Published February 23, 2012
A loose connection between a timer and a computer led some of the world’s smartest particle physicists to conclude that certain tiny particles called neutrinos moved faster than the speed of light -- a declaration that shocked the science world and would have called into questions Einstein’s theories.
But rather than invalidating the stunning superspeed finding, the flaw may have led scientists to underestimate it.
Citing sources familiar with the experiment, Science magazine’s website reported Wednesday that the 60-nanoseconds discrepancy that led to the startling speed conclusion came from a bad connection in a fiber optic cable connecting a GPS receiver (used to correct the timing of the neutrinos' flight) and a computer.
After tightening the connection and then remeasuring the time it takes data to travel the length of the cable, researchers found that the data arrive 60 nanoseconds earlier than assumed, the website said. (More data will be needed to confirm this hypothesis.)
Yet a Thursday morning statement from CERN's OPERA team, the European science group that first reported the faster-than-light finding, noted that the faulty cable could have led to an undercalculation instead.
Neutrinos could move even faster than the speed of light than previously suggested, in other words.
"The optical fiber connector ... brings the external GPS signal to the OPERA master clock," explained the science lab, and it "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."
A second issue with the study involves an oscillator used to provide the time stamps for the GPS synchronization. Flaws with that gadget may have led to an overestimate of speeds -- keeping neutrinos in line with Einstein's theories.
Needless to say, CERN plans new tests.
"The potential extent of these two effects is being studied by the OPERA collaboration. New measurements with short pulsed beams are scheduled for May," the science team said.
Einstein theorized that the speed of light in a vacuum -- approximately 186,280 miles per second, or about 700 million miles per hour -- is an absolute speed limit, and used the value in his famous formula, E = mc2.
Rewriting the theories based on this speed limit would have made an array of science fiction ideas more plausible -- even time travel -- yet that's exactly what scientists said last year, stunning the science community.
The theory that some tiny bits of matter were whizzing along faster than Einstein thought possible was announced in Sept. 2011, when physicists with the CERN lab in Switzerland said they observed neutrinos completing a 454-mile racecourse faster than a beam of light would.
When announcing their follow-up finding in November, scientists at the Italian Institute for Nuclear Physics (INFN) said that their tests were intended to exclude one potential effect that may have affected the original measurement.
"A measurement so delicate and carrying a profound implication on physics requires an extraordinary level of scrutiny," said Fernando Ferroni, president of the INFN.
Apparently, yet more scrutiny was required.
"It's very hard to find an error by reading a paper," particle physicist Rob Roser of the Fermi National Accelerator Laboratory (Fermilab) in Batavia, Ill., said Friday at an annual science meeting.
"What you need is for someone else to make the measurement. We'll see what happens."