The Glade 4.0

GENEVA (AP) -- Scientists at the world's largest physics lab say they have clocked subatomic particles traveling faster than light, a feat that - if true - would break a fundamental pillar of science.

The readings have so astounded researchers that they are asking others to independently verify the measurements before claiming an actual discovery.

"This would be such a sensational discovery if it were true that one has to treat it extremely carefully," said John Ellis, a theoretical physicist at the European Organization for Nuclear Research, or CERN, who was not involved in the experiment.

Nothing is supposed to move faster than light, at least according to Albert Einstein's special theory of relativity: The famous E (equals) mc2 equation. That stands for energy equals mass times the speed of light squared.

But neutrinos - one of the strangest well-known particles in physics - have now been observed smashing past this cosmic speed barrier of 186,282 miles per second (299,792 kilometers).

CERN says a neutrino beam fired from a particle accelerator near Geneva to a lab 454 miles (730 kilometers) away in Italy traveled 60 nanoseconds faster than the speed of light. Scientists calculated the margin of error at just 10 nanoseconds, making the difference statistically significant. But given the enormity of the find, they still spent months checking and rechecking their results to make sure there was no flaws in the experiment.

The CERN researchers are now looking to the United States and Japan to confirm the results.

A similar neutrino experiment at Fermilab near Chicago would be capable of running the tests, said Stavros Katsanevas, the deputy director of France's National Institute for Nuclear and Particle Physics Research.

Katsanevas, who participated in the CERN experiment, said help could also come from the T2K experiment in Japan, though that is currently on hold after the country's devastating earthquake and tsunami in March.

Scientists agree if the results are confirmed, that it would force a fundamental rethink of the laws of nature, starting with the special theory of relativity proposed by Einstein in 1905.

Special relativity, which helps explain everything from black holes to the Big Bang theory about the origins of the universe, underlies "pretty much everything in modern physics," Ellis said. "It has worked perfectly up until now."

He cautioned that the neutrino researchers would also have to explain why similar results weren't detected before, such as when an exploding star - or supernova - was observed in 1987.

Most people online are interested in physics the same way they're interested in science fiction. Frankly, if you can't wrap your brain around projectile motion, you have no business talking about quantum mechanics.

...although the detectors in Italy can pinpoint the neutrinos' time of arrival to within nanoseconds, it's less clear when they left the accelerator at CERN. The neutrinos are produced by slamming protons into a bar-shaped target, sparking a cascade of subatomic particles. If the neutrinos were produced at one end of the bar rather than the other, it could obscure their time of flight.

Sher also mentions a third option: that the measurement is correct. Some theories posit that there are extra, hidden dimensions beyond the familiar four (three of space, one of time). It's possible that the speedy neutrinos tunnel through these extra dimensions, reducing the distance they have to travel to get to the target. This would explain the measurement without requiring the speed of light to be broken.

TheRiov: You're arguing against 4 years of research by leading experts who say the margin of error was extremely low on an experiment they performed many times over. Good luck on that.

The margin of error is a statistic expressing the amount of random sampling error in a survey's results. The larger the margin of error, the less faith one should have that the poll's reported results are close to the "true" figures; that is, the figures for the whole population. Margin of error occurs whenever a population is incompletely sampled.

A good scientist when handling peer review of a fundamental change of this magnitude would say "I found something that we think should be wrong - please help me find any mistakes we have made."

The search for errors is not yet over, according to Jacques Martino, director of the National Institute of Nuclear and Particle Physics at CNRS. He said that more checks would be under way in future, including ensuring that the clocks at Cern and Gran Sasso were properly synchronised, perhaps by using an optical fibre as opposed to the GPS system used at the moment.

This would remove any potential errors that might occur due to the effects of Einstein's theory of general relativity, which says that clocks tick at different rates depending on the amount of gravitational force they experience – clocks closer to the surface of the Earth tick slower than those further away.

Even a tiny discrepancy between the clocks at Cern and Gran Sasso could be at the root of the faster-than-light results seen in September.

A good scientist when handling peer review of a fundamental change of this magnitude would say "I found something that we think should be wrong - please help me find any mistakes we have made."

We have learned a lot from experience about how to handle some of
the ways we fool ourselves. One example: Millikan measured the
charge on an electron by an experiment with falling oil drops, and
got an answer which we now know not to be quite right. It's a
little bit off, because he had the incorrect value for the
viscosity of air. It's interesting to look at the history of
measurements of the charge of the electron, after Millikan. If you
plot them as a function of time, you find that one is a little
bigger than Millikan's, and the next one's a little bit bigger than
that, and the next one's a little bit bigger than that, until
finally they settle down to a number which is higher.

Why didn't they discover that the new number was higher right away?
It's a thing that scientists are ashamed of--this history--because
it's apparent that people did things like this: When they got a
number that was too high above Millikan's, they thought something
must be wrong--and they would look for and find a reason why
something might be wrong. When they got a number closer to
Millikan's value they didn't look so hard. And so they eliminated
the numbers that were too far off, and did other things like that.
We've learned those tricks nowadays, and now we don't have that
kind of a disease.

Doubts cast on faster-than-light neutrinos experiment

Measurements by Gran Sasso physicists suggest neutrinos cannot have travelled faster than the speed of light

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Ian Sample, science correspondent
* guardian.co.uk, Monday 21 November 2011 14.44 EST
* Article history

Subatomic Neutrino Tracks
Neutrons travelling faster than light should theoretically shed electrons and positrons, according to physicists. Photograph: Dan Mccoy /Corbis

The idea that subatomic particles can travel faster than the speed of light in contravention of the currently accepted laws of physics has been dealt a serious blow by researchers who share the lab of the team that made the original finding.

In September, physicists working on an experiment called Opera at the Gran Sasso laboratory in Italy announced that neutrinos sent there from Cern near Geneva seemed to complete the 450 mile (720km) journey faster than a beam of light.

The group went on to refine their experiment and reported on Friday that the ghostly particles still appeared to be breaking nature's speed limit in a troubling violation of Einstein's theory of special relativity that would allow information to be sent back in time and so play havoc with the principle of cause and effect.

But measurements by a competing team of physicists at the Gran Sasso laboratory now suggest the neutrinos cannot have travelled faster than the speed of light as they hurtled through the Earth from Switzerland to the Gran Sasso lab near Rome in central Italy.

The team, who work on an experiment called Icarus, tested an argument described in a recent paper by Andrew Cohen and Sheldon Glashow at Boston University, who claimed that faster-than-light or "superluminal" neutrinos would lose energy by spewing out electrons and their antimatter partners, called positrons. Professor Glashow shared the Nobel prize for physics in 1979.

When Maddalena Antonello and others on the Icarus team analysed the energy of the neutrinos arriving at Gran Sasso, they found no evidence that they had lost energy the way Cohen and Glashow predicted. The finding has bolstered the view of many physicists who believe the Opera result is an error of measurement.

"Cohen and I argue that superluminal neutrinos ... must produce electron–positron pairs. They do not ...Thus, we conclude that the neutrinos are NOT superluminal," Prof Glashow told the Guardian. He went on to add that if neutrinos did travel faster than light "we would have to abandon much of what we think we know, much more than 'just' special relativity."

Jim Al-Khalili, a professor of physics at the University of Surrey who pledged to eat his boxer shorts live on television if the Opera result was proved true, was similarly sceptical that neutrinos can move faster than light.

"Opera measures the time of neutrino travel and hence their speed, whereas Icarus – who also detect the same neutrino beam – measure the spread in energy of the arriving neutrinos. They found that the neutrinos don't lose energy on their route. The problem of course is that they should do, if they were travelling faster than light. This is the equivalent of the sonic boom when something goes faster than sound.

"Usually we see this effect when particles go faster than light through transparent media like water, when light is considerably slowed down. It's called Cerenkov radiation. So these neutrinos should have been spraying out particles like electrons and photons in a similar way if they were going superluminal – and in the process would be losing energy. But they seemed to have kept the energy they started from, which rules out faster-than-light travel."

Matt Strassler, professor of theoretical physics at Rutgers University in New Jersey, said the Icarus results did not completely rule out faster-than-light neutrinos. "Cohen-Glashow and Icarus have shown that if Opera is correct, and Einstein's relativity must be modified, then that modification must also cleverly eliminate the Cerenkov-like radiation that would have affected both Opera and Icarus. That's a very tall order, to be sure; but until someone proves that no such modification is possible, we can't firmly conclude Opera is wrong," he said.