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阿雷西博望远镜能拯救世界 – 译学馆
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阿雷西博望远镜能拯救世界

How The Arecibo Telescope Could Help Save The World

我现在位于波多黎各的阿雷西博天文台
I’m at the Arecibo Observatory in Puerto Rico.
这是世界上最大的射电望远镜之一 是一个300米宽的碟状物
It is one of the world’s largest radio telescopes, with a dish 300 metres across.
来之前我已经看过相关图片和视频了
And I had seen pictures and video of this before I came here,
但老实说 摄像机并不能将如此庞大的规模全拍下来
but, honestly, the sheer scale is impossible to get across on camera.
它实在是太大了
It is massive.
50年来 它一直在倾听着苍穹 或许有一天
For 50 years, it’s been listening to the sky, and one day,
它就能拯救这个世界
it might just save the world.
阿雷西博已经成为发现宇宙宏大结构计划中的一部分
Arecibo’s been part of discovering the large-scale structure of the universe.
我们发现了遥远星系中的生命起源之前的分子
We’ve discovered pre-biotic molecules in distant galaxies,
第一颗毫秒脉冲星 第一颗系外行星
the first millisecond pulsar, the first exoplanets.
众所周知 最著名的当属荣获诺贝尔奖的
The big one, which everyone knows about,
脉冲双星的发现
is the Nobel Prize for the discovery of the binary pulsar
其轨道的衰变方式与广义相对论所预言的完全一样
and the way that its orbit decayed exactly as predicted by general relativity.
这里有50年来的很多发现
There’s 50 years of discoveries here,
有关阿雷西博的发现我能讲个50年
I could talk for 50 years on discoveries of Arecibo.
天文台最让人难以置信的事情之一就是
One of the most incredible things about the observatory is this,
我现在所在的悬空平台
the suspended platform that I’m standing on right now.
整个巨大的结构是悬挂在空中电缆上的
This entire colossal structure is suspended in the air on cables,
就像吊桥一样 下面没有柱子
like a suspension bridge, there are no pillars underneath
起到支撑作用 也不会妨碍道路
holding this up and getting in the way.
所有重量都由碟状物周围的三座混凝土塔支撑着
All this weight is being carried by the three concrete towers around the dish.
这个平台不是静态的 而是移动的
And this platform isn’t static: big parts of it move.
通过南北短距离移动一下望远镜
The telescope, by going a short way north and south,
其实能够看到大约三分之一的天空
can actually see about a third of the total sky from here.
整个碟状物主要的碗状部分是球形的
The main bowl of this dish is spherical.
但是 难题是
The complication, though, is:
球面镜没有焦点 就和双曲镜面一样
a spherical mirror doesn’t have a point of focus, like a hyperbolic mirror,
但我们已经习惯了有焦点的大型光学望远镜和大多数的大型射电望远镜
which we’re used to with big optical telescopes and most big radio telescopes.
所以 为了让信号集中到一个焦点上
And so, in order to get the signal to a focus,
罗马穹顶拥有两个小型反射器
the Gregorian dome contains two smaller reflectors.
这些小型反射器实际上能够将一切都引向一个焦点
These smaller reflectors actually bring everything to a point focus.
这就意味着 在罗马穹顶里面 我们可以有更宽波段的接收器
That means, in the Gregorian dome, we can have much wider band receivers
频率可以从0.3GHz覆盖至10GHz
and cover from 0.3GHz to 10GHz in frequency.
阿雷西博望远镜可以做一些大部分射电望远镜都做不到的事情 那就是传播信号
Arecibo can do something that most radio telescopes can’t: it can transmit.
最著名的就是在1974年 它将阿雷西博的信息传达到了其它星球
Famously, in 1974, it beamed the Arecibo message out to the stars,
但是还有更加实用的方法
but there are also some more practical uses
将大能量脉冲传到太空 那就是雷达
for sending big pulses of energy into space: radar.
阿雷西博能将雷达信号发射至太阳系里的行星 小行星以及
Arecibo can bounce radar signals off planets, asteroids and, well,
附近的任何事物上 并接受传回的信号
anything nearby in the solar system.
并且能够构建处于黑暗之中的清晰图像
And it can build up clear pictures of what’s out there in the dark.
使用雷达图像的优点是
The advantage of using the radar imaging is
你能够看到相较于光学图像更好更优秀的成像形状
you can actually see the shape much better compared to optical imaging.
如果距离够近 我们甚至能看到表面的石头
We can actually see boulders on the surface if they are close enough,
看起来可能像一块骨头或者像一个……甘薯
if it looks like a bone or if it looks like a… sweet potato!
S频段发射机是一种大功率的发射机
The S-band transmitter is a high-powered transmitter
它的工作频率是2380MHz 属于S频段
that works at 2380MHz of frequency, that’s the S-band.
整个发射机功率以百万瓦来计
The whole transmitter’s a megawatt of power.
这个发射机会产生一个能量束
This transmitter produces a beam of power,
如果你把你的手放上面 你就会被烧伤
and if you put your hand right through it you could get burned.
我们主要观测近地小行星
We mostly observe near-Earth asteroids.
当我们发现了新的小行星而它的轨道还没有确定时
When new asteroids are found their orbit is not very well defined yet,
我们主要的工作就是获取更多的轨道信息
the main thing that we can do is really enhance the orbit information.
发射一个信号 然后碰到了一个移动的物体
You transmit a signal and when it hits a moving object
信号波长的改变取决于
the wavelength of the signal changes depending on
这个小行星正在靠近观测者还是正在远离观测者
if the asteroid is moving towards the observer or away from the observer.
用这种方法我们可以得到小行星速度的一个估计数
In that way we can actually get an estimate, to millimetres per second,
精度为毫米/秒
of the velocity of the asteroid.
每当发现了新的小行星 就可以确定之间的距离
When new asteroids are found the distance can be determined
可以精确到几百米 甚至几十米
to hundreds of metres, even tens of metres.
我们可以得到很精确的信息 这个小行星十年后会到达哪个地方
We can get very accurate information of where the asteroid will be
甚至是一百年以后的位置
from now to a decade forward, or even a century forward.
根据小行星Apophis的初步轨道信息显示
Asteroid Apophis, the preliminary orbiting information showed
它有可能会与地球发生碰撞
that it actually might hit the Earth.
在使用雷达观测过后 可以确定它将会到达距离我们非常近的位置
After it was observed with radar they could determine it will come super-close,
它很可能会干扰到一些绕地球轨道运行的卫星
it will probably disturb some of the satellites that are orbiting Earth,
但是它不会撞击到地球
but it doesn’t hit the Earth.
知道这一点很重要 因为现在
That’s very important to know, because now
我们知道没有必要派遣布鲁斯威利斯去偏转小行星了
we know we don’t have to send Bruce Willis to deflect the asteroid(!)
在所有自然灾害中
Of all natural catastrophes,
撞击是我们可以避免的一件事
impacts are the one thing that we can actually avoid.
地震 火山喷发 对于它们的发生我们其实帮不上什么忙
Earthquakes, volcanoes, they just happen and we can’t actually help that.
但是对于一个小行星如果我们观测的足够早
But if we can observe an asteroid early enough
我们就有机会使它偏离轨道
we have an opportunity to deflect it.
非常感谢阿雷西博天文台的所有工作人员
Thank you so much to everyone at the Arecibo Observatory.
如果你有兴趣更深入地了解他们以及他们的发现
If you’d like to know more about them and their discoveries
下拉介绍获取更多链接
pull down the description for lots of links,
如果你想看视频的幕后情景
and if you want to see behind the scenes on this video
画面中的美男子Matt已经拍摄了大量的镜头
then Matt, who’s on camera, has been taking a load of footage
并将其放到了第二频道上面
and has put it together for the second channel.

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视频概述

阿雷西博望远镜能够让地球避免被小行星撞击,让人类世界免于消亡

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收集自网络

翻译译者

jameschan

审核员

Ah~Qiu

视频来源

https://www.youtube.com/watch?v=d3WiRunOsWY

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