How small are we in the scale of the universe? - Alex Hofeldt

譯者: Yueh-Lun Huang 審譯者: Seke Wei

In the winter of 1995,

1995 年冬天

scientists pointed the Hubble Telescope at an area of the sky near the Big Dipper,

科學家將哈伯望遠鏡 對準了北斗七星附近的一塊天空

該區域黑暗且沒有周圍恆星的光害

a spot that was dark and out of the way of light pollution from surrounding stars.

這塊區域看似空無一物， 整個觀測存有風險

The location was apparently empty, and the whole endeavor was risky.

What, if anything, was going to show up?

究竟能觀測到什麼？

Over ten consecutive days,

連續十天

the telescope took close to 150 hours of exposure of that same area.

望遠鏡對該地區 曝光了將近 150 小時

And what came back was nothing short of spectacular:

得到的照片，簡直無與倫比

an image of over 1,500 distinct galaxies

照片裡有超過 1,500 個 不同的星系

glimmering in a tiny sliver of the universe.

閃爍在一丁點範圍的宇宙裡

Now, let's take a step back to understand the scale of this image.

現在讓我們回頭理解這張照片的尺度

If you were to take a ballpoint pen

如果你拿起一支原子筆

and hold it at arm's length in front of the night sky,

對著夜空伸長你的手臂

focusing on its very tip,

專注看著原子筆的筆尖

that is what the Hubble Telescope captured in its first Deep Field image.

那就是哈伯望遠鏡 拍攝首張深空照片的範圍

In other words,

換句話說

those 3,000 galaxies were seen in just a tiny speck of the universe,

這 3,000 個星系 只佔宇宙的微小範圍

approximately one two-millionth of the night sky.

大約只佔夜空的兩百萬分之一

To put all this in perspective,

為了弄清楚這一切

the average human measures about 1.7 meters.

人類的平均身高 1.7 公尺

With Earth's diameter at 12,700 kilometers,

地球的直徑 12,700 公里

that's nearly 7.5 million humans lined up head to toe.

相當於 750 萬人躺著 頭腳相連的長度

The Apollo 8 astronauts flew a distance of 380,000 kilometers to the moon.

阿波羅 8 號太空人 航行至月球的距離是 38 萬公里

And our relatively small Sun has a diameter of about 1.4 million kilometers,

而我們相對小的太陽， 其直徑約為 140 萬公里

or 110 times the Earth's diameter.

折合地球直徑的 110 倍

A step further,

更遠一點

the Milky Way holds somewhere between 100 to 400 billion stars,

銀河系擁有一千億至四千億顆恆星

including our Sun.

包括我們的太陽

And each glowing dot of a galaxy captured in the Deep Field image

深空照片拍到的每個發光點

contains billions of stars at the very least.

都至少包含數十億顆恆星

Almost a decade after taking the Deep Field image,

在深空照片拍攝十年後

scientists adjusted the optics on the Hubble Telescope

科學家調整了哈伯望遠鏡的光學系統

and took another long exposure over a period of about four months.

再度進行大約為期四個月的長期曝光

This time, they observed 10,000 galaxies.

這次，他們觀察到一萬個星系

Half of these galaxies have since been analyzed more clearly

至今，已經清楚地分析了其中一半的星系

in what's known as the eXtreme Deep Field image,

這就是所謂的「極深空照片」

or XDF.

或稱 XDF

By combining over ten years of photographs,

將十多年的照片結合起來

the XDF shows galaxies so distant

XDF 顯示出這些星系是如此遙遠

that they're only one ten-billionth the brightness

其亮度只是人眼可以感知程度的

that the human eye can perceive.

百億分之一

所以，我們能從深空照片 學到些宇宙的什麼？

So, what can we learn about the universe from the Deep Field images?

In a study of the universe, space and time are inextricably linked.

在宇宙的研究中，空間與時間密不可分

That's because of the finite speed of light.

這是由於光速有限

So the Deep Field images are like time machines to the ancient universe.

因此，深空照片就像是 時光機回到古代宇宙

They reach so far into space and time

它們回到久遠的時空

that we can observe galaxies that existed over 13 billion years ago.

使我們能觀察到 130 億年以前的星系

這意味著我們現今照片所看的

This means we're looking at the universe as it was

less than a billion years after the Big Bang,

是發生大爆炸後十億年內的宇宙

and it allows scientists to research galaxies in their infancy.

科學家得以能夠研究嬰兒時期的星系

The Deep Field images have also shown that the universe is homogeneous.

深空照片也說明宇宙是均質的

That is, images taken at different spots in the sky look similar.

也就是說，瞄準天空不同的點 所拍攝的照片看起來都很相似

That's incredible when we think about how vast the universe is.

考量宇宙如此遼闊，那尤其不可思議，

Why would we expect it to be the same across such huge distances?

橫跨如此遠距， 何以我們仍預期它是均質的？

On the scale of a galaxy, let alone the universe,

別說宇宙，單以星系尺度來看

we're smaller than we can readily comprehend,

我們比容易理解的事物還要小很多

but we do have the capacity to wonder,

但我們確實有好奇的能力

to question,

去提問

to explore,

去探索

to investigate,

去查證

and to imagine.

並且想像

So the next time you stand gazing up at the night sky,

所以當你下回站著凝視夜空時

take a moment to think about the enormity of what is beyond your vision,

不妨花些時間想想你眼前所見 眾星之間的黑暗處

out in the dark spaces between the stars.

在您視覺之外，隱藏著多廣袤的時空