There is something about physics that has been really bothering me since I was a little kid. And it's related to a question that scientists have been asking for almost 100 years, with no answer. How do the smallest things in nature, the particles of the quantum world, match up with the largest things in nature -- planets and stars and galaxies held together by gravity?
物理學中有件事情 自幼時就一直非常困擾我。 近百年來科學家思索著這個問題 但沒有答案。 自然界中最小的東西, 即量子世界的微粒子,如何與 自然界中最大的東西,即星系裡 以重力連結的行星和恆星相對應呢?
As a kid, I would puzzle over questions just like this. I would fiddle around with microscopes and electromagnets, and I would read about the forces of the small and about quantum mechanics and I would marvel at how well that description matched up to our observation. Then I would look at the stars, and I would read about how well we understand gravity, and I would think surely, there must be some elegant way that these two systems match up. But there's not. And the books would say, yeah, we understand a lot about these two realms separately, but when we try to link them mathematically, everything breaks.
童年的我,為這樣的問題搜索枯腸。 我操作顯微鏡和電磁鐵, 我研讀微物質的力學 和量子力學, 讚嘆其描述和我們的觀察 是如此的相應。 我也觀看星星, 閱讀我們所知的重力, 想當然耳,大和小的兩個系統 必然有種精美而優雅的相應方式。 但可惜卻沒有。 根據書本, 我們很懂這兩個各別的系統, 但是一旦嘗試以數學模式來連結, 就完全行不通了。
And for 100 years, none of our ideas as to how to solve this basically physics disaster, has ever been supported by evidence. And to little old me -- little, curious, skeptical James -- this was a supremely unsatisfying answer.
百年來, 我們對於如何解決 這基本的物理問題一籌莫展, 沒有可以支持的證據。 對於小老弟在下── 小小、好奇、不信服的詹姆斯── 這是絕對不可接受的。
So, I'm still a skeptical little kid. Flash-forward now to December of 2015, when I found myself smack in the middle of the physics world being flipped on its head. It all started when we at CERN saw something intriguing in our data: a hint of a new particle, an inkling of a possibly extraordinary answer to this question.
今天的我,仍是個不易信服的小孩。 時間快轉到 2015 年十二月, 我重拍額頭, 突然有個物理世界裡的靈光一閃。 始自我們在歐洲核子研究組織 CERN 看到有趣的數據: 它們隱射一種新的粒子, 暗示一個可能不同凡響的解答。
So I'm still a skeptical little kid, I think, but I'm also now a particle hunter. I am a physicist at CERN's Large Hadron Collider, the largest science experiment ever mounted. It's a 27-kilometer tunnel on the border of France and Switzerland buried 100 meters underground. And in this tunnel, we use superconducting magnets colder than outer space to accelerate protons to almost the speed of light and slam them into each other millions of times per second, collecting the debris of these collisions to search for new, undiscovered fundamental particles. Its design and construction took decades of work by thousands of physicists from around the globe, and in the summer of 2015, we had been working tirelessly to switch on the LHC at the highest energy that humans have ever used in a collider experiment.
我仍是個不信服的小子, 現在也是個找尋粒子的人。 我是 CERN 的物理學家, 用「大型強子對撞機(LHC)」, 一具到目前為止所安裝過的 最大型的科學實驗儀器。 這是條在法國和瑞士邊界間的 二十七公里長的隧道, 埋在一百公尺深的地下。 隧道裡, 我們用比外太空更低溫的超導磁體 把質子加速到接近光速, 使它們每秒彼此互相撞擊數百萬次, 收集碰撞的碎片, 搜索新的、尚未被發現的基本粒子。 其設計和施工費時幾十年, 全球各地數以千計的 物理學家通力合作, 在 2015 年夏天, 我們不眠不休地讓 LHC 開始運轉, 實驗用到人類前所未有的 最高撞擊能量。
Now, higher energy is important because for particles, there is an equivalence between energy and particle mass, and mass is just a number put there by nature. To discover new particles, we need to reach these bigger numbers. And to do that, we have to build a bigger, higher energy collider, and the biggest, highest energy collider in the world is the Large Hadron Collider. And then, we collide protons quadrillions of times, and we collect this data very slowly, over months and months. And then new particles might show up in our data as bumps -- slight deviations from what you expect, little clusters of data points that make a smooth line not so smooth. For example, this bump, after months of data-taking in 2012, led to the discovery of the Higgs particle -- the Higgs boson -- and to a Nobel Prize for the confirmation of its existence.
高能量至關重要,對粒子而言, 能量和質量轉換守恆, 質量只是個自然界擺在那兒的數字。 為要發現新的粒子, 我們必須耗費更多的能量。 因此,我們必須建造更大、 更耗能的對撞機; 而世界上最大的對撞機 是 LHC。 然後,我們碰撞質子 千萬億(10 的 24 次方)次 我們經年累月慢慢地收集資料。 或許新的粒子會以突起的形狀 呈現在資料的平滑線外── 稍微偏離預期值, 小小群集的數據點, 使得平滑的線不再那麼地平滑。 例如,這個凸起, 2012 年累月的數據採集後, 導致發現了「希格斯粒子」, 或稱「希格斯玻色子」, 和因證明它存在而獲得的諾貝爾奬。
This jump up in energy in 2015 represented the best chance that we as a species had ever had of discovering new particles -- new answers to these long-standing questions, because it was almost twice as much energy as we used when we discovered the Higgs boson. Many of my colleagues had been working their entire careers for this moment, and frankly, to little curious me, this was the moment I'd been waiting for my entire life. So 2015 was go time.
2015 年看到的能量凸起 代表人類發現新粒子的絕佳機會, 這些長期謎題的新解答, 因它所耗的能量幾乎是 發現希格斯玻色子時耗能的兩倍。 我的許多同事 整個職涯都在追尋此刻, 坦率地說,對好奇的我而言, 這是我一輩子等待的時刻。 2015 年是跳下去做, 不回頭的時刻。
So June 2015, the LHC is switched back on. My colleagues and I held our breath and bit our fingernails, and then finally we saw the first proton collisions at this highest energy ever. Applause, champagne, celebration. This was a milestone for science, and we had no idea what we would find in this brand-new data. And then a few weeks later, we found a bump. It wasn't a very big bump, but it was big enough to make you raise your eyebrow. But on a scale of one to 10 for eyebrow raises, if 10 indicates that you've discovered a new particle, this eyebrow raise is about a four.
因此於 2015 年六月, LHC 又運轉了。 同事和我屏息、緊張又興奮, 終於看到質子以有史以來 最高的能量互撞。 鼓掌,開香檳,慶祝。 這是科學的里程碑, 我們不知道會在 這全新的數據裡找到什麼。 數週後,我們發現了凸起的數據。 凸起雖不算大, 但已足以讓人訝異。 從 1 到 10 的訝異程度, 10 代表你已發現了新的粒子, 這是個程度大約 4 的訝異。
(Laughter)
(笑聲)
I spent hours, days, weeks in secret meetings, arguing with my colleagues over this little bump, poking and prodding it with our most ruthless experimental sticks to see if it would withstand scrutiny. But even after months of working feverishly -- sleeping in our offices and not going home, candy bars for dinner, coffee by the bucketful -- physicists are machines for turning coffee into diagrams --
我花了無數的時間秘密開會, 和同事辯論這個小凸起, 努力在雞蛋裡挑骨頭, 看它是否經得起最嚴厲的檢視。 即使在數月不眠不休地工作後── 不回家,而是睡在辦公室, 以糖果零嘴當晚餐, 大桶大桶地喝咖啡── 物理學家就是 把咖啡變成圖表的機器──
(Laughter)
(笑聲)
This little bump would not go away. So after a few months, we presented our little bump to the world with a very clear message: this little bump is interesting but it's not definitive, so let's keep an eye on it as we take more data. So we were trying to be extremely cool about it.
這個小凸起並未消失。 幾個月後, 我們向世界展示了這個小凸起 和一個非常明確的信息: 這個小凸起有趣,但是不明確, 讓我們收集更多的數據 並持續關注它。 我們試圖非常冷靜地看待它。
And the world ran with it anyway. The news loved it. People said it reminded them of the little bump that was shown on the way toward the Higgs boson discovery. Better than that, my theorist colleagues -- I love my theorist colleagues -- my theorist colleagues wrote 500 papers about this little bump.
儘管如此,世界隨它起舞。 新聞界喜愛它。 人們說它讓他們想起發現 希格斯玻色子路上的那個小凸起。 更棒的是,我的理論派同事們── 我喜歡我的理論派同事們── 我的理論派同事們寫了五百篇 關於這個小凸起的文章。
(Laughter)
(笑聲)
The world of particle physics had been flipped on its head. But what was it about this particular bump that caused thousands of physicists to collectively lose their cool? This little bump was unique. This little bump indicated that we were seeing an unexpectedly large number of collisions whose debris consisted of only two photons, two particles of light. And that's rare.
粒子物理學的世界已然翻轉。 這個小凸起的什麼特點 使得成千上萬的物理學家 熱血沸騰呢? 這個小凸起獨一無二。 這個小凸起顯示 我們看到了意料之外的大量碰撞, 碰撞後只殘留兩個光子, 兩個光粒子。 這相當罕見。
Particle collisions are not like automobile collisions. They have different rules. When two particles collide at almost the speed of light, the quantum world takes over. And in the quantum world, these two particles can briefly create a new particle that lives for a tiny fraction of a second before splitting into other particles that hit our detector. Imagine a car collision where the two cars vanish upon impact, a bicycle appears in their place --
粒子碰撞不像汽車碰撞。 碰撞的規則不同。 當兩個粒子以接近光速的速度互撞, 行為就由量子世界的規則所掌控。 在量子世界中, 這兩個粒子能短暫地 創造一個新粒子, 只瞬間存在, 頃刻後分裂成其他粒子, 並擊中我們的偵測器。 想像一下兩輛汽車互撞, 汽車在相撞的當下消失, 原地出現了一輛自行車──
(Laughter)
(笑聲)
And then that bicycle explodes into two skateboards, which hit our detector.
那輛自行車緊接著爆炸, 變成兩個滑板, 撞到我們的偵測器。
(Laughter)
(笑聲)
Hopefully, not literally. They're very expensive.
當然不是字面上的撞上, 偵測器可是很貴的啊。
Events where only two photons hit out detector are very rare. And because of the special quantum properties of photons, there's a very small number of possible new particles -- these mythical bicycles -- that can give birth to only two photons. But one of these options is huge, and it has to do with that long-standing question that bothered me as a tiny little kid, about gravity.
僅僅兩個光子撞擊偵測器的 事件非常地罕見。 由於光子具有量子的特性, 新粒子,也就是這些虛搆的自行車, 出現的機率相當罕見, 只產生兩個光子的新粒子非常罕見。 但是有一選項極可能發生, 和一個長期存在的未解題有關, 就是那個自幼就困擾我的重力問題。
Gravity may seem super strong to you, but it's actually crazily weak compared to the other forces of nature. I can briefly beat gravity when I jump, but I can't pick a proton out of my hand. The strength of gravity compared to the other forces of nature? It's 10 to the minus 39. That's a decimal with 39 zeros after it.
或許你認為重力強而有力, 但是相較於自然界的其他力量, 它其實超弱的。 當我跳起時,能夠短暫地擺脫重力, 但我卻無法用手撿起一粒質子。 相較於自然界的其他力量, 重力的強度如何呢? 是 10 的負 39 次方。 小數點之後跟著 39 個零。
Worse than that, all of the other known forces of nature are perfectly described by this thing we call the Standard Model, which is our current best description of nature at its smallest scales, and quite frankly, one of the most successful achievements of humankind -- except for gravity, which is absent from the Standard Model. It's crazy. It's almost as though most of gravity has gone missing. We feel a little bit of it, but where's the rest of it? No one knows.
更糟的是, 所有其他已知的自然界力量都可被 所謂的「標準模型」完美地描述。 那是我們目前描述自然界 最小尺度的最佳模型。 坦白說, 那是人類最大的成就之一, 重力標準模型不存在是唯一的例外。 難以置信。 彷彿大部分的重力消失不見了。 我們察覺到少許重力, 但其他的部分呢? 沒有人知道。
But one theoretical explanation proposes a wild solution. You and I -- even you in the back -- we live in three dimensions of space. I hope that's a non-controversial statement.
但有個理論提供了瘋狂的解釋。 你們和我── 包括坐在後面的諸位── 我們生活在三度空間裡。 希望這並無爭議。
(Laughter)
(笑聲)
All of the known particles also live in three dimensions of space. In fact, a particle is just another name for an excitation in a three-dimensional field; a localized wobbling in space. More importantly, all the math that we use to describe all this stuff assumes that there are only three dimensions of space. But math is math, and we can play around with our math however we want. And people have been playing around with extra dimensions of space for a very long time, but it's always been an abstract mathematical concept. I mean, just look around you -- you at the back, look around -- there's clearly only three dimensions of space.
所有已知的粒子也存在三度空間裡。 事實上,粒子只是別名, 是三度空間裡的激發; 空間中的局部擺動。 更重要的是,我們用來描述 所有這些玩意的數學 全都假設只有三度空間。 但數學就是數學, 我們可以隨意擺弄數學。 長久以來,人們一直悠遊於 更多維度的數學中, 但僅僅是個抽象的數學概念而已。 我的意思是,看看你們的周圍── 坐在後面的諸位,請環顧四周── 顯然只有三度空間。
But what if that's not true? What if the missing gravity is leaking into an extra-spatial dimension that's invisible to you and I? What if gravity is just as strong as the other forces if you were to view it in this extra-spatial dimension, and what you and I experience is a tiny slice of gravity make it seem very weak? If this were true, we would have to expand our Standard Model of particles to include an extra particle, a hyperdimensional particle of gravity, a special graviton that lives in extra-spatial dimensions.
但,倘若事實並非如此呢? 如果消失的重力 流入了我們看不見的第四度空間呢? 如果重力和其他的力量同樣有力, 前提是增加維度來看待它; 如果你我目前體驗到的重力 只是一小部分, 所以才會看起來這麼弱呢? 假如這是真的, 我們就必須擴大粒子的標準模型, 包括其他的粒子, 「超維度的重力子」, 存在另一度空間的重力子。
I see the looks on your faces. You should be asking me the question, "How in the world are we going to test this crazy, science fiction idea, stuck as we are in three dimensions?" The way we always do, by slamming together two protons --
我注意到你們的臉上的表情。 你們該問我: 「要怎樣去測試 這瘋狂而科幻的想法呢? 我們到底身處在三度空間裡啊!」 老法子, 使兩個光子互撞──
(Laughter)
(笑聲)
Hard enough that the collision reverberates into any extra-spatial dimensions that might be there, momentarily creating this hyperdimensional graviton that then snaps back into the three dimensions of the LHC and spits off two photons, two particles of light. And this hypothetical, extra-dimensional graviton is one of the only possible, hypothetical new particles that has the special quantum properties that could give birth to our little, two-photon bump.
碰撞反射到或許存在的 多度空間已經夠難了, 遑論頃刻間造出超維度的重力子, 並且撞擊到三度空間的 LHC, 又再分裂為兩個光子, 兩個光粒子。 這假設的超維度重力子, 唯一可能假設的新粒子, 具有特別的量子空間特性, 能產生我們這個小小的二光子凸起。
So, the possibility of explaining the mysteries of gravity and of discovering extra dimensions of space -- perhaps now you get a sense as to why thousands of physics geeks collectively lost their cool over our little, two-photon bump. A discovery of this type would rewrite the textbooks. But remember, the message from us experimentalists that actually were doing this work at the time, was very clear: we need more data. With more data, the little bump will either turn into a nice, crisp Nobel Prize --
因此,解釋重力的奧秘, 和發現另一度空間的可能性── 現在或許你們稍稍明白了 為何成千上萬的怪胎物理學家 會因小小的兩光子凸起而集體激動。 這樣的發現將會改寫教科書。 但請記住, 我們這些當時真正做實驗的人 傳達的訊息非常的清楚: 我們需要更多的數據。 有了更多的數據, 這小小的凸起可能會成為 漂亮、清新的諾貝爾獎──
(Laughter)
(笑聲)
Or the extra data will fill in the space around the bump and turn it into a nice, smooth line.
或者增加的數據 會填滿凸起周邊的空間, 使它成為平滑、順暢的線條。
So we took more data, and with five times the data, several months later, our little bump turned into a smooth line. The news reported on a "huge disappointment," on "faded hopes," and on particle physicists "being sad." Given the tone of the coverage, you'd think that we had decided to shut down the LHC and go home.
因此我們收取更多的數據, 又經過幾個月,增加了五倍的數據, 我們的小凸起 成為平滑的線條。 新聞報導了「大失望」、 「消逝的希望」, 以及粒子物理學家們很「悲傷」。 根據報導的語氣, 你們會認為我們已經決定 關掉 LHC,打道回府了。
(Laughter)
(笑聲)
But that's not what we did. But why not? I mean, if I didn't discover a particle -- and I didn't -- if I didn't discover a particle, why am I here talking to you? Why didn't I just hang my head in shame and go home?
但我們沒那樣做。 為什麼不呢? 如果我沒發現新粒子── 而我的確沒發現── 如果我沒發現新粒子, 怎麼還在這裡對你們演講? 我怎麼沒羞恥地低著頭, 躲回家裡去呢?
Particle physicists are explorers. And very much of what we do is cartography. Let me put it this way: forget about the LHC for a second. Imagine you are a space explorer arriving at a distant planet, searching for aliens. What is your first task? To immediately orbit the planet, land, take a quick look around for any big, obvious signs of life, and report back to home base. That's the stage we're at now. We took a first look at the LHC for any new, big, obvious-to-spot particles, and we can report that there are none. We saw a weird-looking alien bump on a distant mountain, but once we got closer, we saw it was a rock.
粒子物理學家是探索者。 我們繪製很多的圖。 暫時先不管 LHC,讓我這樣來描述: 想像你是個太空探險家, 飛到一個遙遠的行星去搜索外星人。 你的第一個任務是什麼? 是立刻環繞行星、掃視地面, 快速地巡視四周, 看有沒有大的、顯著的生命跡象, 並回報基地。 這正是我們眼前的階段。 我們先快巡 LHC, 看有沒有大的、顯著的粒子, 我們回報沒有。 如同我們看到遠處 有個像是外星人的怪異凸起, 一旦近看,發現只是個石頭。
But then what do we do? Do we just give up and fly away? Absolutely not; we would be terrible scientists if we did. No, we spend the next couple of decades exploring, mapping out the territory, sifting through the sand with a fine instrument, peeking under every stone, drilling under the surface. New particles can either show up immediately as big, obvious-to-spot bumps, or they can only reveal themselves after years of data taking.
接下來呢?我們放棄、飛離嗎? 絕不; 若那樣做,我們就是差勁的科學家。 不,我們用接下來的幾十年去探索, 繪製地圖, 用精密儀器仔細地篩過沙土, 翻遍每塊石頭, 往地表下鑽。 新粒子可能以 大而顯著的型態立即顯現, 或在收集許多數據後才會顯露出來。
Humanity has just begun its exploration at the LHC at this big high energy, and we have much searching to do. But what if, even after 10 or 20 years, we still find no new particles? We build a bigger machine.
人類才剛開始以如此高的能量 在 LHC 上探索, 我們要找的可多著呢。 如果十或二十年後, 我們仍然沒發現新的粒子呢? 我們就建造更大的機器。
(Laughter)
(笑聲)
We search at higher energies. We search at higher energies. Planning is already underway for a 100-kilometer tunnel that will collide particles at 10 times the energy of the LHC. We don't decide where nature places new particles. We only decide to keep exploring. But what if, even after a 100-kilometer tunnel or a 500-kilometer tunnel or a 10,000-kilometer collider floating in space between the Earth and the Moon, we still find no new particles? Then perhaps we're doing particle physics wrong.
我們用更高的能量去尋找。 我們用更高的能量尋找。 我們已在規畫一百公里長的隧道, 它的撞擊力道是 LHC 的十倍。 大自然在何處擺放新粒子 不歸我們作主。 我們只能決定繼續探索。 倘若用了一百公里的加速隧道, 五百公里的隧道, 或是一萬公里長, 漂浮在地球和月亮間 太空中的隧道, 仍然找不到新粒子呢? 也許我們粒子物理的理論是錯的。
(Laughter)
(笑聲)
Perhaps we need to rethink things. Maybe we need more resources, technology, expertise than what we currently have. We already use artificial intelligence and machine learning techniques in parts of the LHC, but imagine designing a particle physics experiment using such sophisticated algorithms that it could teach itself to discover a hyperdimensional graviton.
也許我們需要重新思考。 也許我們需要比現有 更多的資源、技術和專業知識。 我們已經將人工智能和機器學習技術 用在部分的 LHC 中, 想像把這種複雜的演算法 設計在粒子物理實驗裡, 教會它自己去發現超維重力子。
But what if? What if the ultimate question: What if even artificial intelligence can't help us answer our questions? What if these open questions, for centuries, are destined to be unanswered for the foreseeable future? What if the stuff that's bothered me since I was a little kid is destined to be unanswered in my lifetime? Then that ... will be even more fascinating.
如果, 如果最終的問題: 如果連人工智慧也不能 幫助我們回答問題呢? 如果這些數百年無解的問題, 注定在可預見的未來仍然無解呢? 如果那自幼就困擾我的問題 注定在我的有生之年無解呢? 那…… 就會更加地迷人了。
We will be forced to think in completely new ways. We'll have to go back to our assumptions, and determine if there was a flaw somewhere. And we'll need to encourage more people to join us in studying science since we need fresh eyes on these century-old problems. I don't have the answers, and I'm still searching for them. But someone -- maybe she's in school right now, maybe she's not even born yet -- could eventually guide us to see physics in a completely new way, and to point out that perhaps we're just asking the wrong questions. Which would not be the end of physics, but a novel beginning.
我們將被迫以全新的方式思考。 我們必須回到原先的假設, 確定是否某個環節有著缺陷。 我們需要鼓勵更多人 加入我們學習科學, 因為我們需要清新的眼睛 研究這些百年的老問題。 我仍在尋找,沒有答案。 但某人──也許正在就學, 也許尚未出生── 最終能引導我們 以全新的方式去看待物理學, 指出來,我們可能只是問錯了問題。 這不會終結物理學, 而會是個嶄新的開始。
Thank you.
謝謝。
(Applause)
(鼓掌)