【Retell Lecture】宇宙为什么是黑的？宇宙究竟有多大？一起来探索下宇宙的奥秘！原来人类已经走了这么远！,IPENGLISH黄老师微信公众号文章

听说关注了IPENGLISH的同学都考到了高分哦

Retell Lecture

黄威老师

雅培英语名师

机经积累的重要性

今天为大家带来的是Retell Lecture的一篇文章：Galaxy Darkness - why is it in space ? 该篇文章没有一个确切的文本/音频，网上流传的机经也各不相同。

该文章的核心思路为：因为宇宙太大了，横行的光芒不足以照亮整个宇宙，所以宇宙整体上来说是黑暗的。

关于PTE的RL/SST/SWT的机经，很多题目并没有原文；黄老师会在随后的日子里每周整理出一些有趣背景信息，同学们可以平日进行积累，这样考试的时候听到类似知识点不至于手无足措！

回到今天的话题，宇宙到底有多大？

这里我们可以一起来看一下YouTube一个非常有名的频道《RealLifeLore - How the Universe is Way Bigger Than You Think》(视频链接在文章最后）

我们先来看看离我们最近的火星，它离我们的距离是200M km - 400M km，当人类降落在火星上的时候，他离地球的距离会比月球要远986倍。

Whenever humanity finally gets around to landing a human on a planet, that person will be 986 times further away from Earth than the astronauts who landed on the moon were. （下列文字均为音频原文）

而当火星上的人要发送信号回地球时，信号传输的时间需要花20分钟。

the time delay for sending a message from Mars back to Earth is actually like 20 minutes each direction, which would render instant communication in an event of emergency impossible.

而人类最远的物体现在在哪呢？

Voyager 1太空探测器为人类目前最远的物体，它现在离地球为138个天文学单位

(一个天文学单位是地球到太阳的距离约为火星到地球最近距离的三倍)

when we zoom out even further away we can find the voyager 1 space probe, which is the furthest away man-made object from Earth, it is currently located 138 AU’s from The Earth. AU meaning astronomical unit, which is the distance between the Earth and the Sun.

在旅程中，Voyager 1拍摄了一张照片。也就是上面这张，这张照片看起来并没有那么特殊，但它可是人类史上最伟大的照片！

上图中的那个灰色小点，就是我们所在的地球，所有你认识的人，发生过的事情，正在经历的喜剧和悲剧，就发生在那个不起眼的小点上。

As some point on its long voyage, Voyager 1 turned its camera around and took this photograph, it may not look like much at first, but this is the greatest single photograph ever taken in all of human history. This tiny pale blue dot is earth, and I don’t think anybody has ever said something amazing about this as Carl Sagan when he said, if you look at it, you see a dot.

That’s here, that’s home, that’s us. On it, everyone you ever heard of, every human being who ever lived, lived out their lives. Every hero and coward. Every creator and destroyer of civilizations. Every king and every peasant. Every saint and sinner in the history our species lived there, on a mote of dust suspended in a sunbeam.

而Voyager 1还需要花足足三万年才能离开太阳系！