Tuesday, September 27, 2011

Faster than Light Neutrinos sure ain't Cold Fusion

The recent detection of faster-than-light neutrinos may turn out to be an error, but this experiment was no cold fusion fiasco.

[The OPERA neutrino detector on the left is leagues above the cold fusion cell on the right.]

Lots of people in the news, in university hallways, and even in cartoon form are urging caution against putting too much confidence in the measurement of neutrinos that travel faster than light. Many of them have suggested that the whole thing looks a lot like the ill-fated cold fusion announcement of 1989.

It's certainly true that the superfast neutrino experiment is one of the most surprising and unexpected announcements in the modern history of physics. And as Carl Sagan said, "Extraordinary claims require extraordinary evidence." While results from a single experiment probably fall a bit short of the extraordinary evidence level, I think it's misguided at the very least to cite cold fusion's sad story as a reason to be skeptical about this experiment.

Cold fusion and the recent neutrino experiments are superficially similar in that they each seemed to take catch the physics community off guard. Beyond that, there's not much the two have in common.

At least initially, cold fusion looked like a stunning technological development that had the potential to solve all the world's energy problems. The fast neutrino results, if true, are unlikely to have any practical applications for the foreseeable future, but they could make physicists rewrite some of the best established physics theories we've ever known. (It wasn't until people started finding flaws in cold fusion experiments that proponents began claiming to have discovered new physics.)

That is, from a fundamental physics point of view the fast neutrino results are actually much more extraordinary than the initial cold fusion claims. That suggests that the OPERA collaboration has an even higher bar to clear that the cold fusion "discoverers" faced.

The more important difference between the two cases, however, is the response of the scientific community once the researchers began discussing their experiments publicly. Following their press conference in 1989, it was clear to the vast majority of physicists just how shoddy an experiment Pons and Fleischmann had put together. There were countless suggestions for ways the experiment should have been done, as well as endless criticisms pointing out the many things they could have tried in order to double check their results. It was also clear that they lacked the expertise in the statistical analysis necessary to evaluate their own results.

The reaction at the seminar in CERN where the fast neutrino results were presented couldn't have been more different from the cold fusion fiasco. The OPERA collaboration appears to consist of a group of very sharp physicists who were eager to call in experts to handle particularly difficult portions of the experiment. Over the course of years, they repeatedly checked every source of error they could think of. They performed a double blind analysis that ensured that any biases they had would not affect the experimental statistics. No one at the seminar could come up with a single design flaw that the OPERA collaboration had yet to consider.

Of all the suggestions physicist at the seminar at CERN offered, the only one the collaboration hadn't already tried was building a duplicate set of detectors right next to the neutrino source to confirm that the distant set didn't suffer from some systematic design error. (I hope they will try it, but by the time build extra detectors other experiments may already have the data to back up or dismiss the fast neutrino results.)

It's true that most physicists remain skeptical of the notion that neutrinos move faster than light, but unlike cold fusion, which was built on a shoddy and rotten experimental foundation, it appears that the neutrino experimental design is as solid as the rocks beneath the Gran Sasso mountain.

It's not yet time to rewrite the physics texts, but there is clearly something very strange going on here. Either an extremely subtle experimental error is at work, or physics has suddenly gotten very interesting. It looks like we'll know for sure in a year or two. Personally, I'm not going to put all my chips on superfast neutrinos. Still, I sure hope we can one day look back on September 23, 2011 and think of it as the moment a new chapter in physics began. Thankfully, no matter what the outcome, it looks like it's not going to be a rerun of the tragic comedy that was cold fusion.

25 comments:

  1. This experiment should be looked at with open mind. Which theory to date, has not been improved?
    In very simple thinking - Sound waves have a fixed speed in air. Does that mean supersonic velocity is not possible through air? Obviously, it is, given sufficiently fast push.
    Samething can be applied to light (wave through space) and neutrino (resulting from collision). Some of them may have more speed than that of the colliding bodies.
    However any particles accelerated with magnetic force should not get faster than light because the pushing force field itself has a speed of light and it can not accelerate anything else to a speed that is faster than itself. i.e. as the particles approach speed of light, the magnetic field would cease to act on the particle.
    But with collision, faster than light particles are not only possible, they should be quite likely. However, such particles would eventually slow down as they pass through space to a terminal speed and that terminal speed may be same as speed of light. That is why if Neutrinos started faster than light from many light years away, they would stay faster than light only for some time and then attain a stable speed (of light). So, they do not really have to reach us years before as compared to the light from the same event, they may just reach few hours before.
    Thanks
    Krishan

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  2. The sound barrier was and is VERY different. Lots of things were know to travel faster than sound. Bullets, whips, rockets, planets, etc... Problem was to get a manned aircraft to travel faster than sound. Your watching too much Star Trek. Neutrinos if traveling faster than light would arrive on earth sooner than expected and they do not.

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  3. Until the CERN data has been independently verified, keeping an open mind would be a very good idea. And speaking of Star Trek, I wouldn't knock a show that has inspired many of today's physicists to love science in the first place.

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  4. I like the Star Trek idea mentioned about. What are the potential science-fiction-y implications? A comic on very subject: www.cinemabums.com

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  5. It's funny you should mention the "solid rocks of Gran Sasso". This was the exact area of Italy which suffered a massive earthquake in 2009. So the rocks aren't that solid here. I've read the team's paper, they don't have a firm enough grasp on the movements beneath the earth to say they've ruled it out.

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  6. Actually, BBBL67, I meant the mention of the rocks under Gran Sasso be a bit of a joke. There are certainly fissures and flaws in the rock, so even a rock solid foundation has potential for failure. If you watch the archived footage of the announcement of the neutrino results at CERN, however, you'll see that they mention the 2009 earthquake specifically. The relative separation of the source and detector changes suddenly by about 7 centimeters as a direct result of the quake. Check out slide 33 in the presentation available here http://cdsweb.cern.ch/record/1384486

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  7. Yup, I know they mentioned looking into the earthquake specifically, however that still doesn't mean they've taken it into account properly. A small 7cm displacement at the surface (where the GPS measurements are taken) may translate into much greater relative displacements several miles under the surface. Also when you take into account the Earth's natural curvature: small angular displacements could also be magnified.

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  8. I agree with most everything you said, but note that there was one other similarity between the superluminal neutrino findings and the cold fusion fiasco: In both cases there was a press conference to announce the findings before they had been verified. There are some in the scientific community who believe that such findings should be reviewed internally before going public.

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  9. I wouldn't have called the CERN seminar a press conference, it was an item like any other on the scientific program. No members of the press asked questions, and as far as I could tell there were no journalists in the room. The webcast was available to anyone who cared to surf on over, but that seems like the way the world is going these days. I imagine that all science conferences will be webcast within a few years.

    The cold fusion press conference, on the other hand, was a media circus.

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  10. I have one simple question: Are the neutrinos detected in San Grasso the same ones fired from collision? You're familiar with Newton's cradle...

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  11. Well, let's think about why we actually believe in Relativity. Primarily because the Eddington and Dyson light deflection measurements of 1919 created instant international hoopla and so many people liked the theory because of its mathematical beauty. Yes, the theory has held up under all(?) astronomical measurements of light made since. But how do astronomical measurements compare with the technology used at CERN and the accuracy of testing done in modern particle physics? Also GR has so far failed to be confirmed by the only modern high-tech class of experiments yet devised to check one of its subtler predictions, gravitational-waves.
    So maybe the physics community needs to suck it up and separate culture & precedent from experiment evidence.

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  12. Interesting question, Giovanni. I think it's safe to say that the particles detected at Gran Sasso are almost certainly the same neutrinos that left CERN. Neutrinos interact with matter very poorly, so they pass through the earth almost as though it isn't there. When they do interact with matter, they don't produce additional neutrinos, they usually produce their associated lepton (that is, electron neutrinos produce electrons, and muon neutrinos produce muons). Even if a neutrino led to a Newton's cradle-like string of other neutrinos, we wouldn't expect the interactions to speed them up. Instead you'd think they would go slower, if anything.

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  13. Anonymous, your criticism of GR seems a bit strong to me. After all, we use GR every day when we rely on GPS navigation, and even though gravitational waves haven't been found yet there is strong evidence that they exist and scientists expect to find them within the next few years when sensitive detectors come online.

    On the other hand, I think you're absolutely right, if the neutrino result is confirmed, that there will have to be a huge shift in thinking in the physics community. Similar shifts followed other breakthroughs like the Michelson-Morley measurement of the speed of light, detection of the cosmic microwave background, discovery of antimatter (i.e. positrons), Millikan's measurement of electron charge, Hubble's measurement of the expansion of the universe, etc.

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  14. A FRESH INTERPRETATION OF EINSTEIN’S MASS –ENERGY EQUIVALENCE supports superluminal neutrinos detected by OPERA.
    The recent detection of faster-than-light neutrinos CANNOT be an error. It is true that fellow scientists do not readily accept any “Extraordinary claims”. Probably many discoveries might have been buried for one reason or other. Science makes progress only when new claims are examined with optimism.

    My research paper claiming UV dominant optical emission from radioisotopes and XRF sources was rejected more than 13 times by leading Journals, since the claims are entirely new to X-ray physics, Nuclear Physics, Atomic Spectroscopy and Solar Physics. The research work lasted 21 years from the moment spectacularly high counts were detected by bare Photomultiplier from Rb XRF source to the publication of the research work in 2010: M A Padmanabha Rao, UV dominant optical emission newly detected from radioisotopes and XRF sources, Brazilian Journal of Physics, vol.40,no.1,March 2010. http://www.sbfisica.org.br/bjp/files/v40_38.pdf . Even after publication, none is ready to verify my detection of a new class of “Room temperature atomic spectra of solid radioisotopes and XRF sources” caused by “Bharat Radiation” by valence excitation. Anyhow, this happens with any revolutionary finding, so the neutrino researchers should not get disappointed.

    There have been similar situations where X-rays travelling faster than light. 1. Solar flare on April 21, 2002 has shown strong, localized bursts of high energy X-rays coming from the base of the flaring region well before the initial brightening in the EUV.
    http://www.gsfc.nasa.gov/topstory/20020605rhessi.html
    2. " the X-ray emissions of flares are followed, an hour or two later, by a pulse of extreme ultraviolet containing three times more energy than the initial X-ray burst".
    http://www.nature.com/news/2010/100724/full/news.2010.374.html “The observed delay in EUV emission to the X-rays has been attributed to X-rays traveling faster than EUV, against the traditional wisdom the X-rays and EUV travel at the same speed C". http://www.angelfire.com/sc3/1010/Solarfission.html

    The famous Einstein's mass--energy equivalence widely used for sub-atomic particles such as electron having a mass cannot be directly applied to neutrino with near-zero rest-mass or for gamma or X-ray having zero rest mass. Since gamma, X-ray or light photon are said to have no mass, all these photons can be assumed to have negligible but equal mass. When m is given a value 1, E equals to the square of light velocity C. On replacing C with V, which represents relative velocity, energy E of a gamma, X-ray or light photon equals to square of Velocity (V). If this modified formula is really true, 40 keV X-ray photon goes 100 times faster than 4 eV light photon. Similarly EUV photon can go faster than an infrared photon. Basically, this formula justifies X-rays travelling faster than a light photon from cosmic sources. Since neutrino’s near-zero rest-mass is somewhat close to X-ray’s zero rest mass neutrinos could travel faster than light. Since neutrino has near-zero rest-mass unlike X-ray the above formula needs further modification to precisely estimate its fastness over light.

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  15. I suggest you learn something about cold fusion. See, for example, the U.S. Defense Intelligence Agency report on cold fusion: "Technology Forecast: Worldwide Research on Low-Energy Nuclear Reactions Increasing and Gaining Acceptance" DIA-08-0911-003, 13 November 2009

    http://lenr-canr.org/acrobat/BarnhartBtechnology.pdf

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  16. Hi Jed,

    Here we go again. You and I have been down this road before, so I'll just reiterate that I believe that cold fusion is the epitome of junk science. There's no point in trying to convince me otherwise after 22 years of following this sad, sad field. Dressing it up as low energy nuclear reactions doesn't change a thing.

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  17. Hi Buzz Skyline,

    I submitted an idea to PTB about their GPS equipment used and how it tied with the OPERA equipment. Did the independent review consider the inconsistency of units? I remember a similar error occurring in a laboratory in California in 1999.

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  18. Hi DrAhcir,

    I'm afraid your question exceeds my knowledge of the experiment. You could probably get an answer by reading the paper they posted on the ArXiv. (http://arxiv.org/abs/1109.4897)

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  19. I might have an answer to why this happened. I finished reading the measurement of neutrinos you provided and I'm reviewing my calculations to make sure I didn't copy the wrong number but if I'm right it would account for the neutrino's seemingly evidence in arriving earlier than light. Bare with me a while I take a few days to review my calculations. I think the staff at CERN would be interested in hearing my results.

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  20. look at Table 1. final analsis
    calculate the flight time for yourself using
    1) the measured baseline distance:
    (731278.0 \pm 0.2) m (p.10)
    2) the speed of light: 299,792,458 m/sec

    then you get 24392808.4 ns.
    but the table 1 reads 2439280.9 ns.
    the difference is 72.5 ns deficit,
    which is well within the error range of the claimed deficit 60ns.

    conclusion? so far no tachyonic neutrinos presented by the OPERA paper arxiv1109.4897.

    what's the fuss in the media? that is the way house of cards are built.

    what the hell is the error from? no clue. is it an error? it seems. they should fix that thing first and start from there. did a graduate student use a single precision calculator (such as single precision Fortran)? may be. just guessing.

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  21. srhie620, you made an error.

    731,278/299,792,458 = 2439280.84, (not 24392808.4)

    The value in the table I believe you're talking about (on page 15) is not the measured flight time, but the time it would take for light to make the trip.

    As far as I can tell, they only quote the *difference* between the time of flight (TOF) for light and time of flight for neutrinos. I can't find an explicit statement of the TOF for neutrinos listed, but I gather it must be 2439220.2 ns or so.

    It seems like a pretty sloppy oversight that they don't explicitly include the neutrino TOF, but maybe I haven't looked hard enough.

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  22. Here it is with the commas inserted to make it clearer where the error was

    731,278/299,792,458 = 2,439,280.84 ns, (not 24,392,808.4 ns)

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  23. So, I've reviewed my calculations, nope I was wrong. I get the same results as the OPERA. I took the last few days to flight to CERN and talk to some of you there about this. They pointed out my errors, so this a mystery on my part. No idea of where the error could be, maybe the neutrino did travel faster than light. Maybe the neutrino didn't have any mass and was able to accelerate to the speed of light and some way able to travel faster by creating some kind of warp space or tunnel is a nano time-space which resulted in the early arrival. But this is a wild guess. Good luck from one scientist to another

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  24. I just read an article about explanations on these results. I have another random though, I know there is still a lot to learn about neutrinos (Tau, Muon, Electric). Could it be possible the origin of the neutrino is wrong? Could it be possible other neutrinos where formed from the collision at the same instant or close to the point of impact? Something like a chain reaction but simultaneously or close by a force not known. The collision origin result in a link of energy force or the electweak force to activate the creation of neutrinos close to the origin of impact resulting in a neutrino a fraction of a distant closer to the OPERA sensors in Italy resulting in a seemly early arrival but indeed it arrived at the expect time due to its closer proximity to the sensor but the origin of the neutrino was mistaken or assumed at the wrong coordinates? Could this be possible?

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