Moar on the superfast neutrinos

September 24, 2011 • 11:20 am

Dennis Overbye has a report on the faster-than-light neutrinos in today’s New York Times.  Aside from the dreadful leaden “lede” (“Once upon a time, the only thing that traveled faster than the speed of light was gossip.”*), it gives a bunch of detail not described in my previous post. Dario Autiero, team leader, gave a talk on the results (link is below) and seemed to imply that the results were pretty solid: neutrinos sent from Switzerland to Italy appeared to travel faster than light:

According to Dr. Autiero’s team, neutrinos emanating from a particle accelerator at CERN, outside Geneva, had raced to a cavern underneath Gran Sasso in Italy — a distance of 454 miles — about 60 nanoseconds faster than it would take a light beam. That amounts to a speed greater than light by about 25 parts in a million. “We cannot explain the observed effect in terms of systematic uncertainties,” Dr. Autiero told the physicists at CERN, the European organization for nuclear research. “Therefore, the measurement indicates a neutrino velocity higher than the speed of light.”

And, oh, the sweet litany of scientific doubt that accompanies such a finding (my emphasis):

“This is quite a shake-up,” said Alvaro de Rujula, a theorist at CERN. “The correct attitude is to ask oneself what went wrong.” And the assembled CERN physicists were only too happy to oblige, diving in, after Samuel C. C. Ting, an M.I.T. Nobelist in the audience, offered his congratulations for work “very carefully done.” They asked detailed questions about, among other things, how the scientists had measured the distance from CERN to Gran Sasso to what is claimed to be an accuracy of 20 centimeters, extending GPS measurements underground. Had they, for example taken into account the location of the Moon and tidal bulges in the Earth’s crust?

That reminds me of Feynman’s famous quotation about why science is like it is:

The first principle is that you must not fool yourself–and you are the easiest person to fool. So you have to be very careful about that. After you’ve not fooled yourself, it’s easy not to fool other scientists. You just have to be honest in a conventional way after that.

The article goes on to describe the experiment in detail (I haven’t checked the physics blogs, but I’m sure they do a good job, too), and reports that the purpose of the experiment was not to measure the speed of the neutrinos, but to see them change form in flight (there are three types of neutrinos):

Measuring the speed of the neutrinos was only a side ambition, explained Antonio Ereditato of the University of Bern, the head of the Opera collaboration. “Now it is becoming a main issue,” he said, adding, “we would like to see some tau neutrinos,” to appreciative laughter from the audience.

Oh, those wacky physicists! There was further criticism of the brouhaha and press-conferency nature of the announcement:

In the old days, when scientists sent around copies of journal articles and wrote letters to one another, the process of scrutiny of a controversial measurement could have happened quietly, but the Web has changed all that. Dr. Autiero’s talk at CERN and the appearance of a paper by the Opera group on the Internet Thursday night came at the end of a drumbeat of rumors and blog postings. One blog called it “Rumour of the Century.” Some physicists, inside and outside of CERN, were critical of this process, saying the laboratory was giving too much weight to a premature result by a group that was not even part of CERN. Nima Arkani-Hamed, a particle theorist at the Institute for Advanced Study in Princeton, said in an e-mail, “There was no need for a press release or indeed even for a scientific paper, till much more work was done. They claim that they wanted the community to scrutinize their result — well, they could have accomplished that by going around and giving talks about it.” Rolf-Dieter Heuer, director general of CERN, said in an e-mail from Spain, “I agreed to the seminar at CERN because it is the duty of a lab like CERN to give the collaboration the possibility to ask the community for scrutiny of their findings.”

Bells and whistles aside, we may be on the verge of a dramatic new era in physics, akin to Planck’s study of black-body radiation.  My guess is that the faster-than-light observation is still in error, but I’d be delighted to be proven wrong (see the cartoon below).

Two other items:

1.  Alert correspondent “Llwddythiw” found the webcast of the CERN talk. I haven’t yet listened to it, but here’s his report:

I came across this webcast from CERN.  It’s long, nearly 2 hours, of which roughly the second half is given over to Q&A.  I think it’s excellent, not only for the probing questions and good answers but simply as a clear model of the way in which the scientific investigation is being pursued

2.  xkcd didn’t lose any time producing a pretty funny cartoon about the new discovery:


*  This statement reminds me of an incident that happened when I was about twelve.  My dad, a career Army officer in the Finance Corps (that’s where they put the Jews in those days!), collaborated on a project involving the rapid destruction of American currency.  The idea was that, in those Cold War days, the Treasury should develop a way to rapidly destroy stocks of currency should the Russians invade, for the enemy could use our banknotes for their own nefarious purposes.  But you can’t simply burn a tight stack of bills; it’s like trying to burn a telephone book (remember them?).  Finally, a combination of chemicals and fire did the trick, reducing bills and coins to hard, gray lumps resembling cement.

The Washington Post wrote an article about it, and quoted my dad on how fast they’d managed to destroy currency: “‘The only faster way I know to get rid of money,’ said Coyne, ‘is to give it to my wife.'”  My mother, needless to say, wasn’t pleased.

61 thoughts on “Moar on the superfast neutrinos

  1. I’m no fan of science-by-press-release, but realistically a result like this is going to cause a lot of kefluffle prior to formal publication, anyway. And I think it is notable how these researchers handled the announcement of their findings versus the circus that was the “arsenic life” that NASA announced. In the neutrino case, the work was discussed at a CERN seminar, with lots of scientists asking questions, and with the authors being very circumspect as to the meaning of their findings. This was most definitely not the case at the NASA event, which was a straight-up press conference.

    1. Or a good public teaching tool that serves as a handy-dandy reference to deal with creationist/conspiracy theory whackjobs. Just point to this and see – that’s what an actual scientific argument looks like; nothing like “Expelled”.

    2. $100 says it will be neither. (Hey, I need the money.) For me there isn’t even anything to get excited about; there are so many sources of error to be picked at yet (and this alone will take a hell of a lot of time and experimentation) and the findings are so much at odds with what we currently know. For example, if it were true that the speed of a neutrino is higher by roughly 25/1,000,000 then the neutrino emissions from a supernova ~170,000 light years away would arrive about 4.25 years before the optical observation. What has actually been observed is that neutrinos show up a few hours before the optical observation (thanks to the fortuitous measurement of neutrinos from Supernova 1987a) which is about what the astrophysicists expect from their supernova models. Now we can suppose that the supernova models are wrong and that neutrinos and visible light are produced at the same time at the supernova – but OPERA’s results would be consistent with the neutrinos from SN1987a arriving 4.25 years before the optical observation. There are large errors in the estimates of the distance to stars, but they’re nowhere near large enough to support the OPERA observation. I wouldn’t be surprised if there are already people out there trying to find out if neutrino observations were also done anywhere up to 6 years before SN1987a which can demonstrate the absence of a neutrino source consistent with OPERA.

      So I’m expecting the verdict to be “nothing to see here”. Like many scientists, I’m expecting the reported result to simply be incorrect. (If there is enough evidence to show I’m wrong, then I’ll get excited.)

    3. It’s going to be a letdown. The theory is rock-solid. How can they say that the neutrinos arrived a few nanoseconds earlier than expected when they only measured the distance between the two points to an accuracy of only 20cm? It just doesn’t sound convincing.

      1. Do the math. At 3×10^8 m/s, a light-nanosecond works out to 30 cm. So 20 cm of positional uncertainty contributes less than one ns of uncertainty to the time discrepancy, which is around 60 ns.

  2. I had no idea that the man who kicked off the question session by roundly praising the experiment was Sam Ting of the J particle.

    They mentioned in the paper and in the seminar that similar results, a negative value of (v-c)/c, had been seen in the MINOS experiment at Fermilab in 2007, but the uncertainties in those measurements were considerably larger than for OPERA, and the results were not regarded as significant. One of the later questions was about the calibration of some piece of equipment (I don’t recall which), and it sounded as though the MINOS experiment had not calibrated it to the same level, although Autiero added that it would be quite easy to do so. I think this is exactly what’s going to happen at Fermilab.

      1. Actually, Sam did name it simply “J”.
        So you were correct the first time around!

        (I have been told that “J” had something to do with some sort of connection between a Chinese character and his name.)

        Burton Richter independently named it the “psi”.
        Eventually a compromise was achieved by merging the two names.

        1. Yes, that’s correct. I remember seeing Ting wearing a t-shirt with “J” on it. I wasn’t sure whether or not to “honour” Richter. The particle is usually referred to as the J/psi, so I followed that convention. The Chinese character for Ting’s name looks like a “J”. Richter originally wanted to call the particle the SP because it turned up in the SPEAR detector at SLAC.

    1. In the NYT article, Jenny Thomas of MINOS says they should have more accurate measurements within six months. If CERN’s results stand up to scrutiny until then we may see the seal of approval.

      I would still bet against it, despite the first MINOS result itself being worthy of the raising of at least one eyebrow.

  3. In 1989 a supernova erupted in the Large Magellanic Cloud. The Kamiokande neutrino detector in Japan, picked up a burst of neutrinos, which were thought to have come from the core collapse of the star. The LMC is about 160,000Ly away, so a speed excess of 25ppm would mean that the neutrinos would have arrived about 4 years early! This doesn’t seem to tie up with the Gran Sasso data …..


    1. I’m not an expert by any stretch, but as far as I’m aware there’s no law that says that all neutrinos have to travel at the same superluminal speed. The supernova neutrinos were presumably produced by a different process and therefore had different kinetic energy, ergo different speed, than the Gran Sasso neutrinos. For high enough energy, the speed becomes infinitesimally different from lightspeed, even for tachyons (if neutrinos are indeed tachyons).

  4. Reminds me of the kerfuffle over cold fusion. Might still be something in the idea of faster than light – isn’t the idea of the expansion of the universe just after the big bang based on that? But most, I expect, will hang on to their skepticism for awhile yet.

    1. That was QUITE a different case!
      Nobody is going to see his/her career being cut short over THIS case!
      The cold fusion dudes left town in tar and feathers!

      1. How so? Seems to me, admittedly from the few bits and pieces I’ve read, that there are some questions on how accurately the distance was measured.

        Though I’ll agree with you about the ministrations of Dr. Tar and Professor Feathers. But that, and maybe this case as well, does indicate wishful thinking can manifest itself even in those who should be most on guard about it – particularly in light of Feynman’s aphroism on the point.

        1. How so?

          Fleischmann and Pons held press releases and press conferences claiming to have seen cold fusion, BEFORE submitting their findings to the scientific community for peer review.

          The neutrino guys turned to their colleagues, basically saying: “We found something SO weird, it’s almost as if some neutrinos went faster than light, but we can’t find the error, please help us find the error!”

          QUITE a different approach!

      1. It took me a while, but finally it dawned on me (from the Bad Astronomer, IIRC) that astronomers measure dates from light as observed (arrival date), not observed light (transmitted date). The reason is that a) it is simpler b) the physics needs to be riddled in the local frame anyway.

        1. Not to mention that the estimates of distance may change in the future and cause a huge mess if we were to attempt to use the time at origin. We know when an observation was made on earth to some incredible accuracy and precision; any estimates of the actual timing of an event observed at earth is dependent on our estimate of distance to the object.

  5. This is qualitatively different from Planck’s work, in the sense that the classical view of black body radiation had a much more serious drawback: it didn’t agree with the experimental curve at all: the experimental curve for energy density went to 0 at low density, the classical curve went to infinity.

    On the other hand, Lorentz invariance has borne itself out very very well in experiments so far.

  6. Hydrogen atom 1: I think I lost an electron!!

    Hydrogen atom 2: Are you sure?

    Hydrogen atom 1: Yeah, I’m positive!

    What’s really sad, though, is that the neutrino jokes didn’t come out last week.

    Neutrino. Who’s there? Knock knock.

    Like falling off a log or, more flatly stated, a log-log.

  7. On watching the seminar and reading about the experiment, I’m reminded of a passage in one of my favourite science fiction stories, The Black Cloud, by Fred Hoyle.

    In the second chapter, a professor of Astronomy at Cambridge, Chris Kingsley, attends a meeting of amateur astronomers at which there is a presentation about discrepancies in the positions of Jupiter and Saturn. Kingsley is confident that the amateur astronomer who made the observations has messed it up. The amateur, Mr. Green, makes his presentation and the audience, in which there are also many professional astronomers, is waiting for Kingsley to pounce on him. Mr. Green finishes and:

    “Kingsley never heard the loud applause offered to Mr. Green as a reward for his address, for Kingsley was choking with rage. He had come up to the meeting expecting to be told of discrepancies amounting to no more than a few tenths of a second at most. These he could have attributed to inaccurate, incompetent measurement. Or there might have been a subtle mistake of a statistical nature. But the figures that Mr. Green had written up on the board were preposterous, fantastic, so large that a blind man could have seen them, so large that Mr George Green must have made some outrageous blunder.”

    It’s a great story. Suffice it to say, George Green had not made an error. There was something odd going on with Jupiter and Saturn.

    1. Meh. The anti-evolutionist deist Hoyle was already headed into crackpot obscurity when he wrote that defense for an eternal steady state universe which was his solution to “no evolution, so god”. (With infinite time his junkyard _would_ have worked – he thought. The rest was supposed to be through transpermia.)

      It is a bad reference on science, especially on WEIT.

      The context destroys my appreciation of it, the ETI cloud was nifty.

      1. I’ll see your “meh” and raise you a “feh”. Why is it a “bad reference on science, especially on WEIT” to quote from a fictional novel, even if the author had separately some wacky ideas about science, or did I misunderstand your comment?

  8. “… how the scientists had measured the distance from CERN to Gran Sasso to what is claimed to be an accuracy of 20 centimeters, extending GPS measurements underground.”

    It’s easy to believe that a mistake was made here. GPS is based on the WGS-84 ellipsoid mathematical approximation of the Earth. The more recent IERS-2003 ellipsoid is about 0.0000127% smaller (a much larger difference than 1 in 25 million), which would lead to an overestimate of the distance traveled. Plus, either way it’s just an approximation, not accurate to 1 in 25 million.

    1. That was my idea, as I wrote on yesterday’s thread.

      _And_ incidentally the ~ 20 m extra distance when using the IFRT2000 geodesic distance over ~ 730 km Earth surface gives exactly the discrepancy – one would think the neutrinos arrives ~ 60 ns early.

      The difference is buried in a preparatory paper where they go from a geodesic distance 3D system to an “OPERA” 3D system. They don’t make any conversion explicit, so it is difficult to check instantly.

      But that is what we have peer criticism for.

    2. Oops, sorry. My idea was _tied_ to the geoid, not that it was erroneous of itself. That could be the actual problem, since the error you mention is of the correct magnitude!

      1. If I remember correctly, you can submit questions about the experiment directly to CERN. I think your question would be an interesting one for them to consider.

  9. I saw a commercial for a news report that was big and controversial sounding saying, “Was Einstein WRONG?! Is E=mc^2 wrong?”

    I immediately thought of the headlines that you could have found when Einstein presented his theories. “Was Newton WRONG?! Is F=ma wrong?”

    The answers to both of those are no, not with the data they had, and it still works in certain conditions.

    There was a comic, I think from Saturday Morning Breakfast Cereal, that said if you can answer your science headline with a simple “no” then don’t publish it.

    America just seems to really like thinking that science is actually broken. Can’t really put my finger on why. It seems like people just want to say see, those scientists aren’t really all that smart.

  10. They could calibrate the distance by generating and sending lower energy neutrinos of the type seen in the 1987 supernova. We have good astronomical evidence from the supernova showing that those neutrinos do not travel faster than the speed of light. If these guys find those low-energy neutrinos to have a speed greater than c by the same factor as their high energy neutrinos, they will have proven that their distance measurement is wrong and that the high energy neutrinos travel at or below c.

    1. If by “sophisticated” you mean point to whatever is true and say “see! that proves our point”, then no. This won’t be a hiccup at all. Hell, it’ll solve that pesky problem of whether god is trapped in time, or transcends it. He transcends it, you see, because he moves faster than light, just like natural particles do, and thus has access to all information simultaneously. QED.

      They’ll figure something out either way this comes down. What would be interesting to see is a ‘sophisticated’ theologian saying in advance what their study of their god determines will be the outcome, and why the other option can’t happen.

      We’ll be waiting a long time to see that I suspect. The ‘sophisticated’ ones have learned not to say anything concrete or even sensible. History has shown that provides the rest of the world the necessary tools to prove them wrong.

  11. Something must have gone right in conveying this information to the public because every news story I’ve seen on this has been surprisingly non-sensationalist. They have all included the disclaimer that in cases like this it is probably a mistake, and the rules of relativity are very well supported by evidence.

  12. I’m hoping they haven’t overturned relativity, just after I noticed how it gives rise to the strong force. It was quite a beautiful surprise. I was only expecting to explain the origin of the magnetic force, as a direct consequence of the Thomas precession. It appears to be an anti-Coriolis force of the Thomas precession. There is thus an anti-centrifugal force too. It should overcome Coulomb repulsion at about the nucleonic scale.

    Sorry to go OT, but it would be nice if anyone could get interested in it. It’s not easy getting attention being only an amateur physicist. I can do things no physicist could get a grant for, though. Link to the paper at my blog (/website).

  13. That’s an awesome story about your dad. I bet he knew he’d be in trouble when he got home, but it was too good of a set-up to pass up.

  14. Bemoaning the loss of the past way of processing new findings and hinting at a moral superiority just seems, well a self-serving, moral/value judgement.

    Whether this finding is true of not seems less interesting than the evolution in the scientific method based on the new tech – that’s always kool.

  15. I’ll go on record here and say that it’s bunk. I’m not a physicist but I was also ultra-skeptical of the claims of “cold fusion” by Pons and Fleishmann when they were announced. This story is very much like that one though the authors here appear to admit that their results are questionable.

    So, a neutrino has been measured at 1.000025 light speed? Extraordinary claims require extraordinary evidence. That said, no one saw dark matter or energy coming (pun intended) to physics/cosmology and look where we are now.

    1. Skepticism is certainly warranted, but tarring this work with the cold-fusion brush is not. In fact the contrast between the two cases could not be starker.

      In the cold-fusion case, two chemists working outside their field, on a poorly-controlled experiment, made exaggerated claims about their results directly to the press, without first submitting their work to critical scrutiny by the physics community.

      In this case, we have a team of skilled experimentalists working within their specialty, with rigorous documentation of every aspect of their work, who have not hesitated to call in additional specialists to help validate those aspects outside their immediate expertise (such as geodesy). They described their results to a panel of scientific peers as a timing discrepancy, for which they declined to offer any theoretical or phenomenological interpretation. They specifically did not say the neutrinos had traveled faster than light; they said they had some numbers that didn’t add up the way they expected, but after much checking were unable to find an error in their math. They’re not offering an explanation; they’re looking for one. Big difference.

  16. Here’s the great thing about this kind of argument and disagreement — data will tell us, or not.

    Ideology has no influence, beliefs have no influence and don’t matter. It’s a simple matter of facts, as decided by a group of trained observers of this kind of data.

    Real simple.

  17. The theoretical astrophysicist & excellent Starts With A Bang! blogger Ethan Siegel will be talking tomorrow night (Friday US / early Saturday UK’n’Europe) with KGW news anchor Steph Stricklen on Live@7 about…

    neutrino detection, the 1987 supernova, and what scientists are looking for as they go over the OPERA data. Listeners can participate in the live chat.

    7PM, Fri Pacific/ 9PM, Fri Central/ 10PM, Fri Eastern/ 3AM, Sat GMT

    For more info & how to tune in on the net go HERE

Leave a Reply