Ever since Einstein it has been a dogma of physics that nothing can exceed the speed of light, and for decades every time the principle has been tested it has been confirmed. Until now. Jason Palmer, Science and Technology reporter at BBC News, has
the story:
Puzzling results from Cern, home of the LHC [Large Hadron Collider], have confounded physicists - because it appears subatomic particles have exceeded the speed of light. Neutrinos sent through the ground from Cern toward the Gran Sasso laboratory 732km away seemed to show up a tiny fraction of a second early.
Neutrinos are so tiny that they can pass through the entire earth without striking a single atom, which enables scientists to send a beam of them in a direct line to the detector some 440 miles away.
The speed of light is the universe's ultimate speed limit, and much of modern physics - as laid out in part by Albert Einstein in his special theory of relativity - depends on the idea that nothing can exceed it. Thousands of experiments have been undertaken to measure it ever more precisely, and no result has ever spotted a particle breaking the limit.
But Dr. Ereditato and his colleagues have been carrying out an experiment for the last three years that seems to suggest neutrinos have done just that.
In the course of doing the experiments, the researchers noticed that the particles showed up a few billionths of a second sooner than light would over the same distance. The team measured the travel times of neutrino bunches some 15,000 times, and have reached a level of statistical significance that, in scientific circles, would count as a formal discovery.
Dr. Ereditato has asked the world scientific community to investigate his result to try to find their error, if there is one, because much of the superstructure of modern physics will need to be revised if the result stands.
But the group understands that what are known as "systematic errors" could easily make an erroneous result look like a breaking of the ultimate speed limit, and that has motivated them to publish their measurements. "My dream would be that another, independent experiment finds the same thing - then I would be relieved," Dr Ereditato said.
But for now, he explained, "we are not claiming things, we want just to be helped by the community in understanding our crazy result - because it is crazy, and of course the consequences can be very serious."
We note in passing that this is a refreshing example of scientific humility. A well-established hypothesis stands to be over-turned but rather than trumpet their revolutionary discovery, the Cern team is asking for confirmation from other investigators or a theoretical explanation that would account for their anomalous result. Would that all scientists were as sober and circumspect in the conclusions they draw from their data.
