James Gillies, spokesman for the European Organization for Nuclear Research (CERN), speaks with RFE/RL correspondent Ron Synovitz about an experiment that has captured the attention of the world. If independently verified, the measurement of subatomic "neutrino" particles traveling faster than the speed of light would prove that one of the foundations of modern physics, Albert Einstein's Theory of General Relativity, was wrong.
RFE/RL: You've said that even the scientists collaborating on this research at the European Organization for Nuclear Research have found it hard to believe the results of their observations. Why is that?
Gillies: This kind of thing happens quite often in science. An experiment will measure something that looks unusual and the first thing you do there is say 'We don't really believe this.' Then you try to understand it in terms of your experimental apparatus, your analysis, your techniques and so on and so forth. Most of the time you do that and you find some rather mundane explanation and [the unexpected observation] goes away. But occasionally, you don't. That's what has happened in this case. The collaboration that has analyzed this data has tried very, very hard to understand it in terms of their apparatus and it hasn't gone away. So the next step is to put it up for scrutiny by the broader particle physics community, and that is actually what is happening right now.
RFE/RL: What if these findings are confirmed -- if other scientists independently verify that neutrino particles do travel faster than the speed of light. What impact would that have upon the field of physics?
Gillies: Relativity has withstood the test of time for nearly a century, and it's not because people haven't been testing it. People have. People have been measuring, doing experiments and making observations about relativity for a very long time -- and so far, nothing has shown that anything breaks this cosmic speed limit. So this would actually be at odds with quite a lot of what has gone before. That doesn't mean it is wrong. But there is a very strong feeling in the community that there must be a different explanation out there.
RFE/RL: In terms of scientific theory, can you explain why the experiment carried out by the scientists at CERN is so revolutionary to the field of physics?
Gillies: One of the big dilemmas arising from 20th-century physics is that so much of modern physics is based on two pillars that came up in the early part of the last century. One of them is relativity and the other is quantum mechanics. Relativity is a theory of gravity. There is no quantum theory of gravity.
So trying to reconcile these two things is one of the really [most important goals], if not the most important goal, for modern physics. If you start to find things like this, then maybe that would give you a way to reconcile the two basic pillars of modern physics. But first of all, we need to make sure whether this [observation] is real or not.
RFE/RL: Can you explain more about how the CERN experiments were conducted?
Gillies: Einstein's Theory of General Relativity says there is a cosmic speed limit and that is the speed of light -- [that] nothing can go faster than that. What this measurement [shows] is a measurement of the time it takes for a beam of neutrinos to fly from CERN -- 730 kilometers through the Earth -- to a particle detector underground at a place called Gran Sasso in Italy. It's about 732 kilometers away and the time of flight is about 2.4 [milli]seconds to do that. And what they appear to be measuring is that the neutrinos are arriving early. Only very slightly early -- it's a 20 part per million effect, but early nevertheless.
So if that is the case, then it really is an astonishing almost revolutionary result for physics -- which I think is exactly why we need to be extraordinarily cautious before we start jumping up and down and saying Einstein was wrong. That is what we are doing now. We are trying to really get to grips with this result, looking for independent measurements before we can make any definitive statements about what it really means.
RFE/RL: You've mentioned underground detectors being used in this experiment. Is the beam of neutrinos passing through any kind of tunnel system or other underground infrastructure that allows it to behave like a beam of light?
Gillies: It's not a beam of light. It's fundamental particles called neutrinos. These are tiny little particles that are very, very important in the way that the universe behaves because they are so ubiquitous. They are everywhere. They flood the universe. They are very tiny. They are very hard to detect. They interact very weakly. I mean, we are constantly bathed in a flux of neutrinos coming from space -- a large number from the sun -- most of which just go straight through the earth without interacting.
So we want to understand those particles and that's what these experiments are all about. Because they can go through the earth without interacting, it's quite easy for labs like Fermilab and CERN to generate beams of them and send them down into the earth. That's what we do. They go down through the earth and then they reemerge in these detectors, in our case, 732 kilometers away. So they're not in a tunnel. They actually are literally passing through the earth.
RFE/RL: In 2007, there were similar findings about neutrinos traveling faster than the speed of light discovered by researchers at the Chicago-based Fermilab. How is this new research different?
Gillies: That's a very interesting result too. Fermilab has a very similar experiment. They send a beam northwards to an underground detector about the same distance away. They did the same thing. They measured the time and they also saw that the neutrino seemed to be arriving slightly early. But their precision wasn't as high as this [CERN] experiment so they weren't able to make a strong statement on it. But what they are doing now is preparing to upgrade their equipment so they can make a more precise measurement of it. And we are all very much looking forward to seeing that."
RFE/RL: How long do you think it will be before independent follow up research can either verify or disprove that neturinos can travel faster than the speed of light?
Gillies: I would suspect that it is at least months and probably years. We send a lot of neutrinos through the earth, but because they interact very weakly you have to wait a long time. They interact weakly, but if you send a lot of them you will see some interaction. So I know that our experiments have been collecting data for three years. So this is based on three years worth of data collection. So I think it is going to be a while before we see any independent refutation or confirmation of this result.
RFE/RL: You've said that even the scientists collaborating on this research at the European Organization for Nuclear Research have found it hard to believe the results of their observations. Why is that?
Gillies: This kind of thing happens quite often in science. An experiment will measure something that looks unusual and the first thing you do there is say 'We don't really believe this.' Then you try to understand it in terms of your experimental apparatus, your analysis, your techniques and so on and so forth. Most of the time you do that and you find some rather mundane explanation and [the unexpected observation] goes away. But occasionally, you don't. That's what has happened in this case. The collaboration that has analyzed this data has tried very, very hard to understand it in terms of their apparatus and it hasn't gone away. So the next step is to put it up for scrutiny by the broader particle physics community, and that is actually what is happening right now.
RFE/RL: What if these findings are confirmed -- if other scientists independently verify that neutrino particles do travel faster than the speed of light. What impact would that have upon the field of physics?
Gillies: Relativity has withstood the test of time for nearly a century, and it's not because people haven't been testing it. People have. People have been measuring, doing experiments and making observations about relativity for a very long time -- and so far, nothing has shown that anything breaks this cosmic speed limit. So this would actually be at odds with quite a lot of what has gone before. That doesn't mean it is wrong. But there is a very strong feeling in the community that there must be a different explanation out there.
RFE/RL: In terms of scientific theory, can you explain why the experiment carried out by the scientists at CERN is so revolutionary to the field of physics?
Gillies: One of the big dilemmas arising from 20th-century physics is that so much of modern physics is based on two pillars that came up in the early part of the last century. One of them is relativity and the other is quantum mechanics. Relativity is a theory of gravity. There is no quantum theory of gravity.
So trying to reconcile these two things is one of the really [most important goals], if not the most important goal, for modern physics. If you start to find things like this, then maybe that would give you a way to reconcile the two basic pillars of modern physics. But first of all, we need to make sure whether this [observation] is real or not.
RFE/RL: Can you explain more about how the CERN experiments were conducted?
Gillies: Einstein's Theory of General Relativity says there is a cosmic speed limit and that is the speed of light -- [that] nothing can go faster than that. What this measurement [shows] is a measurement of the time it takes for a beam of neutrinos to fly from CERN -- 730 kilometers through the Earth -- to a particle detector underground at a place called Gran Sasso in Italy. It's about 732 kilometers away and the time of flight is about 2.4 [milli]seconds to do that. And what they appear to be measuring is that the neutrinos are arriving early. Only very slightly early -- it's a 20 part per million effect, but early nevertheless.
So if that is the case, then it really is an astonishing almost revolutionary result for physics -- which I think is exactly why we need to be extraordinarily cautious before we start jumping up and down and saying Einstein was wrong. That is what we are doing now. We are trying to really get to grips with this result, looking for independent measurements before we can make any definitive statements about what it really means.
RFE/RL: You've mentioned underground detectors being used in this experiment. Is the beam of neutrinos passing through any kind of tunnel system or other underground infrastructure that allows it to behave like a beam of light?
Gillies: It's not a beam of light. It's fundamental particles called neutrinos. These are tiny little particles that are very, very important in the way that the universe behaves because they are so ubiquitous. They are everywhere. They flood the universe. They are very tiny. They are very hard to detect. They interact very weakly. I mean, we are constantly bathed in a flux of neutrinos coming from space -- a large number from the sun -- most of which just go straight through the earth without interacting.
So we want to understand those particles and that's what these experiments are all about. Because they can go through the earth without interacting, it's quite easy for labs like Fermilab and CERN to generate beams of them and send them down into the earth. That's what we do. They go down through the earth and then they reemerge in these detectors, in our case, 732 kilometers away. So they're not in a tunnel. They actually are literally passing through the earth.
RFE/RL: In 2007, there were similar findings about neutrinos traveling faster than the speed of light discovered by researchers at the Chicago-based Fermilab. How is this new research different?
Gillies: That's a very interesting result too. Fermilab has a very similar experiment. They send a beam northwards to an underground detector about the same distance away. They did the same thing. They measured the time and they also saw that the neutrino seemed to be arriving slightly early. But their precision wasn't as high as this [CERN] experiment so they weren't able to make a strong statement on it. But what they are doing now is preparing to upgrade their equipment so they can make a more precise measurement of it. And we are all very much looking forward to seeing that."
RFE/RL: How long do you think it will be before independent follow up research can either verify or disprove that neturinos can travel faster than the speed of light?
Gillies: I would suspect that it is at least months and probably years. We send a lot of neutrinos through the earth, but because they interact very weakly you have to wait a long time. They interact weakly, but if you send a lot of them you will see some interaction. So I know that our experiments have been collecting data for three years. So this is based on three years worth of data collection. So I think it is going to be a while before we see any independent refutation or confirmation of this result.
