Ian Sample in The Guardian:
But now it seems that researchers working in one of the world's largest physicslaboratories, under a mountain in central Italy, have recorded particles travelling at a speed that is supposedly forbidden by Einstein's theory of special relativity.
Scientists at the Gran Sasso facility will unveil evidence on Friday that raises the troubling possibility of a way to send information back in time, blurring the line between past and present and wreaking havoc with the fundamental principle of cause and effect.
They will announce the result at a special seminar at Cern – the European particle physicslaboratory – timed to coincide with the publication of a research paper (pdf) describing the experiment.
Researchers on the Opera (Oscillation Project with Emulsion-tRacking Apparatus) experiment recorded the arrival times of ghostly subatomic particles called neutrinos sent from Cern on a 730km journey through the Earth to the Gran Sasso lab.
The trip would take a beam of light 2.4 milliseconds to complete, but after running the experiment for three years and timing the arrival of 15,000 neutrinos, the scientists discovered that the particles arrived at Gran Sasso sixty billionths of a second earlier, with an error margin of plus or minus 10 billionths of a second.
The measurement amounts to the neutrinos travelling faster than the speed of light by a fraction of 20 parts per million. Since the speed of light is 299,792,458 metres per second, the neutrinos were evidently travelling at 299,798,454 metres per second.
More here.CERN物理学家声称中微子速度超越光速
+Dante Jiang 写道 "爱因斯坦 1905 年提出的狭义相对论指出，宇宙中任何东西都不可能超越真空中的光速。但是 CERN（欧洲核子研究中心）日内瓦实验室的研究者宣称他们记录下了中微子突破了299792千米/秒 的界限。"实验原理很简单：位于意大利的粒子探测器Oscillation Project with Emulsion-tRacking Apparatus(OPERA)记录瑞士日内瓦CERN发射出的中微子。中微子与其它物质几乎不发生任何交互作用，从CERN到OPERA距离730公里，如果中微子是以光速飞行，那么整个过程将耗时约2.43毫秒（730/299792）。过去三年，OPERA记录了大约16,000个中微子的飞行时间。实验结果显示，中微子的平均速度比预期的快了60纳秒。科学家声称他们测量仪器的误差是正负10纳秒。如果实验得到确认的话，这将是过去半个世纪以来最重要的物理学发现之一。科学家多对此都持怀疑态度，认为可能是系统误差导致的，因为计时依靠的是GPS。
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