A few months ago the Nobel Prize in physics was awarded to two teams of astronomers for a discovery that has been hailed as one of the most important astronomical observations ever. And today, after briefly describing what they found, I'm going to tell you about a highly controversial framework for explaining their discovery, namely the possibility that way beyond the Earth, the Milky Way and other distant galaxies, we may find that our universe is not the only universe, but is instead part of a vast complex of universes that we call the multiverse.
幾個月前, 兩個天文學家的團隊, 因為他們所作出的一個 被稱為天文觀測史上 最重要的觀察之一, 而獲得了諾貝爾物理學獎。 而今天,在簡短的描述他們的發現之後, 我將告訴你們一個可以解釋他們的發現, 但卻非常有爭議的理論架構。 那就是, 在超出地球, 超出銀河系和一切遙遠的星系以上, 我們可能會明白我們的宇宙 并不是唯一的宇宙, 而只是一個極度龐大的宇宙群, 我們所謂的多元宇宙, 其中的一個。
Now the idea of a multiverse is a strange one. I mean, most of us were raised to believe that the word "universe" means everything. And I say most of us with forethought, as my four-year-old daughter has heard me speak of these ideas since she was born. And last year I was holding her and I said, "Sophia, I love you more than anything in the universe." And she turned to me and said, "Daddy, universe or multiverse?" (Laughter)
多元宇宙的想法有些奇怪。 我們大多數人在成長中都被教予 “宇宙”這個詞代表著所有的一切。 我說“我們大多數”是經過考慮的, 因為我的四歲的女兒從出生便開始聽我說這些想法, 而去年當我抱住她 然後我對她說: “索菲亞, 我愛你超過宇宙中所有的一切。” 然後她轉過來對我說, “爸爸, 是宇宙還是多元宇宙?” (笑聲)
But barring such an anomalous upbringing, it is strange to imagine other realms separate from ours, most with fundamentally different features, that would rightly be called universes of their own. And yet, speculative though the idea surely is, I aim to convince you that there's reason for taking it seriously, as it just might be right. I'm going to tell the story of the multiverse in three parts. In part one, I'm going to describe those Nobel Prize-winning results and to highlight a profound mystery which those results revealed. In part two, I'll offer a solution to that mystery. It's based on an approach called string theory, and that's where the idea of the multiverse will come into the story. Finally, in part three, I'm going to describe a cosmological theory called inflation, which will pull all the pieces of the story together.
但在這反常的教育以外, 設想和我們的世界 分離的領域還是很奇怪, 它們或許有著從根本上完全不同的特徵, 并各自可以被稱作宇宙。 但是,雖然 這個設想只是推測, 我的目標是說服你們 的確有理由來認真的考慮它, 因為它有可能就是真的。 我將把多元宇宙的故事分成三部份。 在第一部份, 我將描述那獲得諾貝爾獎的研究結果, 以及這些結果揭發的 一個意義深遠的謎團。 在第二部份, 我將為那個謎團提出一個解釋。 它基於一個叫做弦理論的方法, 並會將多元宇宙的概念 來引進這個故事中。 最終,在第三部份, 我將描述一個叫做“暴脹”的 宇宙論, 而它將把故事所有的片段聯繫在一起。
Okay, part one starts back in 1929 when the great astronomer Edwin Hubble realized that the distant galaxies were all rushing away from us, establishing that space itself is stretching, it's expanding. Now this was revolutionary. The prevailing wisdom was that on the largest of scales the universe was static. But even so, there was one thing that everyone was certain of: The expansion must be slowing down. That, much as the gravitational pull of the Earth slows the ascent of an apple tossed upward, the gravitational pull of each galaxy on every other must be slowing the expansion of space.
好的。 第一部份從1929年開始。 著名的天文學家愛德文.哈伯 發現遠處的星系 都在迅速的離我們遠去, 說明了空間本身正在伸展, 在擴張。 而這是突破性的。 當時普遍的認知是,在最大的範圍內, 宇宙是靜止的。 但即使如此, 有一件事情是所有人都確信的: 擴張必定在逐漸緩慢下來。 就像地球上的萬有引力 將往上拋的蘋果的速度慢下來, 每一個星系對對方的 萬有引力 必定也在將空間的擴張 緩慢下來。
Now let's fast-forward to the 1990s when those two teams of astronomers I mentioned at the outset were inspired by this reasoning to measure the rate at which the expansion has been slowing. And they did this by painstaking observations of numerous distant galaxies, allowing them to chart how the expansion rate has changed over time. Here's the surprise: They found that the expansion is not slowing down. Instead they found that it's speeding up, going faster and faster. That's like tossing an apple upward and it goes up faster and faster. Now if you saw an apple do that, you'd want to know why. What's pushing on it?
現在讓我們快轉到90年代, 當我在一開始講到的 那兩個天文學家的團隊 受到了這個推理的啟迪, 來測量宇宙擴張 減慢的速度。 他們 對很多個遠處星系 做出的縝密的觀察 允許他們記錄下來 宇宙隨著時間過去,擴張速度的變化 而令人吃驚的事情發生了: 他們發現擴張并沒有緩緩減速。 相反,他們發現它正在加速, 越來越快。 這就像將一個蘋果拋上空中, 然後它往上的速度越來越快。 如果你看到一個蘋果那樣表現的話, 你會想知道這是爲什麽。 是什麽東西在推動著它?
Similarly, the astronomers' results are surely well-deserving of the Nobel Prize, but they raised an analogous question. What force is driving all galaxies to rush away from every other at an ever-quickening speed? Well the most promising answer comes from an old idea of Einstein's. You see, we are all used to gravity being a force that does one thing, pulls objects together. But in Einstein's theory of gravity, his general theory of relativity, gravity can also push things apart.
同樣的,這些天文學家的結果 肯定應該獲得諾貝爾獎, 但它們也提起了一個相似的問題。 是什麽力量在將 所有的星系往外 以越來越快的速度推動? 最好的答案 源於愛因斯坦的一個老想法。 你看,我們都習慣於萬有引力 只做一件事情, 那就是將事物拉到一起。 但在愛因斯坦的萬有引力理論, 它的廣義相對論中, 萬有引力也可以將事物推開。
How? Well according to Einstein's math, if space is uniformly filled with an invisible energy, sort of like a uniform, invisible mist, then the gravity generated by that mist would be repulsive, repulsive gravity, which is just what we need to explain the observations. Because the repulsive gravity of an invisible energy in space -- we now call it dark energy, but I've made it smokey white here so you can see it -- its repulsive gravity would cause each galaxy to push against every other, driving expansion to speed up, not slow down. And this explanation represents great progress.
這是如何做到的?根據愛因斯坦的計算, 如果空間被一種 無形的能量均勻的佔據, 就像一個均勻的,無形的迷霧, 那麼這個迷霧產生的引力 將會是相斥的, 而相斥的引力 恰恰可以提我們解釋這些觀察結果。 因為空間中一種無形的能量 產生的相斥的引力 - 我們現在叫它暗能量, 但我在這裡將它變成煙霧般的白色讓你能看到 - 它的相斥的引力 會導致每一個星系互相推動, 將擴張速度變快, 而不是變慢。 而這個解釋 代表著很大的進展。
But I promised you a mystery here in part one. Here it is. When the astronomers worked out how much of this dark energy must be infusing space to account for the cosmic speed up, look at what they found. This number is small. Expressed in the relevant unit, it is spectacularly small. And the mystery is to explain this peculiar number. We want this number to emerge from the laws of physics, but so far no one has found a way to do that.
但我答應了你在第一部份 有一個謎團。 謎題是如此的: 當這些天文學家計算出 空間中需要 多少暗能量 才能導致現在的宇宙擴張加速, 看看他們所發現的。 這個數字很小。 以相應的單位时表示, 它令人吃驚地小。 而謎團便是如何解釋這個古怪的數字。 我們想讓這個數字 從物理定律中自然的浮現, 但目前為止沒有人知道如何做。
Now you might wonder, should you care? Maybe explaining this number is just a technical issue, a technical detail of interest to experts, but of no relevance to anybody else. Well it surely is a technical detail, but some details really matter. Some details provide windows into uncharted realms of reality, and this peculiar number may be doing just that, as the only approach that's so far made headway to explain it invokes the possibility of other universes -- an idea that naturally emerges from string theory, which takes me to part two: string theory.
現在你可能在想, 這是你應該關心的嗎? 或許解釋這個數字 只是一個技術上的問題, 一個專家對之有興趣的技術細節, 但對其他人來說沒有任何意義。 它的確是一個技術細節, 但有些細節真的狠重要。 有些細節可以為 探索未知的現實提供一扇窗。 而這個特殊的數字很有可能就是這扇窗, 因為到目前為止,唯一一個可以解釋它的方法 包括了其他宇宙的存在的可能 - 一個從弦理論中自然而然浮現的理念, 而從這裡我開始講第二部份: 弦理論。
So hold the mystery of the dark energy in the back of your mind as I now go on to tell you three key things about string theory. First off, what is it? Well it's an approach to realize Einstein's dream of a unified theory of physics, a single overarching framework that would be able to describe all the forces at work in the universe. And the central idea of string theory is quite straightforward. It says that if you examine any piece of matter ever more finely, at first you'll find molecules and then you'll find atoms and subatomic particles. But the theory says that if you could probe smaller, much smaller than we can with existing technology, you'd find something else inside these particles -- a little tiny vibrating filament of energy, a little tiny vibrating string. And just like the strings on a violin, they can vibrate in different patterns producing different musical notes. These little fundamental strings, when they vibrate in different patterns, they produce different kinds of particles -- so electrons, quarks, neutrinos, photons, all other particles would be united into a single framework, as they would all arise from vibrating strings. It's a compelling picture, a kind of cosmic symphony, where all the richness that we see in the world around us emerges from the music that these little, tiny strings can play.
請將神秘的暗能量 暫時放在腦後, 因為我將告訴你 關於弦理論的三個關鍵的事情。 首先,弦理論是什麽? 它是一個可以完成愛因斯坦的夢想, 一個統一的物理理論的方法, 一個可以形容 宇宙中所有運行的力的 全面的思想架構。 而弦理論的中心思想 很直接明瞭。 它說,如果你近乎無限仔細的考察 任何一個物質, 一開始你會發現分子, 然後你會發現原子和次原子微粒。 但弦理論說,如果你能夠在探查的更細微一些, 比任何我們現在擁有的科技可以做到的都細微, 你會發現在這些微粒中還有東西 -- 一個很小的,振動的能量絲, 一個很小的,振動的弦。 而就像一個小提琴的琴弦一樣, 它們可以以不同的頻率振動, 產生不同的音調。 這些小的基礎的弦們, 當它們以不同的頻率振動的時候, 它們會產生不同的微粒, 比如電子,夸克,中微子,光子, 以及所有的其他的微粒 都會被統一在一個體系之下, 因為他們都由振動的弦構成。 這是一個非常扣人心弦的構想, 一種星雲交響曲, 我們所看到周圍的 這個世界上的富饒的一切, 都在這些細小的弦的 演奏中形成。
But there's a cost to this elegant unification, because years of research have shown that the math of string theory doesn't quite work. It has internal inconsistencies, unless we allow for something wholly unfamiliar -- extra dimensions of space. That is, we all know about the usual three dimensions of space. And you can think about those as height, width and depth. But string theory says that, on fantastically small scales, there are additional dimensions crumpled to a tiny size so small that we have not detected them. But even though the dimensions are hidden, they would have an impact on things that we can observe because the shape of the extra dimensions constrains how the strings can vibrate. And in string theory, vibration determines everything. So particle masses, the strengths of forces, and most importantly, the amount of dark energy would be determined by the shape of the extra dimensions. So if we knew the shape of the extra dimensions, we should be able to calculate these features, calculate the amount of dark energy.
但這個優美的統一理論 有著一個代價, 因為多年的研究 表明了弦理論的數學不怎麼貫通。 它有著內在的矛盾, 除非我們考慮 一個我們完全不熟悉的東西 -- 額外的空間維度。 我們每個人都知道常見的三個空間維度。 而你也可以將它們想成 高度,寬度,和長度。 但弦理論說,在極度小的比例上, 存在著額外的維度, 縮小到了我們還無法 測試到的地步。 但雖然那些維度被隱藏著, 它們對於我們可以觀察的東西有著一定的影響, 因為這些額外的維度的形狀 決定了弦們如何振動。 而在弦理論中, 振動決定一切。 所以微粒質量,力的力度, 以及最重要的,暗能量的數量 都會由這些額外的維度的 形狀決定。 而如果我們知道了這些額外維度的形狀, 我們應該可以計算這些特徵, 計算暗能量的數量。
The challenge is we don't know the shape of the extra dimensions. All we have is a list of candidate shapes allowed by the math. Now when these ideas were first developed, there were only about five different candidate shapes, so you can imagine analyzing them one-by-one to determine if any yield the physical features we observe. But over time the list grew as researchers found other candidate shapes. From five, the number grew into the hundreds and then the thousands -- A large, but still manageable, collection to analyze, since after all, graduate students need something to do. But then the list continued to grow into the millions and the billions, until today. The list of candidate shapes has soared to about 10 to the 500.
我們的挑戰是, 我們并不知道 這些額外維度的形狀。 我們只知道 一些數學允許的 候選形狀。 當這些想法第一次被發展出來的時候, 候選的形狀只有五個左右, 所以你會覺得 將它們一個一個的分析 來決定是否有一個可以產生 我們觀察到的物理特徵。 但隨著研究人員不斷的找到其他的候選形狀 數量不斷的在增加。 它的數字從五個增長到幾百個甚至幾千個 -- 一個雖然龐大,但仍然可以處理和分析的數字, 因為不管如何, 研究博士生們總需要些事情做。 但這個清單繼續增長 到了百萬甚至今天的數十億。直到今天, 候選形狀的清單 百億從猛增到了萬億。
So, what to do? Well some researchers lost heart, concluding that was so many candidate shapes for the extra dimensions, each giving rise to different physical features, string theory would never make definitive, testable predictions. But others turned this issue on its head, taking us to the possibility of a multiverse. Here's the idea. Maybe each of these shapes is on an equal footing with every other. Each is as real as every other, in the sense that there are many universes, each with a different shape, for the extra dimensions. And this radical proposal has a profound impact on this mystery: the amount of dark energy revealed by the Nobel Prize-winning results.
現在該怎麼辦? 有一些研究人員失去了信心, 覺得因為額外維度有著如此之多的候選形狀, 每一個又可能產生不同的物理特徵, 弦理論永遠也不可能做出 確定的,可測試的預測。 但其他人決定從問題的源頭開始, 回到一個多元宇宙的可能。 想法是這樣的。 或許這些形狀的每一個都是與其他的形狀平等的。 每一個都是真實的, 這意味著 有著很多的宇宙, 每一個都有著不同形狀的額外維度。 這一個重大的提論 對於這個謎題有著深遠的影響: 關於著那得了諾貝爾獎的暗能量的數量。
Because you see, if there are other universes, and if those universes each have, say, a different shape for the extra dimensions, then the physical features of each universe will be different, and in particular, the amount of dark energy in each universe will be different. Which means that the mystery of explaining the amount of dark energy we've now measured would take on a wholly different character. In this context, the laws of physics can't explain one number for the dark energy because there isn't just one number, there are many numbers. Which means we have been asking the wrong question. It's that the right question to ask is, why do we humans find ourselves in a universe with a particular amount of dark energy we've measured instead of any of the other possibilities that are out there?
因為 如果有著其他的宇宙, 以及如果那些宇宙每一個的額外維度 都有一個不同的形狀 那麼每一個宇宙的物理特徵就會不同, 而特別的, 每一個宇宙的暗能量的數量 就會不一樣。 這意味著解釋 我們測量的暗能量的古怪數量 會有著一個完全不同的意義。 在這種情況下, 物理定律不會能解釋暗能量的一個數字, 因為不止有一個數字, 反而有很多。 這意味著 我們一路以來都問錯了問題。 對的問題應該是, 爲什麽我們人類會在 一個有著特定的數量的暗能量的宇宙, 而不再外面存在的無數的 其他可能之中?
And that's a question on which we can make headway. Because those universes that have much more dark energy than ours, whenever matter tries to clump into galaxies, the repulsive push of the dark energy is so strong that it blows the clump apart and galaxies don't form. And in those universes that have much less dark energy, well they collapse back on themselves so quickly that, again, galaxies don't form. And without galaxies, there are no stars, no planets and no chance for our form of life to exist in those other universes.
而這個問題我們可以嘗試解決。 因為在那些有著 比我們更多的暗能量的宇宙中, 每當物質試圖凝聚成星系的時候, 暗能量所產生的相斥力量會強大到 將凝聚的物質爆開, 以致星系無法形成。 而在那些有著比我們少的暗能量的宇宙中, 他們的崩塌的速度會快到 使星系無法形成。 而沒有星系的話,恒星和行星也不會形成, 也不可能會有 像我們這樣的生命 存在於那些宇宙當中。
So we find ourselves in a universe with the particular amount of dark energy we've measured simply because our universe has conditions hospitable to our form of life. And that would be that. Mystery solved, multiverse found. Now some find this explanation unsatisfying. We're used to physics giving us definitive explanations for the features we observe. But the point is, if the feature you're observing can and does take on a wide variety of different values across the wider landscape of reality, then thinking one explanation for a particular value is simply misguided.
所以我們所在的宇宙有一個 特定數量的暗能量 僅僅因為我們的宇宙有著可以讓 我們這種生命發展的條件。 就是這樣。 秘密被揭開了。 多元宇宙也找到了。 有些人對這種解釋很不滿意。 我們都習慣于物理 為我們觀察到的東西給予確定的解釋。 但其實 如果一個你觀察到的特性 可以或者的確 在不同的現實中有著 很多不同的數值, 那麼只想著給予其中一個數值 一種解釋 未免誤入歧途了。
An early example comes from the great astronomer Johannes Kepler who was obsessed with understanding a different number -- why the Sun is 93 million miles away from the Earth. And he worked for decades trying to explain this number, but he never succeeded, and we know why. Kepler was asking the wrong question.
一個早期的例子 來自于偉大的天文學家約翰內斯。開普勒。 他癡迷于試圖瞭解 一個不同的數字 -- 爲什麽太陽離地球有九千三百萬英里? 他花了幾十年來解釋這個數字, 但他從未成功,而我們知道爲什麽。 開普勒問了 一個錯的問題。
We now know that there are many planets at a wide variety of different distances from their host stars. So hoping that the laws of physics will explain one particular number, 93 million miles, well that is simply wrongheaded. Instead the right question to ask is, why do we humans find ourselves on a planet at this particular distance, instead of any of the other possibilities? And again, that's a question we can answer. Those planets which are much closer to a star like the Sun would be so hot that our form of life wouldn't exist. And those planets that are much farther away from the star, well they're so cold that, again, our form of life would not take hold. So we find ourselves on a planet at this particular distance simply because it yields conditions vital to our form of life. And when it comes to planets and their distances, this clearly is the right kind of reasoning. The point is, when it comes to universes and the dark energy that they contain, it may also be the right kind of reasoning.
我們現在知道宇宙中有很多行星 和他們的恒星有著完全不同的距離。 所以希望物理定律 能解釋一個特別的數字,九千三百萬英里, 也是誤入了歧途。 反而,正確的問題應該是, 爲什麽我們人類存在在一個離恒星 剛好這麼遠的一個距離上的行星中, 而不在任何其他一個可能中? 再一次,這個問題我們可以回答。 那些離像太陽一樣的恒星太近的行星 會熱的 讓我們這種生命無法生存。 而那些離恒星太遠的行星 又冷到 讓我們這種生命無法形成。 所以我們才會在一個 離恒星有著特定的距離的行星上, 僅僅因為它製造出 對於我們這種生命必須的環境。 而對於行星和距離來說, 這明顯是一個對的邏輯。 我的意思是, 當說到宇宙和它所包含的暗能量, 這也有可能是對的邏輯。
One key difference, of course, is we know that there are other planets out there, but so far I've only speculated on the possibility that there might be other universes. So to pull it all together, we need a mechanism that can actually generate other universes. And that takes me to my final part, part three. Because such a mechanism has been found by cosmologists trying to understand the Big Bang. You see, when we speak of the Big Bang, we often have an image of a kind of cosmic explosion that created our universe and set space rushing outward.
當然,最重要的不同點在於 我們知道外面有著其他的星球, 但到目前為止我們只能猜測 有其他宇宙的可能性。 所以讓它合理化的話, 我們需要一個 可以產生其他宇宙的機制。 而這帶我們來到了第三也是最後一部份。 因為這個機制被研究大爆炸的 宇宙學家發現了。 你看,當我們講大爆炸的時候, 我們經常會想到 一種類似于星雲爆裂 而造成空間不停的擴張的 產生宇宙的方法。
But there's a little secret. The Big Bang leaves out something pretty important, the Bang. It tells us how the universe evolved after the Bang, but gives us no insight into what would have powered the Bang itself. And this gap was finally filled by an enhanced version of the Big Bang theory. It's called inflationary cosmology, which identified a particular kind of fuel that would naturally generate an outward rush of space. The fuel is based on something called a quantum field, but the only detail that matters for us is that this fuel proves to be so efficient that it's virtually impossible to use it all up, which means in the inflationary theory, the Big Bang giving rise to our universe is likely not a one-time event. Instead the fuel not only generated our Big Bang, but it would also generate countless other Big Bangs, each giving rise to its own separate universe with our universe becoming but one bubble in a grand cosmic bubble bath of universes.
但這裡面哪有一個小小的秘密。 大爆炸理論沒有包括一個非常重要的東西, 那就是爆炸的時候。 它告訴我們宇宙是如何在爆炸以後產生的, 但不告訴我們 什麽東西產生了爆炸。 而這個缺口終於被一個 升級了的大爆炸理論填補了。 它叫暴脹宇宙論。 它識別了一種特別的能量, 可以自然產生爆炸時的 快速空間膨脹。 那個能量基於一種叫做量子場的東西, 但對於我們而言唯一重要的細節就是 這種能量的效率高到 不可能一次性 將它全部用完, 而這意味著在暴脹理論中, 產生了我們的宇宙的大爆炸 很有可能不是一個一次性的事件。 反之,這個能量不僅僅造成了我們的大爆炸, 也會造成無數個其他的大爆炸, 每一個都會產生一個不同的宇宙, 而我們的宇宙只是一個巨大的星雲泡沫中的 一個泡泡。
And now, when we meld this with string theory, here's the picture we're led to. Each of these universes has extra dimensions. The extra dimensions take on a wide variety of different shapes. The different shapes yield different physical features. And we find ourselves in one universe instead of another simply because it's only in our universe that the physical features, like the amount of dark energy, are right for our form of life to take hold. And this is the compelling but highly controversial picture of the wider cosmos that cutting-edge observation and theory have now led us to seriously consider.
而現在,當我們將它和弦理論融合一起的時候, 我們被領到一個特定的畫面。 每一個宇宙都有額外的維度。 這些額外的維度有著很多不同的形狀。 不同的形狀產生不同的物理特性。 而我們發現我們存在於這一個宇宙而不在另外一個 僅僅因為這是唯一一個宇宙 有著可以讓我們這種生命形成的物理特性, 比如說暗能量的數量。 這是一個很有說服力但又非常有爭議的 宇宙的畫面, 而最先進的觀察和理論正在指引我們 嚴肅的去考慮它。
One big remaining question, of course, is, could we ever confirm the existence of other universes? Well let me describe one way that might one day happen. The inflationary theory already has strong observational support. Because the theory predicts that the Big Bang would have been so intense that as space rapidly expanded, tiny quantum jitters from the micro world would have been stretched out to the macro world, yielding a distinctive fingerprint, a pattern of slightly hotter spots and slightly colder spots, across space, which powerful telescopes have now observed. Going further, if there are other universes, the theory predicts that every so often those universes can collide. And if our universe got hit by another, that collision would generate an additional subtle pattern of temperature variations across space that we might one day be able to detect. And so exotic as this picture is, it may one day be grounded in observations, establishing the existence of other universes.
當然,一個剩下的很大的問題便是 我們是否能證明 其他宇宙的存在? 讓我描述一種 這有一天可能發生的方式。 暴脹理論 已經有了很強大的觀測結果支持。 因為這個理論預測了 大爆炸會強烈到 當空間快速的膨脹的時候, 在微型世界中細小的量子暴動 也會被拉扯到整個宏觀世界, 而產生一種特殊的印記 -- 一種在空間中有著稍微熱些的地方 和稍微冷些的地方的規律, 而強大的望遠鏡可以觀察到它。 更進一步,如果其他的宇宙的確存在, 那理論預測這些宇宙有些時候 會和對方相撞, 而如果我們的宇宙和另外一個相撞, 撞擊的能量 會在空間中產生一種額外的 細微的溫差規律, 而我們有一天可能可以 觀察到它。 而無論這個理論是如何的奇異, 有一天它有可能會被 觀察證實 其他宇宙的存在。
I'll conclude with a striking implication of all these ideas for the very far future. You see, we learned that our universe is not static, that space is expanding, that that expansion is speeding up and that there might be other universes all by carefully examining faint pinpoints of starlight coming to us from distant galaxies. But because the expansion is speeding up, in the very far future, those galaxies will rush away so far and so fast that we won't be able to see them -- not because of technological limitations, but because of the laws of physics. The light those galaxies emit, even traveling at the fastest speed, the speed of light, will not be able to overcome the ever-widening gulf between us. So astronomers in the far future looking out into deep space will see nothing but an endless stretch of static, inky, black stillness. And they will conclude that the universe is static and unchanging and populated by a single central oasis of matter that they inhabit -- a picture of the cosmos that we definitively know to be wrong.
讓我以由這些 想法產生的一個在遙遠的未來有著 驚人的後果 來結尾。 你看,我們學到了 我們的宇宙并不是靜止的, 空間正在擴張, 而擴張的速度也在加快, 還有其他的宇宙的確有可能存在。 這些都是由小心的調查 由遙遠的星系傳來的 微弱的星光。 但因為擴張的速度在加快, 在很遙遠的未來, 那些星系便會加速遠離到 我們再也無法看到它們 -- 不是因為技術上的限制, 而是因為物理定律。 那些星系發射的光線, 就算以最快的速度,光速來移動, 也不能比超越我們之間的 不停的在加大的距離。 所以當未來的天文學家 往太空深處查看的時候, 除了無盡的靜止的漆黑, 什麽也看不到。 而他們會認為 宇宙是靜止和不變的, 而其中只有一個他們居住的 中心的樂土 -- 一個我們確定的知道是錯誤的 宇宙觀。
Now maybe those future astronomers will have records handed down from an earlier era, like ours, attesting to an expanding cosmos teeming with galaxies. But would those future astronomers believe such ancient knowledge? Or would they believe in the black, static empty universe that their own state-of-the-art observations reveal? I suspect the latter. Which means that we are living through a remarkably privileged era when certain deep truths about the cosmos are still within reach of the human spirit of exploration. It appears that it may not always be that way. Because today's astronomers, by turning powerful telescopes to the sky, have captured a handful of starkly informative photons -- a kind of cosmic telegram billions of years in transit. and the message echoing across the ages is clear. Sometimes nature guards her secrets with the unbreakable grip of physical law. Sometimes the true nature of reality beckons from just beyond the horizon.
或許這些未來的天文學家會有從前一個紀元 留下的記錄, 像我們的一樣, 陳述著一個有無數的星雲點綴的 不停的擴張的宇宙。 但這些未來的天文學家們 會否相信這些古老的知識? 又或者他們會相信 他們自己的先進的觀察帶來的 那個漆黑,寧靜并空虛的宇宙? 我覺得會是後者。 這意味著我們正活在一個 有著特殊的榮幸的紀元, 當宇宙最深奧的真相 仍然存在在人類探索精神 能夠到達的地方。 但這並不永遠如此。 因為當今天的天文學家 用強大的望遠鏡對準夜空時, 他們發現了一些分明的帶著信息的光子 -- 一種經歷了上億年的 宇宙電報。 而從亙古傳來的信息很清楚。 有些時候自然用不可違背的 物理定律來 守護她的秘密。 有些時候現實真正的面貌就在 地平線的遠端。
Thank you very much.
謝謝。
(Applause)
(掌聲)
Chris Anderson: Brian, thank you. The range of ideas you've just spoken about are dizzying, exhilarating, incredible. How do you think of where cosmology is now, in a sort of historical side? Are we in the middle of something unusual historically in your opinion?
Chris Anderson: Brian,謝謝。 你剛剛所講的思想範圍 使人有些頭暈但興奮。 你覺得 現在的天文學 在歷史中佔有什麽樣的位置? 在你的意見來說,我們是否正在經歷著一個特別的歷史片段?
BG: Well it's hard to say. When we learn that astronomers of the far future may not have enough information to figure things out, the natural question is, maybe we're already in that position and certain deep, critical features of the universe already have escaped our ability to understand because of how cosmology evolves. So from that perspective, maybe we will always be asking questions and never be able to fully answer them.
BG:這有些難說。 當我們瞭解到未來的天文學家 有可能沒有足夠的信息來瞭解一切, 一個自然的問題便是,我們有可能已經在這樣的一個位置, 而一些深奧的,重要的宇宙特性 已經逃出了我們可以理解的範圍, 僅僅因為天文學的發展。 所以從這個觀點來看, 可能我們已經處於無法回答 我們問的問題的局面。
On the other hand, we now can understand how old the universe is. We can understand how to understand the data from the microwave background radiation that was set down 13.72 billion years ago -- and yet, we can do calculations today to predict how it will look and it matches. Holy cow! That's just amazing. So on the one hand, it's just incredible where we've gotten, but who knows what sort of blocks we may find in the future.
但換個角度來說,我們現在可以理解 宇宙到底有多老。 我們可以理解 十四億年前留下的宇宙微波背景輻射 所傳達的信息 -- 甚至於,今天我們可以計算以及預測它的樣貌 并與觀察符合。 天啊!這太棒了。 所以換個角度來說的話,我們到達今天已經很不可思議, 但誰知道我們將來會遇到什麽樣的障礙。
CA: You're going to be around for the next few days. Maybe some of these conversations can continue. Thank you. Thank you, Brian. (BG: My pleasure.)
CA:你會停留幾天。 或許可以繼續討論這些話題。 謝謝你。謝謝你,Brian。(BG:我的榮幸。)
(Applause)
(掌聲)