Excellent summary of FTL neutrino observations


The New York Times has a very well done summary of what’s going. (They even include mention of the comic that Paul linked to here yesterday. Perhaps they’re reading your stuff Paul…)

The article describes the skepticism of the international physics community as it was seen during the press conference to formally announce the results yesterday:

“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?

The recent history of physics and astronomy is strewn with reports of suspicious data bumps that might be new particles or new planets and — if true — could change the way we think about the world, but then disappear with more data or critical scrutiny. Most physicists think the same will happen with this finding. The prevailing attitude was perhaps illustrated best by an XKCD cartoon, in which a character explains his intention to get rich betting against the new discovery.

Neutrinos are still a cosmic mystery. They are among the weirdest denizens of the weird quantum subatomic world. Not only are they virtually invisible and able to sail through walls and planets like wind through a screen door, but they are shape-shifters. They come in three varieties and can morph from one form to another as they travel along, an effect Dr. Autiero and his colleagues were trying to observe.”

More here.

I like the last ‘graph particularly. My gut says, that if this is true, there’s more to learn about neutrinos. They were first imagined by Fermi as a simple mechanism to preserve conservation laws when particles decay. Gary Steigman won the gravity prize back in the day (when I was at Bartol with him) for suggesting that they might have mass enough to close the Universe. Now we know they change flavor in flight. Weird little things.

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Episcopal bishop, dad, astronomer, erstwhile dancer...


  1. Sean Barnes says

    I read a good statement on this subject on an AP Physics web site. David Derbes teaches at the University of Chicago Laboratory Schools. Here is his post:

    Subject: Re: LHC speed of light broken or error?
    From: David Derbes
    Date: Fri, 23 Sep 2011 11:19:16 -0500

    It’s an error.

    My guess is that the error stems from an inaccurate measurement of the distance traveled.

    Here is why I believe it is an error.

    On February 23, 1987, a supernova (1987A) was observed. Subsequent to the observation, it was realized that a neutrino experiment at Tokyo (Kamiokande II) might have picked up some neutrinos from the supernova. Typically in a year they got on the order of five to eight. Three hours before optical observation, Kamiokande II got 11 events in 13 seconds! (Other neutrino experiments, though not as sensitive, also picked up a flurry of events.)

    The star that blew up is 168,000 light years away. Light needed 168,000 years to get here. The neutrinos got here three hours early, which is expected for two reasons. One, the nuclear reactions producing the neutrinos precede the optical burst, and two, the neutrinos have an easier time fighting their way out of the core than photons do. This three hours was pretty much in line with theoretical understanding. (Incidentally, this result put an upper limit of 16 eV on the mass-energy of the electron neutrino.)

    Now the CERN experiment says that the neutrinos shaved 60 nanoseconds off of a trip that would have taken light 2.43 microseconds. That is a 2.47 percent difference.

    If this difference were real, the Kamiokande II neutrinos would have shown up not 3 hours early, but 4,149 years earlier, assuming the same 2.47 percent. We would never have seen this burst nearly coincident with the photons.

    There’s an error somewhere. It’s good of CERN to put this out there; brave, too. They’re going to catch a lot of flack for it, but it’s the right thing to do.

    David Derbes
    U of Chicago Laboratory Schools

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