物理學之美

It’s 2 a.m. and I’m wide awake. One’s sense of time lapses in this 1）subterranean world of 2）optics laboratories in the basement of the University of Toronto’s physics building.

There’s a 20-second rhythm to this experiment， a carefully controlled sequence of 3）shutters opening and closing for laser beams， of mechanical switches sending 4）electrical currents to 5）magnetic field coils， of green waveforms appearing on the 6）oscilloscope screen as 7）radio frequency fields manipulate.

Many people have worked to fill this room with the machines necessary to make these 2，000 atoms of 8）rubidium cold enough to enter into the 9）quantum mechanical world. Once there， these atoms stop behaving as individuals and start acting together， as if in a community， in a new phase of matter we call a 10）Bose-Einstein condensate.

Four hours ago， I saw a hint that this behaviour continued even as I split the cloud in two pieces， and that’s neat. It means the quantum mechanics I teach to undergraduates really works. And I want to see more.

I often wonder how I came to be here. It wasn’t 11）the straight and narrow path that may seem obvious to anyone who knows my past. I was probably the best student in my kindergarten class. I graduated at the top of my junior high class， and again in high school. School was what I was good at， and math and science were what I loved most. My father’s influence， and the practicality of a real job， led me into engineering as an undergraduate， where I continued to be better at writing exams than my colleagues. I graduated at the top of my class at university， too.

When I finished my undergraduate studies， I froze. I didn’t know what to do with my life. I’d done exactly everything I’d ever hoped for， which was going to university. Two choices were before me： I could continue studying at the graduate level or I could start teaching others about the things I found most interesting， probably at the high-school level.

The first， I knew， would satisfy my hunger for learning， though would leave me feeling like my time was spent in selfish pursuit of some small piece of knowledge that had little bearing on the quality of anyone’s life. The second， I knew， would be rewarding and would allow me to be a role model， but I feared I would be wasting some talent I had been given. This conflict， this decision， 12）paralyzed me， and in the end I decided to do nothing. I hadn’t done nothing in such a long time and a whole year of it was what I needed.

Nothing wasn’t quite nothing. I spent a year volunteering with elementary-school students in the mornings and homeless people in the winter evenings. I also worked part-time for a few months with an organization devoted to the promotion of women in science and engineering.

The chair of this organization was an amazing woman， a professor near retirement who devoted much of her time to the organization and the promotion of science to children， while maintaining an outstanding reputation as a scientist in her field. Though I didn’t realize it at the time， I think it was seeing this woman pursuing what she loved， while still sharing her passion and encouraging others， that keeps me in the lab at 2 a.m. on a Thursday.

The decision was one of those funny ones. I was sitting in my living room one cold January night during my year of nothingness and I just knew. I knew I wanted to go to grad school. My choice was as clear that day as it could have been， and it never wavered after that moment. I sent in my applications to two Canadian universities， I chose one and， five years later， I have a master’s degree and am working on my 13）PhD.

The question of whether what I’m doing is useful still pokes its head out every once in a while. But it doesn’t bother me like it once did. I’ve realized， as my studies delve deeper and deeper， that these things are worth knowing， even if I’m the only one that ever knows them.

Physics is worth knowing because it is beautiful. It is the hidden secret of the scientist. We may claim to be researching some topic or other because it is “useful to society” or it will revolutionize some technology but， more often than not， we are simply fascinated by some small detail about how the world works and we can’t stop thinking about it until we understand it better. We are constantly astounded by the way a few basic principles work together to explain so many different things， and sit in wonder and awe at the beauty of the world. Like an artist， I want to share this beauty with others. I want them to know what it is to see through my eyes.

And so， now that it’s almost 3 a.m.， the question of what I’m doing here isn’t so curious. My experiment continues to click away in its 20-second rhythm， as my computers collect data revealing the behaviour of a tiny cloud of atoms， behaviour that will help me understand the nature of my world. And if it doesn’t quite work， my colleagues will come in and we’ll try again tomorrow.

現(xiàn)在是凌晨兩點，而我卻很清醒。在多倫多大學物理樓地庫光學實驗室這個地下工作環(huán)境里，人的時間感會失效。

這項實驗的時間節(jié)奏是20秒鐘，一系列精密操控的實驗包括：對應激光束的快門開合、機械開關對磁場線圈發(fā)送的電流、無線電射頻場起作用時示波屏上顯示的綠色波形。

很多人的努力之下，這個房間才得以布滿各種必需的裝置，讓這2000個銣元素原子達到足夠的冷卻程度進入量子力學世界。一旦達到那個溫度，這些原子便停止了各自的個體行為，開始共同行動，就像在一個集體里似的，進入一種新的物質狀態(tài)，我們稱之為“玻色—愛因斯坦凝聚態(tài)”。

四個小時前，我看到即使在我把該冷原子團切割成兩份后這種行為仍然持續(xù)的跡象，而且很整齊。這意味著我向本科生們講授的量子力學的確起作用。于是我想再進一步探究。

我經(jīng)常好奇自己是如何走到這一步的。事實并不像任何了解我過去的人從表面上看到的那么順當通暢。我很可能曾是幼兒園班上最優(yōu)秀的孩子。我以班上最優(yōu)的成績從初中畢業(yè)，還有之后的高中。讀書是我擅長的事，而數(shù)學和科學是我最愛的科目。由于父親的影響，出于要找一份真正工作的實際考慮，我本科選了工程學專業(yè)，當時我的書面考試一直優(yōu)于其他同學。再一次，我以全班最好的成績從本科畢業(yè)。

當我大學本科畢業(yè)后，我愣住了。我不知道接下來的人生要怎么走。我完成了自己一直期望的所有事情，那就是上大學。我面前出現(xiàn)了兩個選擇：我可以繼續(xù)攻讀研究生，又或者是開始教學工作，將我認為最有意思的東西教給大概是高中水平的人。

第一個選擇，我知道，能夠滿足我的求知欲，但會給我留下一種感覺，覺得這是把時間花在滿足個人對知識的一些高尖枝節(jié)的自私追求上，而對他人的生活質量關聯(lián)甚少。第二個選擇，我知道，將會給我?guī)韴蟪辏⑹刮页蔀樾袨榘駱?，但我害怕那會浪費了我的某些天賦。這種矛盾，這個決定，使我麻痹喪志，結果最后我決定什么都不做。我在很長一段時間里無所作為，而當中有一整年的放空正是我所需要的。

事實上也不是什么都沒做。我花了一年的時間做義工，早上和小學生在一起，冬夜則和無家可歸者待在一起。我還在一家致力于推動婦女參與科學和工程學事業(yè)的組織做了幾個月的兼職。

該組織的主席是一位讓人驚嘆的女士：她是一位快要退休的教授，一直把大量的時間奉獻到該組織以及推動兒童參與科學的事業(yè)中，同時還一直是她自己領域里的一位杰出科學家。雖然當時我并未意識到，但我想正是因為看到這位女士追求自己熱愛的事業(yè)，并將她的熱情與人分享，鼓舞他人，才使得我能夠在某個星期四在實驗室里待至凌晨兩點。

這個決定是我那些奇怪決定中的一個。那是個寒冷的一月夜晚，在我無所事事的那一年里，我當時坐在客廳里，然后突然靈光一閃。我知道我想讀研究生。那天做的這個決定非常明確，并從此毫無動搖過。我向兩所加拿大大學遞交了申請，并選擇了其中一所，五年后，我獲得了碩士學位，如今正在攻讀博士學位。

那個關于我目前所做的事是否具有實際意義的問題依然會時不時地從我的腦海里冒冒頭。但它從來都無法像當初那樣干擾到我。我已深知，當我的鉆研工作走得越深入，這些知識被了解的價值就會更加明確，即使我是唯一認識這些價值的人。

物理學是值得去了解的，因為那是如此之美。它是科學家隱藏的秘密。我們可能會聲稱對某些課題進行研究是因為它是“對社會有益的”，又或是它將帶來某種技術的變革，但其實很多時候都不是這樣的，我們只不過是對一些關于世界運行的微小細節(jié)著迷不已，無法停止對其思考，直到我們能更好地理解它們?yōu)橹埂Ｒ恍┗镜脑硐嗷プ饔帽憧山忉屇敲炊嗖煌氖挛?，我們時常為之感到震驚，并對這個世界的美感到驚嘆又敬畏。就如藝術家那樣，我想與他人分享這種美。我希望人們能通過我的雙眼了解其美態(tài)。

所以，現(xiàn)在快凌晨三點了，我在這里做什么，這已經(jīng)不是什么難解疑團了。我的實驗還在按著它那20秒鐘的循環(huán)規(guī)律進行著，同時我的電腦收集著揭示這些細微冷原子團的行為數(shù)據(jù)，這些行為將有助于我更好地理解我的世界的本質。如果行不通的話，我的同事會加入進來，然后明天我們會再繼續(xù)嘗試。