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Are neutrinos moving faster than the speed of light?

Was Einstein wrong? That's what physicists are wondering now that new data from the CERN facility in Switzerland appears to show that neutrinos are travelling faster than the speed of light.

Was Einstein wrong? That's what physicists are wondering now that new data from the CERN facility in Switzerland appears to show that neutrinos are travelling faster than the speed of light. While the findings of this project still have to be verified, it could mean a major upset for the theory of relativity. The Burnaby NOW's Jennifer Moreau spoke with SFU physicist Dugan O'Neil to discuss the significance of this physics experiment, dubbed OPERA.

Q. Can you introduce yourself?

A. I am an associate professor of physics at SFU. I am not personally involved in the OPERA project. I am a particle physicist who works on the ATLAS project, which is located at CERN. The OPERA experiment is a particle physics experiment, which is also associated with CERN. Their neutrino beams come from CERN.

Q. Tell me about these latest developments. What did scientists find?

A. Scientists at OPERA study the properties of particles known as neutrinos. The main goal of the experiment is not to find the speed of the neutrino. However, it is a measurement they decided to do with very high precision. Here is how it worked: A beam of neutrinos was produced at CERN, this beam passes 730 kilometres from CERN, in Geneva, Switzerland, to the Gran Sasso laboratory in Italy. The OPERA detector sees the neutrinos and makes measurements. In this case, they went through great effort to measure exactly where their lab is relative to the source of neutrinos. They know the distance within 20 centimetres over 730 km and have clocks synchronized to within about two billionths of a second. In addition to their particle physics expertise, they collaborated with both the Swiss and German metrology institutes to get such precise timing. They then measured how long it took the neutrinos to reach Gran Sasso and found that they arrived about 60 billionths of a second ahead of when light would have.

Q. What is a neutrino exactly?

A. A neutrino is a very unusual subatomic particle. It is not charged and has almost no mass. It can pass through very large amounts of matter without interacting. Right now, each of us has neutrinos streaming through our bodies, without effect. So, they are very difficult to detect, and we have no easy mechanism to directly manipulate them. However, people have built very clever detectors to be able to see neutrinos and measure their properties. We have decades of experience measuring neutrinos and know quite a lot about them. However, they remain mysterious and further exploration of neutrino properties is one of the hottest topics in particle physics currently.

Q How significant are these findings?

A. The findings still need verification. They have only been released today (Sept. 23) and will take some time to be verified by a second independent experiment. However, if this result is correct, it is very significant. The speed of light in a vacuum has been considered the universe's ultimate speed limit for more than 100 years now. Special relativity has been tested many times to very high precision and has passed every test with flying colours. If neutrinos travel faster than the speed of light, at the minimum it means we have to really rethink what neutrinos are. It could be much more profound than this though. The notion that nothing travels faster than light preserves cause and effect. If signals can be sent faster than light, it could create some real logical paradoxes related

to sending messages backwards in time. If special relativity is wrong, then many ideas would need re-thinking.

Q. Does this mean Einstein's theory of relativity is wrong?

A. It could mean this. It will take some more work to figure out exactly what it means. If this result is true, I can say for sure that it is an extremely important result in understanding our physical world. I cannot say for sure how it will alter our understanding.

Q. Everyone seemed to focus on finding the Higgs Boson, or the so-called

missing link in the standard model of physics. How do these new findings change the bigger picture?

A. People are still very focused on this. In fact, that is one of the things I focus on. This result would not change our immediate strategy for Higgs searches. However, it could lead people working on extensions to the Standard Model down a better path, and cause some revisions in the theory in the future.

Q.What happens next?

A. The most important things now are the community should examine the existing paper, which came out just this morning, very carefully to look for problems, and the facilities with the capability to reproduce the result - there are similar facilities in Japan and the U.S. - should try to reproduce or refute it.

Q. Is there anything else you want to add?

A. The OPERA experiment is very confident in their result. However, a result of this magnitude really needs to be verified by an independent experiment before we are all convinced.

For more on this story, see Jennifer Moreau's blog, Community Conversations, at www.burnabynow.com.