Einstein's theory called into question

Under a mountain range between Italy and Switzerland, one of the core foundations of physics has been rattled by scientists who claim they have observed particles moving faster than the speed of light.

Researchers at the physics laboratory Cern - one of the largest in the world - were due to release a paper this morning (NZ time) which showed they had recorded subatomic particles moving at a speed which Einstein deemed impossible.

The finding, if proved conclusive, would pose numerous unsettling possibilities, not least the scenario in which information could be sent back in time. If a signal could indeed travel faster than the speed of light, it would be received before it was sent.

The Cern scientists shot beams of minuscule particles - called neutrinos - underground from Geneva, Switzerland, to Gran Sasso in Italy.

A beam of light would have made this 730km trip in 2.4 milliseconds. But the scientists said the particles arrived at the destination 60 billionths of a second faster than the speed of light (299,792m per second).

The experiment has run for three years with 15,000 recordings, and despite few errors the researchers were downplaying the astonishing result until it could be verified at other facilities.

University of Auckland physicist David Krofcheck, audibly quivering, said he was "extremely sceptical but extremely excited" about the study.

Asked what it would mean if the finding was proved conclusive, Dr Krofcheck said: "Oh golly, golly, golly ...if this experiment holds true, then Einstein's theory just becomes a mere proximation of some larger theory.

"It wouldn't overthrow Einstein in a practical sense because your GPS navigator will still work in your car, your aeroplane is still going to get where it's going, but from a physics point of view it would be an absolute revolution."

New Zealand physicist Stephen Parke said the Chicago laboratory Fermilab, where he is head theoretician, made a similar finding in 2007 but there was too great a margin of error for it to be proved.

He said there were numerous possibilities for errors when measuring barely detectable matter and making recordings in time-spans of a billionth of a second.

Of the Cern finding, Dr Parke said: "It may be that there's something else going on, that there's some extra-dimensional shortcut to get from A to B. There might be some explanation besides having to give up our fundamental tenets of physics."

Dr Krofcheck said that light followed the path of least resistance through the vacuum of outer space, so if there were mysterious fields - outside of three dimensions and time - in the vacuum, light might be able to divert through those avenues.

He said the Cern study needed to be peer-reviewed and the same process had to be observed by fresh eyes.

But he noted this result had now been observed in at least two experiments, and could not be immediately dismissed as fantasy. Two similar facilities, the MINOS project at Fermilab in Chicago, and the T2K experiment in Japan, will attempt to replicate the Cern finding.

Breakthrough

What they did:

* Scientists fired beams of tiny particles ("neutrinos") a distance of 730km under the ground from Geneva, Switzerland, to Gran Sasso, Italy.

* This trip would take a light beam 2.4 milliseconds to complete.

* The speed at which the neutrinos reached the end point was recorded as 60 billionths of a second faster than the speed of light, with a margin of error of plus or minus 10 billionths of a second.

What it means:

* While this finding is yet to be peer-reviewed, it appears to contradict Einstein's theory of special relativity (E=mc2), which states that nothing can travel faster than the speed of light.