英文翻译：地球位于星系中的什么位置？

你可能听过这句话:“一切都是相对的”。当你考虑我们在宇宙中的位置这个问题时,一切也都是相对的。我在太平洋,加拿大西海岸,温哥华岛记录这一切。我所处的位置距离地球中心大约6370公里那么远。

从我的角度看,太阳就在那边,有如1角硬币大小,似乎触手可及。但它距离我其实非常非常遥远。实际上,在这个具体时间里,太阳比我肉眼所看到的任何物体都更遥远。我与太阳的距离大约是1亿5000万公里,你与它的距离也是一样。

我们正在刻画一个椭圆形轨道,地球在这个轨道上完成一次完整的旅程需要整整一年的时间。你,我和地球都位于太阳系里。太阳系包含了太阳,8颗行星以及巨量的冰、岩石和尘埃的集合。我们位于我们的星系、银河系的深处。这个巨大的扁平盘面星系,直径高达12万光年。

我们的太阳系位于银盘的中央。说到中央,我指的是星系中心大约2万7千光年那么远的位置,距离银河系的边缘也是同样那么远的距离。

我们的银河系只是更大的星系集合,称为本星系群中的星系之一。在本星系群中有36个著名天体。大多数是矮星系。也有三角座星系、银河系和仙女座星系,仙女座星系是迄今为止本星系群中体积最大、质量最重的天体,它的体积是银河系的2倍,质量是银河系的4倍。

但是,它在哪里?

对你我来说,仙女座星系距离我们如天文数字般遥远,250万光年那么远。或者说,仙女座距离我们只有短短的250万光年那么远?我为什么这样说呢,往下看你就明白了。

本星系群又属于范围更大的室女座超星系团,室女座超星系团包含约100个星系群与星系团。这个超星系团大概的中心位置是处女座。截至目前,距离我们6500万光年那么远。这令250光年的仙女座看起来就像开着家庭轿车,花一下午的时间就能到达的短途旅行。

不出所料,室女座超星系团也是更大星系结构的一部分,双鱼-鲸鱼座超星系团复合体。这是一个大尺度纤维状结构的巨大超星系团,大约是10亿光年长,1亿5千万光年宽。中心位置也就在那边,就那么远。

10亿光年的长度?这样仙女座看起来似乎近在咫尺。那我们在哪里呢?在整个宇宙中,你、我还有地球处于什么位置呢?可观测宇宙的边缘有138亿光年那么远。

宇宙学家认为,如果你沿着任意方向出发,旅行的时间足够长,那么你最终会回到起点,就像你在地球表面任意方向出发一样,最后都能回到起点。换句话说,地球位于宇宙最中心的位置。这听起来很神奇。

对你、我来说,正位于宇宙的中心,这是多么奇妙的巧合啊。正中央。不偏不倚,正好位于宇宙中心。这让我们觉得自己很重要,对不对?但是,就宇宙中的每一个点而言,也都是宇宙的中心。

你没有听错。你能想象到宇宙中的每一个地方也是宇宙的中心。从普遍相关性来看,这无疑让我们觉得问题更复杂了。所有这一切分析确实让我们觉得我们与仙女座更接近了…,但其实它仍在那里,在宇宙的中心。

以下为英文原文：

Where is Earth located in the galaxy?

You've probably heard the saying "everything's relative". When you consider our place in the Universe, everything really is relative. I'm recording this halfway up Vancouver Island, in the Pacific Ocean, off the West Coast of Canada. And where I'm standing is about 6,370 kilometers away from the center of the Earth, that way.

From my perspective, the Sun is over there. It's as large as a dime held at arm's length. For me it's really, really far away. In fact, at this exact time it's further away than any object I you can see with the naked eye.I'm about 150 million kilometers away from the Sun, and so are you.

We're carving out an elliptical orbit which takes one full year to complete one whole trip around. You, me and the Earth are all located inside our Solar System. Which contains the Sun, 8 planets and a vast collection of ice, rocks and dust. We're embedded deep within our galaxy, the Milky Way. It's a big flat disk of stars measuring up to 120,000 light years across.

Our Solar System is located in the middle of this galactic disk. And by the middle, I mean the center of the galaxy is about 27,000 light years that way, and the edge of the galaxy is about the same distance that way.

Our Milky Way is but one galaxy in a larger collection of galaxies known as the Local Group. There are 36 known objects in the local group. Which are mostly dwarf galaxies. However, there's also the Triangulum Galaxy, the Milky Way, and the Andromeda galaxy… which is by far the largest, most massive object in the Local Group, It's twice the size and 4 times the mass of the Milky Way.

But where is it?

From me, and you, Andromeda is located just an astronomically distant 2.5 million light years that way. Or would that be just short 2.5 million light-years that away? I'm sure you see where this is going.

The Local Group is embedded within a much larger group known as the Virgo Supercluster, containing at least 100 galaxy groups and clusters. The rough center of the supercluster is in the constellation Virgo. Which as of right now, is that way, about 65 million light years away. Which certainly makes the 2.5 million light years to Andromeda seem like an afternoon jaunt in the family car.

Unsurprisingly, The Virgo Supercluster is a part of a larger structure as well. The Pisces-Cetus Supercluster Complex. This is a vast filament of galactic superclusters measuring about 150 million light years across AND a billion light years long. The middle is just over that way. Right over there.

One billion light years in length? Well that makes Andromeda seem right around the corner. So where are we? Where are you, and I and the Earth located in the entire Universe? The edge of the observable Universe is about 13.8 billion light years that way. But it's also 13.8 billion light years that way. And that way, and that way.

And cosmologists think that if you travel in any direction long enough, you'll return to your starting point, just like how you can travel in any one direction on the surface of the Earth and return right back at your starting point. In other words, the Earth is located at the very, very center of the Universe. Which sounds truly amazing.

What a strange coincidence for you and I to be located right here. Dead center. Smack dab right in the middle of the Universe. Certainly makes us sound important doesn't it? But considering that every other spot in the Universe is also located at the center of the universe.

You heard me right. Every single spot that you can imagine inside the Universe is also the center of the Universe. That definitely complicates things in our plans for Universal relevance. And all this sure does make Andromeda seem close by….and it's still just right over there, at the center of the Universe.