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Particles from space?

  1. Jan 25, 2010 #1
    Particles from space????

    Which particles arrive from space and pass through the earth????

    How is this possible?

    Are they called neutrinos?
     
  2. jcsd
  3. Jan 25, 2010 #2

    berkeman

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    Re: Particles from space????

    Do a quick search on Neutrino at www.wikipedia.org for an introductory article.

    If you ever get a chance to watch this episode of Nova, you will probably enjoy it:

    http://www.pbs.org/wgbh/nova/neutrino/

    .
     
    Last edited: Jan 25, 2010
  4. Jan 25, 2010 #3
    Re: Particles from space????

    is it because they have little mass and no charge? So this means they would have limited interaction with heavier charged matter?
     
  5. Jan 25, 2010 #4

    berkeman

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    Re: Particles from space????

    Is that what the wiki article says? Certainly no charge would be a factor.
     
  6. Jan 25, 2010 #5
    Re: Particles from space????

    it says that they are electrically neutral and that they travel at the speed of light.

    i dont really understand what it means about "neutrinos travelling through matter undergo a process analogous to light traveling through a transparent material"
     
  7. Jan 25, 2010 #6

    berkeman

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    Re: Particles from space????

    They travel close to the speed of light, not at it. Anything with non-zero rest mass cannot make it up to the speed of light.

    The "miniscule" mass and charge neutrality probably are the main contributors to the very small reaction cross-section of neutrinos. You might do some reading about nucleear reactrion cross-sections to see if they discuss the neutrino.
     
  8. Jan 25, 2010 #7

    Astronuc

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    Re: Particles from space????

    Neutrinos interact with the nuclei, or more particularly the nucleons, in matter via the weak force. Consider the size or volume of the nucleus compared to the size of the atom. Ordinary matter is rather transparent to neutrinos.
     
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