“Six thousand billion of them are going through your body every second.” That’s physicist Lawrence Krauss on neutrinos, on the June 15th weekly Science Talk podcast. “Neutrinos are the lightest elementary particles we know of. The name comes from the fact that they had to be neutral because we couldn’t see them in detectors. But they had to be light. So Enrico Fermi called them ‘a little neutron,’ in Italian is neutrino. So they were baby neutrons, which were the only other neutral particles at the time that were known.”
“每秒钟会有六万亿个中微子穿过你的身体。”这是物理学家劳伦斯·克劳斯在6月15日的每周科学讲话节目中提出的有关中微子的论述。“中微子是目前为止我们所知的最轻的基本粒子。由于我们在探测器中观察不到它们，它们一定是中性的，这就是它们名字的由来。并且它们又很轻，所以恩里科·费尔米称它们为‘小中子’，意大利人则叫它中微子。因此，它们是很小的中子，从被发现起就是除了中子以外唯一的中性粒子。”
Now astrophysicists [Shaun Thomas, Ofer Lahav and Filipe Abdalla] have put a best-guess upper limit on the mass of the neutrino. The research is being reported this week at the Weizmann UK conference at University College London and will appear in an upcoming issue of Physical Review Letters.
目前，天体物理学家们已经对中微子的质量上限做出了最好的测定。研究成果将于本周在英国伦敦大学的英伦魏茨曼会议上报导，并将发表在下一期的《物理评论快报》上。
The work took advantage of the huge 3-D galaxy map called Mega Z. Because there are so many neutrinos, their tiny masses add up to influence the overall distribution of galaxies. And the researchers say the galactic map depends on a neutrino’s mass being no more than 0.28 electron volts, less than a billionth of the mass of an atom of hydrogen, the lightest element. “These are the most interesting particles in nature.”
此研究利用了巨大的3D星系地图Mega Z。由于宇宙中有巨量的中微子，尽管其质量极小，但合起来就足以影响到星系的分布。并且，研究人员说，从宇宙星系分布图来推测，中微子的质量最多不超过 0.28电子伏特，比氢原子质量的十亿分之一还要轻，可以说是最轻的微粒了。“事实上，它们是最有趣的粒子。”
来源:可可英语 http://www.kekenet.com/hangye/201201/167426.shtml
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