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Absorption of Solar Neutrinos

  1. Apr 28, 2010 #1
    Hi, I'm trying to find out the total number of solar neutrinos that interact with the human body per second or per lifetime. I know we are exposed to many, most which pass straight through us, but I'm interested to know how neutrinos interact with matter.

  2. jcsd
  3. Apr 29, 2010 #2
    why do you want to know? or rather, how MUCH do you want to know? if you want to know how they interact with matter from a quantum field theory approach I/we can guide you to resources.

    I think it is 1 or so ..
  4. Apr 30, 2010 #3
    To my knowledge, there has never been a serious study on solar neutrons interacting with human bodies. Nor a present need for such a study.
    They just don't affect biological organisms to any known significant degree at all.

    A "neutron bomb", on the other hand, can cause severe biological damage.
  5. Apr 30, 2010 #4


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    He's asking about neutrinos, not neutrons.

    The OP can find information about calculating rough estimates of interaction rates here:

    Neutrino cross section (Hyperphysics)
    Last edited: Apr 30, 2010
  6. Apr 30, 2010 #5

    George Jones

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    Coincidentally, I just happened to read the answer to this a couple of days ago.
    Yup. From the second edition of Introduction to Elementary Particles by David Griffiths:

    "John Bahvall, who was responsible for most of the calculations of solar neutrino abundances, like to say that 100 billion neutrinos pass through your thumbnail every second; and yet they are so ethereal that you can look forward to only one or two neutrino-induced reactions in your body during your entire lifetime."
  7. Apr 30, 2010 #6
    HOLY CRAP, that's amazing. Would neutrinos go right through very dense objects like neutron stars? Or would they simple get sucked in by its strong gravity?
  8. Apr 30, 2010 #7
    gravity can't bound them, but you can do an order of estimation, scale the mean-length for a neutrino in lead, divide with the density of neutron star, the result is order of meters... in lead.. light years
  9. Jun 16, 2010 #8
    Neutrinos don't interact with matter, that's why they pass through objects such as the human body. It takes 100,000 years for neutrinos to travel from the sun's core to it's surface, and only 8 minutes to travel from the sun's surface to earth. It's estimated that 50 trillion neutrinos pass through the human body per second.
  10. Jun 16, 2010 #9

    Vanadium 50

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    That's not correct.
  11. Jun 16, 2010 #10
    Yeah, I was about to jump on that myself.
  12. Jun 17, 2010 #11
    my mistake-

    "It takes about a hundred thousand years that the gamma ray generated by the nuclear fusion in the center of the Sun appears on the surface. On the other hand, solar neutrinos arrive at the earth in about eight minutes because neutrinos rarely interact with the matter. Therefore we see the solar activity a hundred thousand years ago by the visible lights, however, it is possible to see the inner of the Sun in real-time by neutrinos."
  13. Jun 17, 2010 #12
  14. Jun 18, 2010 #13
    It is poorly worded, so imagine my embarassment when I went back, read it and realized my misinterpretation. But the information IS from the official Super-Kamiokande website, who the last time I checked is on the forefront of neutrino research.
  15. Jun 19, 2010 #14
    Neutrinos do have non-zero mass; so I imagine that you would see at least some gravitational effect.

    Normally for low-mass elementary particles like electrons you never observe gravitational effects because they're completely swamped by the electromagnetic force, but for a neutrino, which isn't coupled to the strong force or electromagnetism, I imagine you could observe some gravitational deflection in the presence of an extremely strong gravitational field, eg. a neutron star or black hole.
  16. Jun 19, 2010 #15
    I think the number of neutrinos is 65 000 000 000 neutrinos for seconds...
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