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Science and Technology Fundamental physics Antimatter of fact
科技 基礎物理 反物質研究突飛猛進
Researchers at CERN have held on to anti-atoms for a full quarter of an hour
歐洲核子研究中心的科研人員讓反原子顆粒存在時間長達15分鐘
READERS who were paying attention in their maths classes may recall that quadratic equations often have two solutions, one positive and one negative.
數學課上認真聽講的讀者朋友或許都能想起二次方程式通常有兩個解:一個是正解,另一個是負解。
So when, in 1928, a British physicist called Paul Dirac solved such an equation relating to the electron, the fact that one answer described the opposite of that particle might have been brushed aside as a curiosity.
因此1928年，當英國物理學家保羅·狄拉克(Paul Dirac)在解一道有關微觀電子的類似方程時，得到了一個描述電子顆粒負狀態的結果，該結果按照異常情況本應該予以舍棄，但實際情況并非如此。
But it wasn't. Instead, Dirac interpreted it as antimatter-and, four years later, it turned up in a real experiment.
狄拉克（Dirac）把這種負粒子解釋為反物質，四年后，反物質在真實的實驗中出現。
Since then antimatter-first, anti-electrons, known as positrons, and then antiversions of all other particles of matter-has become a staple of both real science and the fictional sort.
從那以后，反物質研究—首先是反電子，俗稱正電子，然后到其它所有物質顆粒的反續狀態—成為真實科學和虛擬科學的重要組成部分。
What has not been available for study until recently, however, is entire anti-atoms.
迄今為止，只有反原子還沒有得到全面的研究。
A handful have been made in various laboratories, and even held on to for a few seconds.
但少數反原子的研究已經在不同實驗室展開，有些實驗室甚至讓反原子存在了幾秒種。
But none has hung around long enough to be examined in detail because, famously, antimatter and matter annihilate each other on contact.
但他們都沒有能夠讓反原子存在更長時間以提供細節觀測，眾所周知，這是由于反物質和物質在接觸過程中會互相湮滅。
But that has now changed, with the preservation of several hundred such atoms for several minutes by Jeffrey Hangst and his colleagues at CERN, the main European particle-physics laboratory near Geneva.
但現在這種情況已經得到了改觀，歐洲原子核研究組織（CERN）—日內瓦附近的歐洲粒子物理研究試驗室—的Jeffrey Hangst及其同事已將數百顆這種原子的生命狀態持續了幾分鐘。
The reason this is important is that Dirac's equation is misleading.
反原子狀態不能保留的重要原因在于我們受了狄拉克（Dirac）方程式的誤導。
Antimatter cannot be the perfect opposite of matter, otherwise neither would exist at all.
反物質與物質不可能以完全對等的反狀態形式存在，否則任何一方都不可能存留。
If they truly were perfect opposites, equal amounts of the two would have been made in the Big Bang, and they would have annihilated each other long since, leaving only light and other forms of electromagnetic radiation to fill the universe.
如果真是那樣的話，那么在宇宙大爆炸時期，它們二者生成的數量也應該相同，歷經漫長的時間演化，它們早就應該互相湮滅，只留下光線和各種形式的電磁輻射充斥宇宙。
That galaxies, stars and planets-and physicists to ponder such things-exist therefore means there is a subtle asymmetry between matter and antimatter, and that nature somehow favours the former.
因此物理學家認為星系，恒星和行星諸如此類的事物能夠存在的原因在于物質與反物質一定存在著一種微妙的非對稱性，而自然界偏偏鐘愛于前者。
Two such asymmetries have indeed been found. But neither is big enough to explain why so much matter has survived.
實際上"物質"與"反物質"的非對稱性已經在兩項試驗中被發現，但它們的非對稱程度還不足以解釋為什么會有大量的"物質"存續下來。
Being able to look at entire anti-atoms might give some further clue.
通過觀察完整的反原子，科學家或許能得到進一步的線索。
Last November the ALPHA collaboration at CERN, which Dr Hangst leads, managed to put positrons into orbit around 38 antiprotons-thus creating anti-hydrogen atoms-and then held on to them in a magnetic trap for a few tenths of a second.
去年11月，歐洲原子核研究組織阿爾法合作項目負責人Hangst博士設法將一些正電子分別放入38顆反質子的軌道—這樣就產生了反氫原子—然后讓它們在電磁阱中存留零點幾秒的時間。
Now, as they report in Nature Physics, the researchers have used their device to preserve anti-hydrogen for 16 minutes (aeons in atomic-physics terms).
現在，研究人員在自然物理雜志上發表的報告稱，他們已經利用設計的裝置將反氫子存在時間延續到了16分鐘。（在原子物理術語上相當于億萬年）。
This gives the anti-atoms plenty of time to settle into their ground state, the most stable condition a particle or atom can attain.
這給反原子充分的時間進入能量基態，這是粒子或原子所能獲得的最穩定狀態。
As a result, Dr Hangst and his colleagues can look in a leisurely manner for novel ways that antimatter might differ from the common-or-garden variety.
因此，Hangst博士及其同事能夠尋找新的途徑從容地觀測反物質可能與普通物質存在的差別。
Their first experiment will involve nudging the trapped anti-atoms with microwaves.
他們的首次實驗將包含用微波對捕獲的反原子進行微移。
If the frequency of these microwaves is just right, they will flip an anti-atom's spin.
如果這些微波的頻率恰好正確，它們將會反轉反原子的旋轉方向。
That reverses the polarity of the atom's magnetic field and ejects it from the trap.
于是原子的磁場極性被改變并將原子拋出電磁阱。
The frequency needed to do this can then be compared with that which flips the spin of an ordinary hydrogen atom. If the two turn out to be different, it will point towards the nature of the mysterious cosmic asymmetry.
實驗所需的頻率隨后將與反轉普通氫原子旋轉方向所用頻率進行對比，如果兩種頻率數值不同，將為神秘宇宙的非對稱性提供證據。
Besides being of huge interest (it would, after all, be a legitimate answer to the question "why are we here?"), such a result would also have a pleasing symmetry of its own.
這個研究結果除了非常有趣（它最終會為"人類為什么會存在？"這個問題提供合乎邏輯的答案），該結果的本身也有令人欣喜的對稱性。
The original discovery of antimatter was a nice example of theory predicting an undiscovered fact. This would be a fact that repaid the compliment by predicting an undiscovered theory.
當初發現反物質是理論預測未知事實的一個范例，而現在根據反物質的研究發現不對稱性的事實則是事實預測了未知理論。
