 holes are invisible无形.
That's why they're called that.
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黑洞是不可见的
这就是为什么叫做黑洞
你们能看见的只有
它们周围改变轨迹的光线
12:12
All you can see is the deflection偏转
of the light around them,
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当一颗星体或者一团星云进入其轨道
12:15
and occasionally偶尔, when a star
or a cloud of gas加油站 comes into their orbit轨道,
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12:19
it is ripped撕开 apart距离 by tidal潮汐 forces军队,
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就会被潮汐力分裂
形成我们所说的吸积盘
12:22
forming成型 what we call an accretion吸积 disk磁盘.
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吸积盘在X光下很明亮
12:25
The accretion吸积 disk磁盘
glows光晕 brightly明亮地 in the x-raysx射线,
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并且巨大的磁场可以让物质
12:28
and huge巨大 magnetic磁性 fields领域
can launch发射 the material材料 into space空间
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以光速进入宇宙空间
12:33
at nearly几乎 the speed速度 of light.
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所以这些星点对无线电可见
12:35
So these jets喷气机 are visible可见 in the radio无线电
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这就是我们的研究成果
12:39
and this is what we pick up in our survey调查.
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所以我们现在看到的是
一个电波星系,很不错
12:42
Well, very well, so we've我们已经 seen看到
one radio无线电 galaxy星系. That's nice不错.
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12:46
But if you just look
at the top最佳 of that image图片,
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但是我们再看最上方
也有一个电波星系
12:48
you'll你会 see another另一个 radio无线电 galaxy星系.
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这个就小一点了,因为离我们较远
12:50
It's a little bit smaller,
and that's just because it's further进一步 away.
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好了,两个星系了
12:53
OK. Two radio无线电 galaxies星系.
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我们能够看到这样,很不错了
12:56
We can see this. This is fine.
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12:58
Well, what about all the other dots?
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那么剩下那些点怎么办呢
你们可能会觉得那些就是星体
12:59
Presumably想必 those are just stars明星.
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但你们错了
13:01
They're not.
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那些都是电波星系
13:03
They're all radio无线电 galaxies星系.
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13:05
Every一切 single one of the dots in this image图片
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每一个在这上面成点状的
都是一个遥远的星系
13:08
is a distant遥远 galaxy星系,
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13:10
millions百万 to billions数十亿 of light-years光年 away
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离我们数十亿光年远
这些星系的中心也是把物质以光速
13:12
with a supermassive超大
black黑色 hole at its center中央
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甩进宇宙空间的黑洞
13:15
pushing推动 material材料 into space空间
at nearly几乎 the speed速度 of light.
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很令人兴奋
13:19
It is mind-blowing令人兴奋.
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13:21
And this survey调查 is even larger
than what I've shown显示 here.
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我展示的只是研究成果的冰山一角
如果我把整个研究成果都展示出来
13:25
If we zoom放大 out to
the full充分 extent程度 of the survey调查,
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13:28
you can see I found发现 300,000
of these radio无线电 galaxies星系.
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你会看到30万个这样的无线电星系
的确是个费劲的活儿
13:32
So it's truly an epic史诗 journey旅程.
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13:35
We've我们已经 discovered发现 all of these galaxies星系
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我们对所有这些星系的
13:37
right back to the very first
supermassive超大 black黑色 holes.
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研究都追溯到了最早的超质量黑洞
13:41
I'm very proud骄傲 of this,
and it will be published发表 next下一个 week.
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我很为之自豪
下周研究成果就会公开
这还不是全部
13:45
Now, that's not all.
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我已经探究了迄今为止宇宙的最深处
13:48
I've explored探讨 the furthest最远 reaches到达
of the galaxy星系 with this survey调查,
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但在这幅图像之外还有很多信息
13:52
but there's something
even more in this image图片.
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现在我们回顾一下时间伊始
13:56
Now, I'll take you right back
to the dawn黎明 of time.
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宇宙形成之时经历了大爆炸
13:59
When the universe宇宙 formed形成,
it was a big bang,
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留下一片氢的汪洋
14:03
which哪一个 left the universe宇宙
as a sea of hydrogen,
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14:07
neutral中性 hydrogen.
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中性氢
当第一个星系形成的时候
14:08
And when the very first stars明星
and galaxies星系 switched交换的 on,
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它们把氢气电离了
14:11
they ionized电离 that hydrogen.
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所以宇宙从中性不带电
变成了电离的了
14:13
So the universe宇宙 went
from neutral中性 to ionized电离.
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我们周围就产生了电信号
14:18
That imprinted a signal信号 all around us.
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无形中像力一样渗透到了
14:21
Everywhere到处, it pervades弥漫 us,
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14:23
like the Force.
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我们周围
因为这是很长很长以前发生的事情了
14:24
Now, because that happened发生 so long ago,
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14:29
the signal信号 was redshifted红移,
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1800
现在那些信号已经红移了
所以是低频的
14:31
so now that signal信号
is at very low frequencies频率.
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和我研究的是一样的频率
14:34
It's at the same相同 frequency频率 as my survey调查,
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14:37
but it's so faint.
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但是这频率太微弱了
14:38
It's a billionth十亿 the size尺寸
of any of the objects对象 in my survey调查.
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是我们研究的物体频率的十亿分之一
14:43
So our telescope望远镜 may可能 not be quite相当
sensitive敏感 enough足够 to pick up this signal信号.
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所以我们的望远镜并不能很灵敏的
探索到这些信号
然而,又有了新的射电望远镜
14:48
However然而, there's a new radio无线电 telescope望远镜.
317
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14:50
So I can't have a starship星河,
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所以虽然我不能乘坐宇宙飞船
但是我很高兴拥有
14:52
but I can hopefully希望 have
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世界上最大的射电望远镜
14:53
one of the biggest最大
radio无线电 telescopes望远镜 in the world世界.
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我们正在建平方公里阵列射电望远镜
一个新的射电望远镜
14:56
We're building建造 the Square广场 Kilometre公里 Array排列,
a new radio无线电 telescope望远镜,
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15:00
and it's going to be a thousand
times bigger than the MWAMWA,
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比默契森广角阵列还大上千倍
灵敏上千倍,效果也更好
15:03
a thousand times more sensitive敏感,
and have an even better resolution解析度.
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所以我们会发现数千万的星系
15:06
So we should find
tens of millions百万 of galaxies星系.
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或许,再深入研究那些信号
15:08
And perhaps也许, deep in that signal信号,
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我们会发现宇宙中形成的
第一颗星体和星系
15:10
I will get to look upon the very first
stars明星 and galaxies星系 switching交换 on,
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以及时间诞生的那一刻
15:15
the beginning开始 of time itself本身.
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15:17
Thank you.
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谢谢
(掌声)
15:19
(Applause掌声)
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Translated by Luo Xinzhu
Reviewed by Psycho Decoder

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ABOUT THE SPEAKER
Natasha Hurley-Walker - Astronomer
Natasha Hurley-Walker uses novel radio telescopes to explore the universe at some of the longest wavelengths of light.

Why you should listen

Dr. Natasha Hurley-Walker recently completed an astronomical survey of the entire southern sky, revealing the radio glow of our own Milky Way galaxy as well as hundreds of thousands of distant galaxies: the GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey. Unlike previous work, GLEAM is the first "radio color" survey, observed across such a wide range of frequencies that the unique spectrum of every object can be used to understand its underlying physics.

An Early-Career Research Fellow based at the Curtin University node of the International Centre for Radio Astronomy Research, in Perth, Western Australia, Hurley-Walker is part of the international Murchison Widefield Array (MWA) collaboration, spanning thirteen institutes across six countries. At her fingertips are tens of petabytes of data collected by the MWA since 2013, which she processes using powerful supercomputers at the nearby Pawsey Centre. Hurley-Walker earned a PhD in Radio Astronomy at the University of Cambridge by commissioning and using a new radio telescope to perform its first science observations. The experience directly transferred to the MWA, which she also helped to commission.

The MWA is a precursor to the Square Kilometer Array (SKA), what will be the largest radio telescope in the world, set to come online in the 2020s. By developing software and techniques to deal with data from the MWA, creating pathfinding maps of the sky and training a new generation of astronomers in cutting-edge techniques, Hurley-Walker is working to lay the scientific groundwork for the commissioning of the SKA. In 2016 Hurley-Walker was awarded an Australian SKA Fellowship in order to visit the SKA headquarters and transfer lessons from her commissioning experiences as well as develop her survey into a useful calibration model for the SKA.

Hurley-Walker is passionate about scientific outreach and keynoted talks in 2013 and 2017 at Astrofest, Australia's largest public astronomy festival. So that anyone in the world can see the sky with the same radio eyes as her, she created the GLEAMoscope , an interactive online viewer that shows the universe at radio wavelengths compared to other frequencies, including the more familiar "optical" spectrum. It being the 21st century, there's also an app: check out GLEAM on the Google Play store. In 2017 Natasha won the "Best Timelapse" category in the Astofest astrophotography competition with her colleague John Goldsmith for their creation of a composite video showing both the optical and radio sky. For more detail on Hurley-Walker's work, check out her article on TheConversation.

Working with cutting-edge data is tough, but sometimes hides serendipitous gems which Hurley-Walker has unearthed, like the faintest dying radio galaxy ever discoveredwhistling plasma ducts in the Earth's ionosphere and some of the youngest and weirdest radio galaxies ever found. View a complete list of Hurley-Walker's publications.

More profile about the speaker
Natasha Hurley-Walker | Speaker | TED.com