Whoops! Faster-than-light neutrinos don’t exist after all

I’ve been informed by Matthew Cobb of this new piece in ScienceExpress, reporting that the OPERA researchers working at CERN made a mistake.  Those neutrinos didn’t move faster than the speed of light after all. And the mistake involved a loose cable! Well, that’s science biz. . .

I present their dispatch in toto:

It appears that the faster-than-light neutrino results, announced last September by the OPERA collaboration in Italy, was due to a mistake after all. A bad connection between a GPS unit and a computer may be to blame.

Physicists had detected neutrinos travelling from the CERN laboratory in Geneva to the Gran Sasso laboratory near L’Aquila that appeared to make the trip in about 60 nanoseconds less than light speed. Many other physicists suspected that the result was due to some kind of error, given that it seems at odds with Einstein’s special theory of relativity, which says nothing can travel faster than the speed of light. That theory has been vindicated by many experiments over the decades.

According to sources familiar with the experiment, the 60 nanoseconds discrepancy appears to come from a bad connection between a fiber optic cable that connects to the GPS receiver used to correct the timing of the neutrinos’ flight and an electronic card in a computer. After tightening the connection and then measuring the time it takes data to travel the length of the fiber, researchers found that the data arrive 60 nanoseconds earlier than assumed. Since this time is subtracted from the overall time of flight, it appears to explain the early arrival of the neutrinos. New data, however, will be needed to confirm this hypothesis.


  1. Nicolas Perrault
    Posted February 22, 2012 at 1:22 pm | Permalink

    Victor Stenger seems vindicated. Cold fusion comes to mind.

    • Jer
      Posted February 22, 2012 at 1:58 pm | Permalink

      Except that the cold fusion guys sensationalize their results while never opening up their research for public inspection, while the OPERA guys opened up theirs practically begging people to tell them where they were making a mistake because they couldn’t find it.

      So … not really like cold fusion much at all really. More like Science! (with a capital letter and an exclamation point and spoken in the voice of Doc Brown.)

      • Posted February 22, 2012 at 2:26 pm | Permalink

        Great Scott, Jer!


      • Hamilton Jacobi
        Posted February 22, 2012 at 7:30 pm | Permalink

        This is the proper way to say “Science!”:

        • Nicolas Perrault
          Posted February 22, 2012 at 9:29 pm | Permalink

          I agree!

          • Christopher Booth
            Posted February 23, 2012 at 11:32 pm | Permalink

            I agree!

            Hooray for Science!

            Science made the error, called attention to the error, sought out the explanation, found the error, admitted the error! Hooray for all involved! Integrity, honesty, patient laborious retracing…and they found the problem. Science is better for the experiment, better for the error, and better yet for the correction.

            Once again, Hooray for all involved!

      • J
        Posted February 23, 2012 at 4:44 am | Permalink

        Well said!

  2. Claimthehighground
    Posted February 22, 2012 at 1:27 pm | Permalink

    Damn, and I already set up a new religion of neutrinoism. Well, back to the drawing board.

    • MadScientist
      Posted February 22, 2012 at 2:03 pm | Permalink

      You can’t let facts get in the way of religion.

      • Sigh
        Posted February 22, 2012 at 2:25 pm | Permalink

        http://www.youtube.com/watch?v=9jKszduiK8E&feature=related Time travel research, because wearing funny hats invalidates facts.

      • truthspeaker
        Posted February 22, 2012 at 2:25 pm | Permalink

        Yeah, just say that the story of neutrinos traveling faster than light is a metaphor and was never intended to be taken literally.

        • Sigh
          Posted February 22, 2012 at 2:36 pm | Permalink

          Build a huge spaceship and tell everyone you guys are going to zoom to the Jurassic, sort of like other religious groups gather for the rapture.

          • Posted February 22, 2012 at 2:44 pm | Permalink

            Gathering for the raptor, perhaps?


            • Circe
              Posted February 22, 2012 at 6:14 pm | Permalink

              I hereby give you the Pun-Star of the day.

              • Posted February 23, 2012 at 1:08 am | Permalink

                Why, thank you!


  3. ZenDruid
    Posted February 22, 2012 at 1:29 pm | Permalink

    60 nanoseconds translates to less than 20 meters. Since there is no photon path to calibrate against, I’ve been assuming that the distance between LHC and OPERA was not precisely defined.

    • Gregory Kusnick
      Posted February 22, 2012 at 5:51 pm | Permalink

      Actually they had a small army of high-tech surveyors whose job was to define the distance to a precision of something like a few centimeters (as I recall). That’s what the sophisticated GPS equipment was for. It’s all laid out in their original report.

      However, as we are now reminded, precision and accuracy are not the same thing.

  4. Posted February 22, 2012 at 1:33 pm | Permalink

    It’s interesting to me how the English used in this dispatch is *very* good, but not quite perfect. I would guess that a very skilled non-native speaker wrote it.

    • Steve Bowen
      Posted February 22, 2012 at 2:13 pm | Permalink

      The fact that it’s anywhere near grammatically correct rules it out as British or American. But what’s your point?

      • NewEnglandBob
        Posted February 22, 2012 at 2:17 pm | Permalink


    • Chris
      Posted February 23, 2012 at 6:14 am | Permalink

      Yes, as an explanation it’s prety obscure, and seeing as its whole point is to explain – which means explain *clearly*, it fails.

  5. Tulse
    Posted February 22, 2012 at 1:44 pm | Permalink

    Science — it works.

  6. Marella
    Posted February 22, 2012 at 1:48 pm | Permalink

    Well that’s not surprising. A loose cable, we can all relate to that.

    • Posted February 22, 2012 at 1:59 pm | Permalink

      It is funny though, given how much time people spent trying to hunt down an error in much more esoteric parts of the timing configuration.

  7. Voltaire 2
    Posted February 22, 2012 at 1:49 pm | Permalink

    For want of a good connection, the warp drive was lost. For now.

    • Paeris
      Posted February 22, 2012 at 2:19 pm | Permalink

      If you manage to hunt down a gravity wave than Alcubierre drives and Einstein-rosen Bridges (consistent with General relativity) should still be possible.

      General relativity has means to survive even FTL objects. (Special does not… but well special relativity is only “aproximation” of general one without gravity and acceleration, much like Newton mechanics aproximates Special relativity at low speeds)

      • Torbjörn Larsson, OM
        Posted February 22, 2012 at 4:18 pm | Permalink

        Even if the effective theory of general relativity has seeming loopholes, there is a slew of problems in the rest of physics.

        Even in GR these problems pop up when you look at the actual constructions. Both these demanding more energy than the observable universe contains, exotic non-existent matter to shape the GR solutions and coping with paradoxes. For the Alcubierre drive, you need to have an object traveling ftl without the bubble to insert it and have it traveling ftl with the bubble. For the ER bridge, anything trying to enter the wormhole will collide with itself trying to exit.

        And the actual closure of GR is realized with its insertion into standard cosmology. (Which for example admits having a total energy for the universe, nothing you can’t get by GR alone.)

        There I hear ftl travel, say, by wormholes, will explode the universe. (Dunno the details there, though.)

    • Chris Booth
      Posted February 23, 2012 at 11:41 pm | Permalink

      Actually, it was so hugely improbable that there was faster-than-light travel, that Improbability Drive is still possible….


  8. Posted February 22, 2012 at 1:55 pm | Permalink

    Oh, well… not that I seriously thought the result was correct, but this is so… humdrum.


  9. Beau Quilter
    Posted February 22, 2012 at 1:56 pm | Permalink

    Here we see the important difference between scientists and clergymen. Scientist admit when they’re wrong, as soon as the evidence presents itself. Clergymen cling steadfastly to the same unsupported superstitions for thousands of years.

    • Voltaire 2
      Posted February 23, 2012 at 7:32 am | Permalink

      God doesn’t want us to go FTL because that is messing with his realm. How else can he be everywhere at once except with an utterly sophsiticated tachyon wormhole drive, right?

  10. Paeris
    Posted February 22, 2012 at 1:59 pm | Permalink

    However I get it problem is that timestamp assigned to when neutrino impacted detector arrived 60 nanoseconds LATE. to what was measured…

    So it slowed the actual speed of the beam didn´t it?

    I can not imagine “bad connection” to deliver the timestamp faster than good one.

    • Posted February 22, 2012 at 2:05 pm | Permalink

      If the GPS timing calibration pulse is delayed by a bad connection, then the neutrinos look like they’re arriving early.

      • Paeris
        Posted February 22, 2012 at 2:10 pm | Permalink

        Yeah that later arriving neutrion receives lower time than reality…

        You know that would actualy mean that… every single experiment they did last year was effectively invalidated?

        All energies are off… And well that they should have seen far sooner.

        • Posted February 22, 2012 at 3:06 pm | Permalink

          I’ve been trying to send them a message from here to back then. Won’t work for some reason.

          • Chris Booth
            Posted February 23, 2012 at 11:43 pm | Permalink

            OK, try now.

  11. MadScientist
    Posted February 22, 2012 at 2:00 pm | Permalink

    I’m inclined to say “Myth Busted”. I’ve said from the start that the most likely culprit is a problem with the timing – getting the required absolute timing is far from trivial. I’d still like to know more about the timing scheme and how they deal with the GPS specification of “<1ppm error" to obtain the absolute accuracy required for their specific task.

    I still have my suspicions though – why is a loose fiber causing a 60ns time delay?

    • Paeris
      Posted February 22, 2012 at 2:13 pm | Permalink

      They will have to check it anyway… Cern is in “winter sleep”.

      And well who knows when someone stumbled over that cable.

      • Occam
        Posted February 22, 2012 at 2:30 pm | Permalink

        Neutrino goes supraluminal.
        CERN guy stumbles over cable.

        • Voltaire 2
          Posted February 23, 2012 at 7:34 am | Permalink

          I know this will sound petty, but all the money and hype they spent on the LHC and CERN can’t handle a little winter?

          • Gregory Kusnick
            Posted February 23, 2012 at 8:03 am | Permalink

            You’re saying that because the equipment is expensive, they shouldn’t schedule any downtime for maintenance? That’s beyond petty; it’s nonsensical.

  12. Darth Dog
    Posted February 22, 2012 at 2:19 pm | Permalink

    “Hello. IT. Have you tried turning it off and back on again?”

    Well a loose cable is always the second guess.

  13. jonjermey
    Posted February 22, 2012 at 2:29 pm | Permalink

    As a devout Neutrinoist, my theory is that the fast neutrinos loosened the cable to cover their tracks after they were discovered.

    • Posted February 22, 2012 at 2:41 pm | Permalink

      Don’t you mean “before”?


    • Posted February 22, 2012 at 3:11 pm | Permalink

      My interpretation of the scripture is that the Gnutrino has put the ‘loose cable’ evidence in the faster than light record to trick us. Why? i don’t know; the Gnutrino’s ways are mysterious.

      • PB
        Posted February 22, 2012 at 5:22 pm | Permalink

        Yes. Notice that those confused by these findings are the scientists? Those Satan followers? G moves in mysterious ways ..


  14. Karl Withakay
    Posted February 22, 2012 at 2:31 pm | Permalink

    With the caveat that even this new information is provisional….

    It was hard not to be suspicious with such dramatic finding when the control was assumed. Since there was no pulse of light/photons to compare the speed of the neutrinos to, the well known value of c was used, but this assumed the speed of light in a vacuum as measured by their setup would have conformed to c precisely. By assuming the control, they could not rule out a measurement/timing error or potential effects to space time that would have also affected the measurement of the speed of light.

    • Bjarte Foshaug
      Posted February 22, 2012 at 3:06 pm | Permalink

      “With the caveat that even this new information is provisional….”

      Sean Carroll is making that very point over at Cosmic Variance:

      That’s what I love about science: Always wait for verification, even when the result is what everbody expected.

    • J
      Posted February 23, 2012 at 7:24 am | Permalink

      Pretty difficult to measure the speed of light through 730km of rock though 😉 There was no choice but to assume the control & take every step they could to measure everything both precisely & accurately, but yes, they couldn’t rule out an (as then) unfound timing error due to the equipment, which is why they asked for other experiments to try to replicate their findings.

      • Karl Withakay
        Posted February 23, 2012 at 8:17 am | Permalink

        Agreed about the solid rock. It might have also been a bit of a problem to dig a tunnel that long and pump out all the air too. 🙂

        It’s a reminder that although you sometimes have to assume your control, it’s important to remember that the control was assumed when you get highly unexpected results.

  15. Posted February 22, 2012 at 2:59 pm | Permalink

    The GPS equipment used in the experiment is made by a company called Septentrio. I have had problems with their equipment in the past.

    We bought one of their GPS scintillation receivers (a device which takes very rapid measurements, in order to study radio scintillation caused by the ionosphere). We took the device to Cape Verde, only to discover on arrival that something was rattling around inside the case. With their permission, we opened the thing up, and discovered that a small circuit board, which should have been soldered to the main circuit board, had broken off.

    The problem was obviously bad soldering. The circuit board’s pins weren’t bonded to the blobs of solder meant to hold them in place, leaving them free to slide out. The solder blobs were dull and crystalline, which is typical of bad soldering.

    We sent it back to them, and asked them to fix it. In return, we received a lengthy report, completely exonerating themselves, and accusing us of dropping the device. The accusation was based around a tiny little scratch, which on examining the device later on, I couldn’t even find.

    Eventually they fixed it. For a 5 minute soldering job, they decided to charge us 3000 euros.

    • Posted February 22, 2012 at 3:13 pm | Permalink

      I used to use their products too, until I started realizing that it appeared I was getting everywhere I wanted to be slightly ahead of schedule.

      • Chris Booth
        Posted February 23, 2012 at 11:49 pm | Permalink

        Justicar, did you ever use their products?


  16. Jimmy
    Posted February 22, 2012 at 3:14 pm | Permalink

    It is only a matter of time (no pun intended) before some wackaloon screams, “Cover-up! The gummint is trying to take away our gawd gibben right to FTL travel, time travel,and a Dukes of Hazzard retrospective.”

    • Chris Booth
      Posted February 23, 2012 at 11:51 pm | Permalink

      If you travel faster and faster, Daisy’s shorts get shorter and shorter (and you see she has a red shift).

  17. Torbjörn Larsson, OM
    Posted February 22, 2012 at 4:04 pm | Permalink

    A systematic error, as expected. A not crosschecked timing error, highly unexpected.

    I mean, it’s a complex setup, but surely they would have tried to calibrate the timing as much as they verified the distance!? This means we won’t even learn anything on the physics. (Well, after remeasuring we will.)


    A neutrino walks into a bar, and reconnects a loose cable. “We don’t serve slower-than-light neutrinos either,” said the bartender.

  18. R.W.
    Posted February 22, 2012 at 7:37 pm | Permalink

    I can already see the outline of Rabbi Moshe Averick’s next coulumn:

    If all it takes is a simple loose cable to lead so many qualified scientists astray, just think of how many other scientific “truths” must be based on work performed on as-yet-undetected faulty equipment.

  19. Diane G.
    Posted February 22, 2012 at 8:46 pm | Permalink


  20. Lotharloo
    Posted February 22, 2012 at 10:39 pm | Permalink

    Ethan is not very impressed by the cable solution either but he notes that there are already two experiments going on that will shine some light on this, one way or the other, whether OPERA find a fault with their tests or not.

    In Japan, they’re creating neutrinos at similarly high energies to the OPERA experiment, and sending them from Tokai to Kamioka, over a distance of 295 kilometers.
    We’re also, in the United States, sending a beam of neutrinos underground from Fermilab to Soudan Mine in Minnesota. The distance from Fermilab to Soudan Mine? An uncanny — wait for it — 732 kilometers.

  21. JesseS
    Posted February 23, 2012 at 12:16 am | Permalink

    It amazes me how many ‘skeptics’ are just accepting this one article, with no attribution or evidence WHATSOEVER, as truth.

    I’m not saying that the original faster-than-light experiment was right, I’m just saying MAYBE we should wait for something more susbstantial than this one weak report with no sources or attribution before calling OPERA this sloppy.

    We are supposed to be the ones who base our opinions on evidence, aren’t we?

    • Karl Withakay
      Posted February 23, 2012 at 10:28 am | Permalink

      Absolutely agreed. Though I am skeptical of the faster than light neutrino claim, I am also skeptical of this report as explanation of what supposedly went wrong. It may turn out to be true, but it seems nearly as incredible (in the literal meaning of that word) as the faster than light neutrinos.

      Apparently CERN has now confirmed that they are looking into the cable connections, which isn’t exactly the same thing as confirming the cable connection problem.

      As a side note, if neutrinos did travel faster than light, it would mean more than than Einstein was just a bit little wrong.

      According to special relativity, if they did travel faster than light, they should have not just arrived a little early, but before they left as they should have traveled backwards in time.

      • Gregory Kusnick
        Posted February 23, 2012 at 3:55 pm | Permalink

        Special relativity does not say that faster than light equals backwards in time. What it says is that different observers may disagree on the temporal sequence of events with spacelike separation. So what looks like “a little bit early” to one obsever might look like “before they left” to another observer. It does not follow that all observers will see them arriving before they left.

        • Karl Withakay
          Posted February 24, 2012 at 8:14 am | Permalink

          Question: Are you saying that FTL does not mean traveling back in time at all, or just that special relativity does not say FTL= backwards inn time?

          Also, I understand that there are other problems associated with FTL, such as increasing speed as energy decreases such that velocity approaches infinity as energy approaches zero.

          • Gregory Kusnick
            Posted February 24, 2012 at 5:03 pm | Permalink

            I’m saying that whether any given (spacelike) pair of events looks like traveling backwards in time depends on your frame of reference. Some observers will see A happen before B; others will see B happen before A. That’s what spacelike separation means.

            If you allow multiple hops, you can send a superluminal message from A to B, and then (in a different reference frame) from B to C, where C is in A’s past light cone. So in that case everyone will agree that the message arrived at C before it left A. But again, that’s not the same as saying that every FTL message automatically travels backward in time. It all depends on whose time you’re talking about.

  22. Karl Withakay
    Posted February 23, 2012 at 10:34 am | Permalink

    Either way, regardless of the eventual outcome, I can’t help but feel that an example of the triumph of the scientific process in action will be touted by some as an example of the fallibility of science, that science is often wrong, and that scientist don’t know anything. (ergo Jesus)

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