Faster-Than-Light Neutrinos Caused by Loose Cable?
A dodgy connection between a GPS unit and atomic clock may be the real reason neutrinos appeared to travel at superluminal speeds.
UPDATE: 6:50 p.m. ET: Nature News Blog reports that the OPERA collaboration has released an official statement that stops short of blaming a loose cable for the erroneous results, but indicates there were two possible errors in the "faster than light" neutrino experiment. Read more.
ORIGINAL: Last year, scientists from CERN caused a sensation when they went public with some very preliminary results suggesting they'd measured neutrinos traveling faster than the speed of light.
"Impossible!" Screamed the critics. "This could be new physics!" Urged supporters. "EINSTEIN WAS WRONG!!!" Cried the tabloid headlines.
However, today, unconfirmed (and I'll repeat this for the tabloid press: unconfirmed) reports suggest what many critics have been thinking all along: The faster-than-light results may have been down to instrumental error and not due some weird quirk, bend, warp or loop in spacetime. Nature, you can breathe a sigh of relief... for now.
The story began in September 2011 when scientists of the OPERA collaboration in Italy went on the record to tell the world - before they'd published any peer-reviewed papers - they'd timed neutrinos traveling from CERN (near Geneva, Switzerland) to the Gran Sasso laboratory (near L'Aquila, Italy) 60 nanoseconds quicker than they should have done.
The fastest anything can travel - according to Einstein's bedrock theory of special relativity - is the speed of light. Nothing, not even the zippy neutrino (or even the shiny red Corvette in your driveway), can break this fundamental speed barrier. Put simply, that's not how the Universe works.* The OPERA scientists tried to account for any error, but couldn't find anything wrong with their experiment. This is why they went public - causing all the "EINSTEIN WAS WRONG!!!" headlines - to ask the scientific community to look at their results and find something they were overlooking. This unorthodox way of "doing science" drew some fire from some critics in the science media, but I'd argue that it gave the world a rare glimpse into science at the very limits of our understanding.
Sadly, it might be less "new physics" and more "dodgy wiring," according to the AAAS Science Insider blog:
According to sources familiar with the experiment, the 60 nanoseconds discrepancy appears to come from a bad connection between a fiber optic cable that connects to the GPS receiver used to correct the timing of the neutrinos' flight and an electronic card in a computer.
Basically, after researchers tightened the suspect cable and measured how long a signal took to travel along it, they found it may account for the 60 nanosecond discrepancy in the neutrino travel time.
So what's next? According to Ars Technica, "researchers are preparing to gather new data with the clocks properly hooked into computers, which should definitively indicate whether the loose connection was at fault."
So, watch this space, I doubt we've heard the last of this very public scientific debate.
*Disclaimer: Just because the "faster-than-light" results defied our current understanding of the Universe doesn't mean scientists weren't excited about the possibility of discovering some quirk of Nature (or "new physics") - on the contrary, one of the main rationales behind the Large Hadron Collider is to seek out new physics. But when it comes to extraordinary claims, there had better be some extraordinary evidence to back them up.
Image: Light-speed? Or loose-wiring? (Corbis)