Faster than light
Researchers from the international accelerator institutes CERN and Gran Sasso have measured particles that move faster than light. They announced that on Friday 23 September during a seminar at CERN, which could be followed via webcast.cern.ch. As this result is highly unexpected and revolutionary in nature, independent measurements from others are now needed. That is why the researchers decided to disclose the results at this stage.
"If this is confirmed then it really will be revolutionary: a completely unexpected and unplanned discovery with enormous implications. In terms of importance this rivals Einstein's theory of relativity. This is what makes curiosity-driven research so much fun! And the actual measurement is almost too simple to explain. That is something you rarely see in my discipline", responds Frank Linde, director of the FOM Institute for Subatomic Physics Nikhef to the latest news from CERN.
The measurement was made as follows: CERN produced a beam of neutrinos and sent these to the Italian OPERA detector 730 km away in the Gran Sasso laboratory. Researchers measured the travel time of the neutrinos. This was found to be 60 nanoseconds faster than light. The researchers admit that a search for systematic errors must now be made. That will in part be done by other accelerator institutes in Japan and the United States. Should the result remain intact then that will be a revolution and exactly what physicists are waiting for: a completely unexpected discovery.
Press release CERN
Update 23 February 2012
CERN press statement
The OPERA collaboration has informed its funding agencies and host
laboratories that it has identified two possible effects that could
have an influence on its neutrino timing measurement. These both require
further tests with a short pulsed beam. If confirmed, one would
increase the size of the measured effect, the other would diminish it.
The first possible effect concerns an oscillator used to provide the
time stamps for GPS synchronizations. It could have led to an
overestimate of the neutrino's time of flight. The second concerns the
optical fibre connector that brings the external GPS signal to the OPERA
master clock, which may not have been functioning correctly when the
measurements were taken. If this is the case, it could have led to an
underestimate of the time of flight of the neutrinos. The potential
extent of these two effects is being studied by the OPERA collaboration.
New measurements with short pulsed beams are scheduled for May.
Update 11 June 2012
Neutrinos sent from CERN to Gran Sasso respect the cosmic speed limit
At the 25th
International Conference on Neutrino Physics and
Astrophysics in Kyoto today, CERN Research Director Sergio Bertolucci
presented results on the time of flight of neutrinos from CERN to the
Gran Sasso laboratory on behalf of four experiments situated at Gran
Sasso. The four, Borexino, ICARUS, LVD and OPERA all measure a neutrino
time of flight consistent with the speed of light. This is at odds with a
measurement that the OPERA collaboration put up for scrutiny last
September, indicating that the original OPERA measurement can be
attributed to a faulty element of the experiment’s fibre optic timing
"Although this result isn’t as exciting as some would have liked,"
is what we all expected deep down. The story captured the public
imagination, and has given people the opportunity to see the scientific
method in action – an unexpected result was put up for scrutiny,
thoroughly investigated and resolved in part thanks to collaboration
between normally competing experiments. That’s how science moves
Press statement on the CERN website