哈勃130亿年前的照片：英语精读讲义

On the 24th of April 1990,

1990年4月24日，

space shuttle Discovery launched the Hubble telescope into orbit.

发现号航天飞机将哈勃望远镜送入轨道。

This was an exciting time for space exploration,

那是太空探索激动人心的时刻，

as Hubble promised to produce mind-boggling images, 習語

因为哈勃有望拍摄出令人惊叹的图像，

showing us an early view of our universe as it was forming.

向我们展示宇宙形成初期的景象。

But as soon as Hubble came online, 講解

但哈勃一上线，

scientists noticed a serious problem with its mirror.

科学家们就发现它的主镜存在严重问题。

Although this was the most precisely cut mirror ever made,

尽管这是有史以来切割得最精确的镜面，

a slight defect of just 2,000 nanometers meant that Hubble failed to produce sharp images.

但仅仅2000纳米的微小缺陷意味着哈勃无法生成清晰的图像。

After 3 years,

三年后，

scientists managed to produce a fix for the mirror, 語法

科学家们成功为镜面制定了修复方案，

and Hubble began scanning the universe for its secrets.

哈勃便开始扫描宇宙寻找它的秘密。

Since then, 語法

从那时起，

Hubble has operated for nearly 30 years,

哈勃已经运行了近30年，

capturing the most stunning images of distant stars and galaxies.

捕捉到了遥远恒星和星系最令人惊叹的图像。

But, like everything,

但是，就像世间万物一样，

Hubble has its limits,

哈勃也有其极限，

and the world's most famous telescope will eventually come to an end in the not-too-distant future. 短語搭配

这台世界上最著名的望远镜最终将在不久的将来走向终结。

But how long does it have left? 語法

它还剩下多少时间？

And why has it reached a limit in terms of what it can observe? 短語搭配

为什么它在观测能力上达到了极限？

Throughout its lifetime,

在其整个生命周期中，

Hubble has taken millions of amazing pictures.

哈勃拍摄了数以百万计的惊人照片。

It's able to observe other parts of the electromagnetic spectrum that an ordinary telescope couldn't see. 用詞

它能够观测到普通望远镜无法看到的电磁波谱的其他部分。

Since it's outside of Earth's atmosphere,

因为它在地球大气层之外，

it has an unobstructed view of the universe,

它拥有毫无遮挡的宇宙视野，

which allows it to capture objects

这使得它能够捕捉到

that are dimmer and much more distant than a ground-based telescope ever could.

比地面望远镜所能观测到的更暗、更遥远的天体。

Despite this, 表達脈絡

尽管如此，

Hubble's best images have come and gone, 習語

哈勃最佳图像的时代已经过去，

and the limitations of physics

物理学的限制

will likely stop it from seeing anything dimmer or further than it already has. 語法

可能使它无法再看到比目前所见更暗或更远的东西。

In order to observe the furthest and dimmest objects in the universe,

为了观测宇宙中最远和最暗的天体，

you need an extremely high-resolution telescope

你需要一台超高分辨率的望远镜

and the ability to capture as much light as possible. 語法

以及捕捉尽可能多光线的能力。

The resolution of a telescope is limited to the number of wavelengths it can fit across its mirror.

望远镜的分辨率受到其镜面上能容纳的波长数量的限制。

The angular resolution of a telescope measures its ability to identify two separate objects 用詞

望远镜的角分辨率衡量了它分辨两个独立天体的能力，

that have a short angular distance when observed by a telescope.

这两个天体在被望远镜观测时角距离很小。

This is given by 1.22 multiplied by the wavelength of the light

其计算公式是1.22乘以光波长，

over the diameter of the mirror.

除以镜面直径。

When observing visible light of about 500 nanometers,

当观测大约500纳米的可见光时，

Hubble has an angular resolution of about 0.05 arc seconds.

哈勃的角分辨率约为0.05角秒。

This beats the human eye's resolution by a factor of 1,000. 短語搭配

这比人眼的分辨率高出1000倍。

For even shorter wavelengths like ultraviolet,

对于像紫外线这样更短的波长，

the resolution gets even better,

分辨率甚至会更好，

and Hubble can achieve an angular resolution as low as 0.01 arc seconds. 語法

哈勃可以实现低至0.01角秒的角分辨率。

Hubble is also limited by the types of wavelengths it can observe.

哈勃也受到它能观测的波长类型的限制。

Stars emit a wide range of light,

恒星发出范围很广的光，

and although Hubble can observe a wide range of wavelengths,

尽管哈勃可以观测很宽范围的波长，

it can't observe anything greater than near infrared.

但它无法观测长于近红外线的光。

This limits its ability to look back in time to distant objects. 習語

这限制了它回溯时间观测遥远天体的能力。

As the universe expands,

随着宇宙的膨胀，

the fabric of space expands with it. 習語

空间结构也随之膨胀。

When light travels through the universe,

当光在宇宙中传播时，

its wavelength is stretched with the expansion of space.

它的波长会随着空间的膨胀而被拉长。

This means that by the time the light arrives at Hubble, 語法

这意味着当光线到达哈勃时，

the wavelength of the light is longer than when it left the object.

光的波长比离开天体时更长。

This is known as redshifting. 用詞

这被称为红移。

As the distance to an object increases, 語法

随着天体距离的增加，

the longer its light will spend traveling through space,

它的光在太空中传播的时间就越长，

and the more red-shifted it will get.

它的红移程度也会越大。

If the light is red-shifted too much,

如果光被红移得太多，

it could be stretched to a wavelength outside of Hubble's viewing range.

它可能会被拉长到哈勃观测范围之外的波长。

One of the main goals of the Hubble telescope

哈勃望远镜的主要目标之一

was to find the most distant galaxy in the known universe.

是找到已知宇宙中最遥远的星系。

It achieved this in 2016 when it discovered galaxy GN-z11.

它在2016年发现了GN-z11星系，实现了这一目标。

This galaxy is located 32 billion light-years away, 用詞

这个星系位于320亿光年之外，

and the light we see from it shows the galaxy as it was 13.4 billion years ago. 語法

我们看到来自它的光，展示了该星系134亿年前的模样。

This galaxy is at the very limit of how far into the past Hubble can see,

这个星系处于哈勃能看到过去的最远极限，

and it was discovered due to some incredible circumstances.

而且它的发现要归功于一些令人难以置信的条件。

The galaxy just so happens to be in an area of the universe 短語搭配

这个星系恰好位于宇宙中一个特殊的区域，

where there is very little neutral gas between it and Hubble.

在它和哈勃之间几乎没有中性气体。

This gave the telescope a clear view to observe the galaxy.

这给了望远镜一个清晰的视野来观测这个星系。

The light coming from the galaxy passed by another nearby galaxy,

来自该星系的光线经过了另一个附近的星系，

which caused it to be gravitationally lensed. 用詞

这导致了引力透镜效应。

This happens when the light from an object is bent by the gravitational pull of another object.

当一个天体的光线被另一个天体的引力弯曲时，就会发生这种情况。

Light that would otherwise miss the observer 語法

那些原本会错过观测者的光线

is bent in a way which directs it toward the observer.

发生了弯曲，并射向了观测者。

This caused the light from galaxy GN-z11

这使得来自GN-z11星系的光

to be magnified just enough for Hubble to observe it. 語法

被放大得刚好足以让哈勃观测到它。

So far, 語法

到目前为止，

Hubble has been capturing these stunning images for 29 years.

哈勃捕捉这些令人惊叹的图像已经29年了。

Due to its design,

得益于其设计，

Hubble was capable of being serviced in orbit. 語法

哈勃能够在轨道上进行维修。

Over the years,

多年来，

the space shuttle crew visited Hubble on five separate missions to fix and replace faulty components.

航天飞机机组人员在五次单独的任务中造访哈勃，修理和更换了故障部件。

However, since the shuttle program ended in 2011,

然而，自从航天飞机计划在2011年结束后，

we no longer have the ability to maintain Hubble,

我们就不再具备维护哈勃的能力，

which is starting to take its toll on the telescope. 習語

这开始对这台望远镜产生不利影响。

Hubble has six gyros on board,

哈勃搭载了六个陀螺仪，

which it uses to maneuver and point its telescope precisely toward its target.

它利用这些陀螺仪进行机动并将望远镜精确地指向目标。

In the last 5 years,

在过去的5年里，

three of these gyros have failed.

其中三个陀螺仪已经发生故障。

Even if Hubble continues to function over the next decade, 語法

即使哈勃在未来十年内继续运作，

its orbit is constantly decaying, 用詞

它的轨道也在不断下降，

and in the 2030s,

到了2030年代，

Hubble will crash into the atmosphere and burn up before reaching the ground. 短語動詞

哈勃将会坠入大气层，在落地前燃烧殆尽。

By the time this happens,

到那时，

the next generation of space telescopes will be in orbit,

下一代太空望远镜将会在轨道上运行，

producing even more stunning images of our universe.

拍摄我们宇宙更令人惊叹的图像。

But Hubble's groundbreaking images will never be forgotten.

但哈勃拍摄的开创性图像永远不会被遗忘。

So, although Hubble will be decades old before it retires,

因此，尽管哈勃在退役前将有几十年的历史，

its existence will be a mere flash compared to the age of the objects it's managed to capture. 習語

与它所成功捕捉的天体的年龄相比，它的存在只是一瞬间。

Nevertheless, 表達脈絡

尽管如此，

the incredible engineering and science behind this telescope

这台望远镜背后令人难以置信的工程学和科学

helped us take an enormous step forward in our understanding of the universe. 習語

帮助我们在了解宇宙的道路上迈进了一大步。

Thank you very much for watching,

非常感谢您的观看，

and I'll see you in the next video.

我们下期视频再见。