A team of scientists at CERN (European Organization for Nuclear Research) has recorded neutrino particles travelling faster than the speed of light.
The speed of light is a very important fact of physics because at 299,792,458 meters per second it is considered to be the maximum speed at which any matter or energy in the universe can travel. Therefore, for neutrinos to surpass this speed, it brings into question the very laws of physics and the discoveries of the founding fathers of science, especially Albert Einstein, who in 1905 established that the speed of light could not be surpassed by anything in the universe.
THE NEUTRINO RACE
Neutrinos are electrically neutral particles. They have a minuscule mass and pass through almost any material as though it was not there. Over the past 3 years, the scientists working at CERN particle physics centre on the Franco-Swiss border have found that the neutrinos move 60 nanoseconds faster than light over the 730 km distance between Geneva and Gran Sasso, Italy.
The speed of light is 299,792,458 metres per second whereas the neutrinos are evidently travelling at 299,798,454 metres per second. Researchers of the Opera (Oscillation Project with Emulsion-Tracking Apparatus) experiment recorded the arrival times of the neutrinos that were received from CERN. The light beam took 2.4 milliseconds to travel the distance between two locations. But after 3 years of experimentation, the scientists found that the 15, 000 neutrinos that arrived with the light beam at Gran Sasso, were sixty billionths of a second earlier that the photons (light particles), with an error margin of plus or minus 10 billionths of a second.
The measurement amount to the neutrinos travelling faster than the speed of light by a fraction of 20 parts per million. The coordinator of OPERA, Antonio Ereditato, told Reuters, last Thursday: “We have high confidence in our results. But we need other colleagues to do their tests and confirm them.
“When you get such a result you want to make sure you made no mistakes, that there are no nasty things going on you didn’t think of. We spent months and months doing checks and we have not been able to find any errors.?
Clocking the trip of a neutrino requires the measurement of? the distance of the journey and the time it takes for the distance to be covered. Dario Auterio, the head of the neutrino research and spokesman for the group, detailed the extraordinary lengths his team took to ratchet up the accuracy of those measurements. French, Japanese and Italian governments are funding 160 physicists from 11 countries to work on the OPERA experiment. They have spend six months in various cross-checks.
The process of cross-checking began with Global Positioning System measurements. The readings were then upgraded and the scientists measured the distance traveled and factored in the rotation of the Earth, which moves ever so slightly in the flash it takes neutrinos to zoom that far. Traffic in a tunnel running through Gran Sasso mountain was also halted to calibrate their instruments.
Subir Sarkar, head of particle theory at Oxford University said: “If this is proved to be true it would be a massive, massive event. It is something nobody was expecting.?
The findings are so ground-breaking that the OPERA group said it hoped the physics community would scrutinise the result and help uncover any flaws in the measurement, or verify it with their own experiments. A discovery can be claimed if the chances of the results being obtained by physicists are greater than five standard deviations, or less than one in a few million. The Gran Sasso team’s result is six standard deviations.
“Whenever you touch something so fundamental, you have to be much more prudent,” Eraditato commented over his team?s observation has statistical significance. The Opera experiment detects neutrinos as they strike 150,000 “bricks” of photographic emulsion films interleaved with lead plates.
The senior lecturer in particle astrophysics at Sheffield University, Susan Cartwright said: “Neutrino experimental results are not historically all that reliable, so the words ‘don’t hold your breath’ do spring to mind when you hear very counter-intuitive results like this.”
RECONFIRMING THE FINDINGS
For more than a century, skeptics have tried to find cracks in Einstein?s work. “It’s dangerous to lay odds against Einstein,” said Rob Plunkett, a physicist at the Fermilab near Chicago who has tried similar speed-of-light experiments. Harvard University science historian Peter Galison said Einstein’s relativity theories have been greatly challenged, but they have survived.
Two experiments will be held, one known as as T2K in Japan and MINOS near Chicago in the US where the findings at CERN will hopefully be replicated. The MINOS experiment saw hints of neutrinos moving at speeds faster than the speed of light in 2007 but were not able to confirm it.
Cartwright works on T2K, which sends neutrinos over a 295km distance. “We could certainly check this, but MINOS [the neutrino experiment at Fermilab in the US] are in a better position because we are still doing repairs after the earthquake that struck Japan.”
A spokesperson for the MINOS neutrino experiment, Professor Jenny Thomas of University College London said if the discovery was proved correct, it “would overturn everything we thought we understood about relativity and the speed of light”.
THE TWIST IN SCIENCE
Many are excited by the findings. Alan Kostelecky, an expert in the possibility of faster-than-light processes at Indiana University, told the Guardian that the results would be difficult to accept till they could be backed with further research. In 1985, Kostelecky and his colleagues put forward a theory that neutrinos could in fact travel faster than the speed of light by interacting with an unknown field that lurks in the vacuum. “With this kind of background, it is not necessarily the case that the limiting speed in nature is the speed of light,” he said. “It might actually be the speed of neutrinos and light goes more slowly.”
Kostelecky added: “If this is confirmed, this is the first evidence for a crack in the structure of physics as we know it that could provide a clue to constructing such a unified theory.?
In an attempt to explain the recent findings, Heinrich Paes, a physicist at Dortmund University, has developed another theory. The neutrinos may be taking a shortcut through space-time, by travelling from CERN to Gran Sasso through extra dimensions. “The extra dimension is warped in a way that particles moving through it can travel faster than particles that go through the known three dimensions of space. It’s like a shortcut through this extra dimension. So it looks like particles are going faster than light, but actually they don’t.”
“If the neutrinos have broken the speed of light, it would overturn a keystone theory from the last century of physics,? says Professor Jim Al-Khalili at the University of Surrey. ?That’s possible, but it’s far more likely that there is an error in the data. ?
No experiment since Einstein’s death has broken the speed limit of light. The ?anomaly?, as it was called by physicist, Auterio, is phenomenal and it could break or bend the rules on which decades of research have been based on.
Sources: Guardian, Reuters, The Washington Post, CERN