字幕列表 影片播放
-
The universe began its cosmic life in a big bang
譯者: Lilian Chiu 審譯者: Helen Chang
-
nearly fourteen billion years ago,
宇宙的生命,開始於大爆炸,
-
and has been expanding ever since.
大約發生在 140 億年前,
-
But what is it expanding into?
且從此之後就不斷擴張。
-
That's a complicated question.
但,它會擴張到哪裡去?
-
Here's why:
那是個複雜的問題。
-
Einstein's equations of general relativity
原因如下:
-
describe space and time as a kind of inter-connected
愛因斯坦的廣義相對論方程式
-
fabric for the universe.
把空間和時間描述成
-
This means that what we know of as space and time
一種相互連結的宇宙構造。
-
exist only as part of the universe and not beyond it.
意思就是說,我們對於 空間和時間所知的一切,
-
Now, when everyday objects expand, they move out
都只是宇宙的一部分, 存在於宇宙中,不是宇宙外。
-
into more space.
當日常的物品擴張的時候,
-
But if there is no such thing as space to expand into,
它們會向外移動到更多的空間中。
-
what does expanding even mean?
但如果沒有更多的空間 可以擴張下去,
-
In 1929 Edwin Hubble's astronomy observations
那擴張又是什麼意思呢?
-
gave us a definitive answer.
1929 年,愛德溫哈伯的天文觀察
-
His survey of the night sky found all faraway galaxies
給了我們決定性的答案。
-
recede, or move away, from the Earth.
他對於夜空的調查發現 所有的遙遠銀河
-
Moreover, the further the galaxy, the faster it recedes.
都會後退,或是說遠離地球。
-
How can we interpret this?
此外,越遠的銀河, 後退的速度越快。
-
Consider a loaf of raisin bread rising in the oven.
我們要如何詮釋這項觀察?
-
The batter rises by the same amount in between each
想想看,有一條葡萄乾 麵包在爐中發酵。
-
and every raisin.
麵糊的發酵依據的就是
-
If we think of raisins as a stand-in for galaxies,
每兩個葡萄乾之間的量。
-
and batter as the space between them,
如果我們把葡萄乾比喻成銀河,
-
we can imagine that the stretching or expansion
麵糊是銀河之間的空間,
-
of intergalactic space will make the galaxies recede from each other,
我們就可以想像, 兩個銀河之間的空間
-
and for any galaxy, its faraway neighbors will recede a larger
若延伸或擴張,就會讓 這兩個銀河退開遠離彼此,
-
distance than the nearby ones
對任何銀河而言,在同樣的 時間內,比起相近的鄰居,
-
in the same amount of time.
遙遠的鄰居會退開的 距離就比較大。
-
Sure enough, the equations of general relativity predict a cosmic
當然,廣義相對論的方程式預測
-
tug-of-war between gravity and expansion.
在引力和擴張之間 會發生宇宙拔河。
-
It's only in the dark void between galaxies where expansion wins out,
只有在銀河之間的黑暗空間內,
-
and space stretches.
擴張才會勝出,空間才會延伸。
-
So there's our answer.
所以,我們的答案是:
-
The universe is expanding unto itself.
宇宙會擴張到它自己裡面。
-
That said, cosmologists are pushing the limits of mathematical models
然而,宇宙學家還在 將數學模型的極限向外推,
-
to speculate on what, if anything, exists beyond our spacetime.
來推斷在我們的空間時間之外 有什麼存在(如果有的話)。
-
These aren't wild guesses, but hypotheses that tackle
這些不是瞎猜, 而是假設,為了處理
-
kinks in the scientific theory of the Big Bang.
大爆炸科學理論中的 扭曲而做的假設。
-
The Big Bang predicts matter to be distributed evenly across the universe,
大爆炸預測物質會平均地 分佈到整個宇宙,
-
as a sparse gas --but then, how did galaxies and stars come to be?
以稀疏氣體的形式散播,
-
The inflationary model describes a brief era
但,這樣的話,銀河 和星星又是怎麼生成的?
-
of incredibly rapid expansion
膨脹模型就描述了
-
that relates quantum fluctuations in the energy of the early universe,
一個非常快速擴張的簡短時代,
-
to the formation of clumps of gas that eventually led to galaxies.
讓早期宇宙能量中的 量子擾動與氣體塊的形成
-
If we accept this paradigm, it may also imply our universe represents
拉上關係,最終, 這些氣體塊造成了銀河。
-
one region in a greater cosmic reality that undergoes endless, eternal inflation.
如果我們接受這個範式, 那可能也意味著我們的宇宙代表
-
We know nothing of this speculative inflating reality,
一個更大的宇宙現實 當中的一個區域,
-
save for the mathematical prediction that its endless expansion
而這個更大的宇宙正在 經歷無盡、永恆的膨脹。
-
may be driven by an unstable quantum energy state.
我們完全不了解這個 推測出來的膨脹現實,
-
In many local regions, however, the energy may settle by random
我們只有數學預測, 預測這無止境的擴張
-
chance into a stable state, stopping inflation and forming bubble universes.
可能是由一個不穩定的 量子能量狀態所驅動的。
-
Each bubble universe —ours being one of them
然而,在許多當地的區域, 能量可能會隨機地安頓下來,
-
—would be described by its own Big Bang and laws of physics.
進入穩定的狀態,不再膨脹, 也不再形成泡泡宇宙。
-
Our universe would be part of a greater multiverse,
每一個泡泡宇宙—— 我們的宇宙是其中之一——
-
in which the fantastic rate of eternal inflation makes it impossible
可以用它自己的大爆炸 和物理法則來描述。
-
for us to encounter a neighbor universe.
我們的宇宙只是更大的 多重宇宙的一部分,
-
The Big Bang also predicts that in the early, hot universe, our fundamental forces
在多重宇宙中, 永恆膨脹的驚人速度
-
may unify into one super-force.
讓我們沒機會遇到 任何一個鄰接的宇宙。
-
Mathematical string theories suggest descriptions of this unification,
大爆炸也預測,在早期高溫的 宇宙中,我們的基本「力」
-
in addition to a fundamental structure for sub-atomic quarks and electrons.
可能會統一成一股超級力。
-
In these proposed models, vibrating strings are the building blocks of the universe.
數學弦理論中,除了亞原子夸克
-
Competing models for strings have now been consolidated into a unified description,
和電子的基礎結構之外, 也描述了這種統一。
-
and suggest these structures may interact with massive, higher dimensional surfaces called branes.
在這些被提出的模型中, 震動的弦是建造宇宙的積木。
-
Our universe may be contained within one such brane,
其他競爭的弦模型現在已經 被整合成了統一的描述,
-
floating in an unknown higher dimensional place, playfully named “the bulk,” or hyperspace.
指出這些結構 可能會和「膜」互相影響,
-
Other branes—containing other types of universes—may co-exist in hyperspace,
膜就是更高質量高維度的表面。
-
and neighboring branes may even share certain fundamental forces like gravity.
我們的宇宙可能就是 在一個這樣的膜當中,
-
Both eternal inflation and branes describe a multiverse,
漂浮在一個更高維度的未知之地,
-
but while universes in eternal inflation are isolated, brane universes could bump into each other.
它有個有趣的名字 叫「體」,或超空間。
-
An echo of such a collision may appear in the cosmic microwave background
其他的膜—— 內含其他類型的宇宙——
-
—a soup of radiation throughout our universe, that's a relic from an early Big Bang era.
可能也共同存在於超空間中,
-
So far, though, we've found no such cosmic echo.
而相鄰的膜可能還會共享 某些基礎的力,比如引力。
-
Some suspect these differing multiverse hypotheses may eventually coalesce into a common description,
永恆的膨脹以及膜, 都是在描述一個多種宇宙,
-
or be replaced by something else.
但,雖然永恆膨脹的 宇宙是孤立的,
-
As it stands now, they're speculative explorations of mathematical models.
膜宇宙則有可能會相撞。
-
While these models are inspired and guided by many scientific experiments,
每一次這類的碰撞的回響都可能會 出現在宇宙微波背景中——
-
there are very few objective experiments to directly test them, yet.
也就是從早期大爆炸時殘留下來, 遍及我們的整個宇宙中的輻射。
-
Until the next Edwin Hubble comes along,
不過,目前我們還沒有 找到這種宇宙回響。
-
scientists will likely be left to argue about the elegance of their competing models…
有些人懷疑 這些不同的多種宇宙假設
-
and continue to dream about what, if anything, lies beyond our universe.
最終可能會結合成一個共同假設,