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  • So last year, on the Fourth of July,

    去年7月4號

  • experiments at the Large Hadron Collider

    在大型強子對撞機(LHC)的實驗裡

  • discovered the Higgs boson.

    希格斯玻色子被發現了

  • It was a historical day.

    那是歷史性的一刻

  • There's no doubt that from now on,

    無庸置疑地,從現在開始

  • the Fourth of July will be remembered

    7月4號不再被認為是 美國獨立紀念日

  • not as the day of the Declaration of Independence,

    而是發現希格斯玻色子的重要日子

  • but as the day of the discovery of the Higgs boson.

    至少對歐洲核子研究組織是這樣的

  • Well, at least, here at CERN.

    但是對我而言,那天最大的驚喜

  • But for me, the biggest surprise of that day

    就是沒有太大的驚喜

  • was that there was no big surprise.

    在物理理論學家的眼中

  • In the eye of a theoretical physicist,

    希格斯玻子是一個很絕妙的解釋

  • the Higgs boson is a clever explanation

    它解釋了一些基本粒子如何獲得質量

  • of how some elementary particles gain mass,

    但是這看來就是個不盡滿意

  • but it seems a fairly unsatisfactory

    而且不夠完整的解答

  • and incomplete solution.

    太多問題都無法回答

  • Too many questions are left unanswered.

    希格斯玻色子不夠美麗

  • The Higgs boson does not share the beauty,

    不夠均稱,不夠優雅

  • the symmetry, the elegance,

    不足以和基本粒子世界相比

  • of the rest of the elementary particle world.

    因此,大多數理論學家

  • For this reason, the majority of theoretical physicists

    不相信希格斯玻色子就是所有的真相

  • believe that the Higgs boson could not

    我們希望新的粒子和新的現象

  • be the full story.

    能隨著希格斯玻色子出現

  • We were expecting new particles and new phenomena

    但目前從LHC對撞機得來的測量 卻沒有顯示什麼新的粒子和新的現象

  • accompanying the Higgs boson.

    當然,目前的論斷並不是絕對的

  • Instead, so far, the measurements

    2015年,LHC對撞機將會加倍

  • coming from the LHC show no signs of new particles

    質子撞擊的能量

  • or unexpected phenomena.

    這些更強烈的撞擊

  • Of course, the verdict is not definitive.

    能讓我們進一步了探索粒子世界

  • In 2015, the LHC will almost double

    我們一定能從中知道更多

  • the energy of the colliding protons,

    但當下我們還沒找到新現象的證據

  • and these more powerful collisions

    讓我們假設我們今天知道的粒子

  • will allow us to explore further the particle world,

    包含希格斯玻色子

  • and we will certainly learn much more.

    是自然界中僅有的基本粒子

  • But for the moment, since we have found

    即使它們能爆發的能量 比我們今天所知的多上更多

  • no evidence for new phenomena, let us suppose

    我們來看看這個假設會帶來什麼事

  • that the particles that we know today,

    我們會發現宇宙驚奇又迷人的結果

  • including the Higgs boson,

    在我繼續解釋之前

  • are the only elementary particles in nature,

    先讓我說明希格斯玻色子是什麼

  • even at energies much larger

    要說明的話,我們必須回到

  • than what we have explored so far.

    宇宙大爆炸之後的百億分之一秒

  • Let's see where this hypothesis is going to lead us.

    根據希格斯理論

  • We will find a surprising and intriguing result

    在那瞬間 一件非常戲劇化的事件在宇宙中發生

  • about our universe, and to explain my point,

    時空經歷轉變期

  • let me first tell you what the Higgs is about,

    這個轉變期 和水在零度以下結冰的過程非常像

  • and to do so, we have to go back

    但這個例子裡

  • to one tenth of a billionth of a second

    轉變期不是分子在物質裡的重新排列

  • after the Big Bang.

    而是時空結構的改變

  • And according to the Higgs theory,

    在這段轉變期,空間充滿物質

  • at that instant, a dramatic event took place

    就是我們說的希格斯場

  • in the universe.

    這種物質我們可能看不見

  • Space-time underwent a phase transition.

    但卻擁有物理性質

  • It was something very similar to the phase transition

    它隨時環繞我們

  • that occurs when water turns into ice

    就像我們在這房間內呼吸的空氣一樣

  • below zero degrees.

    有些基本粒子和這種物質互動 從過程中獲得能量

  • But in our case, the phase transition

    這種內在的能量 就是我們今天說的粒子質量

  • is not a change in the way the molecules

    而藉由發現希格斯玻色子

  • are arranged inside the material,

    LHC對撞機證實這種物質是真的

  • but is about a change

    因為希格斯玻色子正由這種物質組成

  • of the very fabric of space-time.

    簡單來說,這就是希格斯故事的梗概

  • During this phase transition, empty space

    但更有趣的在後頭

  • became filled with a substance

    研究希格斯理論的同時

  • that we now call Higgs field.

    理論學家發現

  • And this substance may seem invisible to us,

    並非經由實驗,而只是數學演算

  • but it has a physical reality.

    他們發現希格斯場並不是 只以我們今日發現的形式存在

  • It surrounds us all the time,

    就像物質可以有液態和固態兩種狀態

  • just like the air we breathe in this room.

    所以希格斯場 也就是那填滿時空的物質

  • And some elementary particles interact

    可以存在於兩種狀態下

  • with this substance, gaining energy in the process.

    除了已知的希格斯場之外

  • And this intrinsic energy is what we call

    希格斯場還可能比現在 所知的高出幾十億密度存在

  • the mass of a particle,

    光是另一種希格斯場的可能存在

  • and by discovering the Higgs boson, the LHC

    就帶來了潛在的問題

  • has conclusively proved that this substance is real,

    因為根據量子力學定律

  • because it is the stuff the Higgs bosons are made of.

    兩種狀態之間的轉變是有可能的

  • And this, in a nutshell, is the essence of the Higgs story.

    即使兩個狀態之間有能量差間隔

  • But this story is far more interesting than that.

    詞如其名,這個現象被稱為量子穿隧

  • By studying the Higgs theory,

    因為量子穿隧效應

  • theoretical physicists discovered,

    我可以從這間房間消失

  • not through an experiment

    再從另外一個房間出現

  • but with the power of mathematics,

    簡單來說就是穿越牆壁

  • that the Higgs field does not necessarily exist

    但別期待我會真的在你們面前表演

  • only in the form that we observe today.

    因為讓我能穿越牆壁的機率十分渺小

  • Just like matter can exist as liquid or solid,

    在這發生之前你們得等上好一陣子

  • so the Higgs field, the substance that fills all space-time,

    但相信我 量子穿隧是一個真實存在的現象

  • could exist in two states.

    且已經被很多機制發現

  • Besides the known Higgs state,

    例如,穿隧兩極真空管 一個在電子學中常用的組件

  • there could be a second state in which the Higgs field

    因為量子穿隧效應而被製造出來

  • is billions and billions times denser

    但讓我們再回到希格斯場

  • than what we observe today,

    如果超濃度的希格斯場存在

  • and the mere existence of another state

    那,因為量子穿隧效應

  • of the Higgs field poses a potential problem.

    在這狀態下的泡泡 可以突然出現在宇宙中的特定時空

  • This is because, according to the laws

    就和我們煮滾水的時候一樣

  • of quantum mechanics, it is possible

    蒸氣泡泡從水中蒸發

  • to have transitions between two states,

    然後膨脹,從液態變成氣態

  • even in the presence of an energy barrier

    同理,一顆泡泡在超濃度的希格斯場

  • separating the two states,

    可以因為量子穿隧效應而出現

  • and the phenomenon is called,

    泡泡會以光速膨脹,佔領空間

  • quite appropriately, quantum tunneling.

    將希格斯場從熟悉帶到全新的狀態

  • Because of quantum tunneling,

    這是個問題嗎?

  • I could disappear from this room

    是,很大的問題

  • and reappear in the next room,

    在日常生活中可能難以理解

  • practically penetrating the wall.

    但希格斯場的密度 對於物質構造非常重要

  • But don't expect me to actually perform the trick

    如果希格斯場密度只是比一般高一點

  • in front of your eyes, because the probability

    我們就會看到原子核中原子收縮

  • for me to penetrate the wall is ridiculously small.

    中子衰變,核子解體

  • You would have to wait a really long time

    氫會變成宇宙中 唯一可能存在的化學元素

  • before it happens, but believe me,

    而超濃度的希格斯場

  • quantum tunneling is a real phenomenon,

    並不是只比今天的希格斯場 密度高上幾倍

  • and it has been observed in many systems.

    而是幾十億倍

  • For instance, the tunnel diode,

    如果時空被這個希格斯場填滿

  • a component used in electronics,

    所有原子物質都會崩解

  • works thanks to the wonders

    沒有任何分子結構能夠存在 沒有生命

  • of quantum tunneling.

    所以我想

  • But let's go back to the Higgs field.

    未來希格斯場有可能會經歷轉變期

  • If the ultra-dense Higgs state existed,

    和量子穿隧效應

  • then, because of quantum tunneling,

    進入這個恐怖,高濃度的狀態嗎?

  • a bubble of this state could suddenly appear

    換句話說,我問自己

  • in a certain place of the universe at a certain time,

    希格斯場在宇宙中的命運是什麼?

  • and it is analogous to what happens when you boil water.

    而回答這個問題的關鍵 在於希格斯玻色子的質量

  • Bubbles of vapor form inside the water,

    在一次LHC的實驗裡發現

  • then they expand, turning liquid into gas.

    希格斯玻色子的質量 是1260億電子伏特

  • In the same way, a bubble of the ultra-dense Higgs state

    用我們熟悉的單位表示的話其實不多

  • could come into existence because of quantum tunneling.

    差不多是10的負22次方公克

  • The bubble would then expand at the speed of light,

    但是對粒子單位來說很大

  • invading all space, and turning the Higgs field

    它就等於是整個DNA分子的重量

  • from the familiar state into a new state.

    有了從LHC得到的資料

  • Is this a problem? Yes, it's a big a problem.

    再加上從歐洲核子研究組織得到的

  • We may not realize it in ordinary life,

    我們試著計算

  • but the intensity of the Higgs field is critical

    宇宙經過量子穿隧 進入高濃度希格斯場的可能性

  • for the structure of matter.

    結果非常有趣

  • If the Higgs field were only a few times more intense,

    我們的計算顯示

  • we would see atoms shrinking, neutrons decaying

    希格斯玻色子的質量非常特別

  • inside atomic nuclei, nuclei disintegrating,

    它的質量剛剛好

  • and hydrogen would be

    可以讓宇宙處在一個不安定的狀態

  • the only possible chemical element in the universe.

    希格斯場的結構至今為止 仍處於搖擺不定的狀態

  • And the Higgs field, in the ultra-dense Higgs state,

    但最終還是會崩塌

  • is not just a few times more intense than today,

    根據我們的計算

  • but billions of times,

    我們就像露營的人

  • and if space-time were filled by this Higgs state,

    不小心將帳篷搭在懸崖邊

  • all atomic matter would collapse.

    最後,希格斯場會經歷轉變期

  • No molecular structures would be possible, no life.

    然後所有的物質會自我毀滅

  • So, I wonder, is it possible

    所以人類文明就是這樣消失的嗎?

  • that in the future, the Higgs field

    我不這樣覺得

  • will undergo a phase transition and,

    我們的計算顯示

  • through quantum tunneling, will be transformed

    希格斯場的量子穿隧

  • into this nasty, ultra-dense state?

    在接下來的10年到100年 不太可能會發生

  • In other words, I ask myself, what is the fate

    這是一段很長的時間

  • of the Higgs field in our universe?

    甚至比義大利成立穩定的政府還要長

  • And the crucial ingredient necessary

    即使發生了,我們也已經不在了

  • to answer this question is the Higgs boson mass.

    在約50億年後

  • And experiments at the LHC found that the mass

    太陽會變成紅巨星

  • of the Higgs boson is about 126 GeV.

    和地球繞日的軌跡一樣大

  • This is tiny when expressed in familiar units,

    地球會毀掉

  • because it's equal to something like

    1兆年之後

  • 10 to the minus 22 grams,

    如果黑暗能量還在供給

  • but it is large in particle physics units,

    太空依現在的速度膨脹

  • because it is equal to the weight

    你連到腳趾頭這麼短的距離都看不到

  • of an entire molecule

    因為你身邊的事物

  • of a DNA constituent.

    都在以比光速還要快的速度膨脹

  • So armed with this information from the LHC,

    所以要我們看到希格斯場膨脹 真的不怎麼可能

  • together with some colleagues here at CERN,

    我對希格斯場轉換感興趣的原因是

  • we computed the probability

    因為我想問:

  • that our universe could quantum tunnel

    為何希格斯玻色子的質量如此特別?

  • into the ultra-dense Higgs state,

    為何它剛剛好讓宇宙

  • and we found a very intriguing result.

    處於轉變的邊緣?

  • Our calculations showed

    理論學家永遠喜歡問"為什麼"

  • that the measured value of the Higgs boson mass

    不只是想要知道現象的成因

  • is very special.

    理論學家更感興趣的是

  • It has just the right value

    為何一個現象會以現在這個方式運作

  • to keep the universe hanging

    我們覺得這些"為什麼"可以給我們線索

  • in an unstable situation.

    找尋自然的基本定律

  • The Higgs field is in a wobbly configuration

    而能解答我問題的可能答案

  • that has lasted so far

    開啟了整個宇宙 真的是字面上的開啟

  • but that will eventually collapse.

    一直有人懷疑

  • So according to these calculations,

    我們的宇宙只是 眾多宇宙泡沫堆中的一個泡泡

  • we are like campers

    眾多宇宙裡有數以萬計的泡泡

  • who accidentally set their tent

    每個泡泡都是一個不同的宇宙

  • at the edge of a cliff.

    擁有不同的內容物

  • And eventually, the Higgs field

    還有不同的定律

  • will undergo a phase transition

    在這個假設下

  • and matter will collapse into itself.

    我們只能討論確定希格斯質量的可能性

  • So is this how humanity is going to disappear?

    那麼解開謎團的關鍵

  • I don't think so.

    就在這眾多宇宙中的統計特性

  • Our calculation shows that quantum tunneling

    它可能類似沙灘上的沙丘

  • of the Higgs field is not likely to occur

    基本上你可以想像 在沙灘上的任何坡度找到沙丘

  • in the next 10 to the 100 years,

    但是沙丘的坡度通常都在30到35度左右

  • and this is a very long time.

    原因很簡單

  • It's even longer than

    因為風堆起沙子,重力讓沙子掉下來

  • the time it takes for Italy to form a stable government.

    所以大部分的沙丘

  • (Laughter)

    都擁有剛好接近崩塌的斜度

  • Even so, we will be long gone by then.

    類似的事情也可能 發生於眾多宇宙中的希格斯玻色子

  • In about five billion years,

    在眾多宇宙的泡泡中

  • our sun will become a red giant,

    希格斯的質量 可能也在希格斯場接近崩塌的邊緣

  • as large as the Earth's orbit,

    就像在沙丘的例子裡 有兩個互相抗衡的效應一樣

  • and our Earth will be kaput,

    我的故事不會結束

  • and in a thousand billion years,

    因為我們還不知道故事的結局

  • if dark energy keeps on fueling

    科學一直在前進

  • space expansion at the present rate,

    為了解開謎團,我們需要更多數據

  • you will not even be able to see as far as your toes,

    希望LHC不久後 又會為這個故事提供更多新線索

  • because everything around you

    光是發現希格斯玻色子的質量

  • expands at a rate faster than the speed of light.

    就讓我們知道這麼多

  • So it is really unlikely

    我一開始假設 已知的粒子都在宇宙之中

  • that we will be around to see the Higgs field collapse.

    甚至超出我們所知的宇宙

  • But the reason why I am interested

    從這我們發現能跨越時空的希格斯場

  • in the transition of the Higgs field

    可能處在刀鋒 隨時可能引起宇宙崩塌

  • is because I want to address the question,

    我們發現這可能提醒我們

  • why is the Higgs boson mass so special?

    我們的宇宙 只是眾多宇宙沙灘中的一顆沙粒

  • Why is it just right to keep the universe

    但我並不知道我的假設正不正確

  • at the edge of a phase transition?

    這就是物理學的運作方式

  • Theoretical physicists always ask "why" questions.

    一套測量可將我們推向認識宇宙的新路

  • More than how a phenomenon works,

    也可以送我們進死胡同

  • theoretical physicists are always interested in

    但不論結果如何

  • why a phenomenon works in the way it works.

    有一件事我很確定:

  • We think that this these "why" questions

    這趟旅程將會充滿驚喜

  • can give us clues

    謝謝

  • about the fundamental principles of nature.

  • And indeed, a possible answer to my question

  • opens up new universes, literally.

  • It has been speculated that our universe

  • is only a bubble in a soapy multiverse

  • made out of a multitude of bubbles,

  • and each bubble is a different universe

  • with different fundamental constants

  • and different physical laws.

  • And in this context, you can only talk about

  • the probability of finding a certain value of the Higgs mass.

  • Then the key to the mystery

  • could lie in the statistical properties

  • of the multiverse.

  • It would be something like what happens

  • with sand dunes on a beach.

  • In principle, you could imagine to find sand dunes

  • of any slope angle in a beach,

  • and yet, the slope angles of sand dunes

  • are typically around 30, 35 degrees.

  • And the reason is simple:

  • because wind builds up the sand, gravity makes it fall.

  • As a result, the vast majority of sand dunes

  • have slope angles around the critical value,

  • near to collapse.

  • And something similar could happen

  • for the Higgs boson mass in the multiverse.

  • In the majority of bubble universes,

  • the Higgs mass could be around the critical value,

  • near to a cosmic collapse of the Higgs field,