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Beaming Neutrinos Through Earth?

Posted by michael on from the death-ray dept.

TheMatt writes: "An article at PhysicsWeb talks about a proposed project by scientists at FermiLab. The project would involve sending a beam of neutrinos 10,000 km through the earth to a detector at SuperKamiokande. The hope is that passing through so much matter would alter the beam enough to better study CP (charge-parity) violation."

4 of 33 comments (clear)

  1. First impression by soulcuttr · · Score: 2, Interesting
    It sounded pretty far-fetched to me at first glance, but judging from the article...
    The SuperKamiokande site has already detected neutrinos from the KEK particle physics lab some 250 kilometres away, although the detector recently suffered an accident and is currently out of commission. There are also plans to send neutrino beams from the CERN particle physics lab in Geneva to the Gran Sasso underground lab 730 kilometres away in Italy, and from Fermilab near Chicago to the Soudan experiment, 710 kilometres away in Minnesota.

    I guess it's just an extension of experiments that are already going on. Will different densities affect how the neutrinos travel (making aiming a difficulty)? Or is that pretty much what they're depending on?

    And maybe a more importantly, what will happen if they miss? (insert wry grin here). I wouldn't hold my breath waiting to find out, though. The article says construction would have to begin by 2006, so there'll definitely be enough time for me to get out of the way.

    -Sou|cuttr
    1. Re:First impression by sigwinch · · Score: 3, Interesting
      The SuperKamiokande ... detector recently suffered an accident and is currently out of commission.
      "Accident" as in "half its photomultiplier tubes imploded". It will be some time before SuperK is back online.
      Will different densities affect how the neutrinos travel (making aiming a difficulty)?
      They ought to fly straight. (Not that that makes aiming easy!) The parameter of most interest is just the distance between the source and the detector. It is postulated that neutrinos can switch flavors in flight. The more distance they fly, the more chance they have of switching.
      --

      --
      Kuro5hin.org: where the good times never end. ;-)

    2. Re:First impression by TwP · · Score: 3, Interesting

      1^2=1; (-1)^2=1; 1^2=(-1)^2; 1=-1; 1=0

      Cute! However, the same logic can be applied to determine that 2=-2, 3=-3, 4=-4, ad infinitum, ad nauseum. In fact, using a third order mapping function you can show that three values (X1,X2,X3) are equivalent. Using a fourth order mapping function you can show that four values are equivalent. And so on . . .

      And now you see the problem of trying to apply a tautology to mapping functions that are not homeomorphic -- i.e. "one to one" and "onto".

      The function X^2=Y involves the loss of some information when mapping X to Y. There are two X values which will resolve to the same Y value. Therefore, the assertion that X1=X2 is correct since the inverse function is ambiguous as to which value of X was used to produce the given Y value. However, to assert that the value is zero you must impose the restriction on your mapping function that it is monotonically increasing or decresing -- i.e. that it is homeomorphic. X^2=Y is not.

      Still, very cute ;)

  2. Re:ping time by Anonymous Coward · · Score: 1, Interesting

    Cutting our latency by 1/3? That's a blanket marketing statement.

    Anywhere from 0 to (Pi-2)/Pi is the correct answer. I hope that's what they'll say in their publicity.