经济学人82:基础物理 反物质研究突飞猛进

 　　Science and Technology Fundamental physics Antimatter of fact

　　科技 基础物理 反物质研究突飞猛进
　　Researchers at CERN have held on to anti-atoms for a full quarter of an hour
　　欧洲核子研究中心的科研人员让反原子颗粒存在时间长达15分钟
　　READERS who were paying attention in their maths classes may recall that quadratic equations often have two solutions, one positive and one negative.
　　数学课上认真听讲的读者朋友或许都能想起二次方程式通常有两个解:一个是正解,另一个是负解。
　　So when, in 1928, a British physicist 1 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，当英国物理学家保罗·狄拉克(Paul Dirac)在解一道有关微观电子的类似方程时，得到了一个描述电子颗粒负状态的结果，该结果按照异常情况本应该予以舍弃，但实际情况并非如此。
　　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）把这种负粒子解释为反物质，四年后，反物质在真实的实验中出现。
　　Since then antimatter-first, anti-electrons, known as positrons, and then antiversions of all other particles of matter-has become a staple 2 of both real science and the fictional 3 sort.
　　从那以后，反物质研究—首先是反电子，俗称正电子，然后到其它所有物质颗粒的反续状态—成为真实科学和虚拟科学的重要组成部分。
　　What has not been available for study until recently, however, is entire anti-atoms.
　　迄今为止，只有反原子还没有得到全面的研究。
　　A handful have been made in various laboratories, and even held on to for a few seconds.
　　但少数反原子的研究已经在不同实验室展开，有些实验室甚至让反原子存在了几秒种。
　　But none has hung around long enough to be examined in detail because, famously, antimatter and matter annihilate 4 each other on contact.
　　但他们都没有能够让反原子存在更长时间以提供细节观测，众所周知，这是由于反物质和物质在接触过程中会互相湮灭。
　　But that has now changed, with the preservation 5 of several hundred such atoms for several minutes by Jeffrey Hangst and his colleagues at CERN, the main European particle-physics laboratory near Geneva.
　　但现在这种情况已经得到了改观，欧洲原子核研究组织（CERN）—日内瓦附近的欧洲粒子物理研究试验室—的Jeffrey Hangst及其同事已将数百颗这种原子的生命状态持续了几分钟。
　　The reason this is important is that Dirac's equation is misleading.
　　反原子状态不能保留的重要原因在于我们受了狄拉克（Dirac）方程式的误导。
　　Antimatter cannot be the perfect opposite of matter, otherwise neither would exist at all.
　　反物质与物质不可能以完全对等的反状态形式存在，否则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 6 each other long since, leaving only light and other forms of electromagnetic radiation to fill the universe.
　　如果真是那样的话，那么在宇宙大爆炸时期，它们二者生成的数量也应该相同，历经漫长的时间演化，它们早就应该互相湮灭，只留下光线和各种形式的电磁辐射充斥宇宙。
　　That galaxies 7, stars and planets-and physicists 8 to ponder such things-exist therefore means there is a subtle asymmetry 9 between matter and antimatter, and that nature somehow favours the former.
　　因此物理学家认为星系，恒星和行星诸如此类的事物能够存在的原因在于物质与反物质一定存在着一种微妙的非对称性，而自然界偏偏钟爱于前者。
　　Two such asymmetries 10 have indeed been found. But neither is big enough to explain why so much matter has survived.
　　实际上"物质"与"反物质"的非对称性已经在两项试验中被发现，但它们的非对称程度还不足以解释为什么会有大量的"物质"存续下来。
　　Being able to look at entire anti-atoms might give some further clue.
　　通过观察完整的反原子，科学家或许能得到进一步的线索。
　　Last November the ALPHA collaboration 11 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，欧洲原子核研究组织阿尔法合作项目负责人Hangst博士设法将一些正电子分别放入38颗反质子的轨道—这样就产生了反氢原子—然后让它们在电磁阱中存留零点几秒的时间。
　　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).
　　现在，研究人员在自然物理杂志上发表的报告称，他们已经利用设计的装置将反氢子存在时间延续到了16分钟。（在原子物理术语上相当于亿万年）。
　　This gives the anti-atoms plenty of time to settle into their ground state, the most stable condition a particle or atom can attain 12.
　　这给反原子充分的时间进入能量基态，这是粒子或原子所能获得的最稳定状态。
　　As a result, Dr Hangst and his colleagues can look in a leisurely 13 manner for novel ways that antimatter might differ from the common-or-garden variety.
　　因此，Hangst博士及其同事能够寻找新的途径从容地观测反物质可能与普通物质存在的差别。
　　Their first experiment will involve nudging the trapped anti-atoms with microwaves.
　　他们的首次实验将包含用微波对捕获的反原子进行微移。
　　If the frequency of these microwaves is just right, they will flip 14 an anti-atom's spin.
　　如果这些微波的频率恰好正确，它们将会反转反原子的旋转方向。
　　That reverses the polarity of the atom's magnetic field and ejects it from the trap.
　　于是原子的磁场极性被改变并将原子抛出电磁阱。
　　The frequency needed to do this can then be compared with that which flips 15 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.
　　实验所需的频率随后将与反转普通氢原子旋转方向所用频率进行对比，如果两种频率数值不同，将为神秘宇宙的非对称性提供证据。
　　Besides being of huge interest (it would, after all, be a legitimate 16 answer to the question "why are we here?"), such a result would also have a pleasing symmetry of its own.
　　这个研究结果除了非常有趣（它最终会为"人类为什么会存在？"这个问题提供合乎逻辑的答案），该结果的本身也有令人欣喜的对称性。
　　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.
　　当初发现反物质是理论预测未知事实的一个范例，而现在根据反物质的研究发现不对称性的事实则是事实预测了未知理论。