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Newtons law

  1. Mar 28, 2004 #1
    hi,

    Before i begin i am not sure where to put this post wether here or in the general section.

    Is newtons 3rd law broken?

    Neutrinos dont follow this rule. the neutrinos can just pass through particles. so dont they break the 3rd rule? :confused:
     
  2. jcsd
  3. Mar 28, 2004 #2

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    When a neutrino passes undeflected through the earth, there is no violation of the 3rd law since neither the neutrino nor the atoms making up the earth are reacted upon.
     
  4. Mar 28, 2004 #3

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    Benzun,

    Regarding the quote under your name, what precisely would constitute victory to God?
     
  5. Mar 29, 2004 #4
    i think this is a bit religious.
     
  6. Mar 29, 2004 #5
    i believe that action is the passing of the neutrino through the other atom and there is no reaction.

    according to the law you cannot touch (pass) something without touching it.
     
  7. Mar 29, 2004 #6

    selfAdjoint

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    What law is that? Where did you see it?
     
  8. Mar 29, 2004 #7

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    Benzun,

    May I suggest that you are going by (1) everyday experience, where contact forces are the result of a huge number of interactions per second, and maybe also (2) bubble chamber photographs, where the number of interactions is modest. In the latter case, I believe there are bubble chamber photos that are interpreted as neutrino reactions. For instance, neutrinos from the Sun or from a nuclear reactor enter unseen (since neutrinos obviously have no electric charge), and then, despite the tiny coupling to matter, happen ever so rarely to interact. One can measure the momenta and energies of the outgoing charged particles, and thereby infer what the momentum and energy of the incoming neutrino must have been.
     
  9. Mar 30, 2004 #8

    HallsofIvy

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    No, that's not what Newton's laws say. It is not a matter of the neutrino "passing through", say, an electron or a proton in some mystical way: all of those particles are so small that the odds on them "colliding" directly are infinitesmal anyway (and in quantum mechanics, that's not what happens anyway). Even classically, electrons and protons "interfere" primarily by affecting one another with their charges- a neutrino does not have a charge which leaves everything up to it gravitational field (again, the odds on it getting close enough to another particle for the weak and strong forces to come into play are infinitesmal). A neutrino has so little mass its gravitational field does very little. That's why a neutrino can "pass through lead".

    Of course, all those "infinitesmal odds" are not 0: given enough lead and even a neutrino has some chance of being stopped.
     
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