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Could neutrino have negative mass?

  1. Jul 5, 2012 #1
    Can anyone think of an empirical reason the neutrino could not possibly have a negative mass; that is any of its states?
     
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  3. Jul 5, 2012 #2

    jtbell

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    Is it possible for anything to have a negative mass?
     
  4. Jul 5, 2012 #3

    Simon Bridge

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    It's unclear what negative mass would mean but empirically the experimentally determined masses indicate that the neutrino mass is positive.
     
  5. Jul 5, 2012 #4

    bcrowell

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    When we discuss negative mass, it becomes necessary to distinguish inertial mass, active gravitational mass, and passive gravitational mass. Which do you have in mind, and what is the motivation for the question?

    (For example, if a test particle has both negative inertial mass and negative passive gravitational mass, then it can obey the equivalence principle.)

    What evidence are you referring to, and which type of mass? Neutrino oscillations only tell us the square of the difference in mass between two states.

    In general relativity, this kind of thing is discussed in terms of energy conditions. Here's a recent discussion of energy conditions: Twilight for the energy conditions?, Barcelo and Visser, http://arxiv.org/abs/gr-qc/0205066

    Dark energy (the cosmological constant) definitely violates various energy conditions, and scalar fields such as the Higgs may as well.
     
  6. Jul 5, 2012 #5

    Simon Bridge

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    Tritium beta decay measurements measure the electron neutrino mass squared - early results pointed to a negative mass squared. I think Troitsk and Mainz did direct measurements that point at a positive mass-squared. Possibly I misread that as positive and negative mass. Darn.

    That leaves the weaker - lack of anything to show inconsistency with a positive mass then. Though absence of evidence is not evidence of absence, that, combined with the elusiveness of the kinds of things that may be expected to be so exotic kinda pushes the burden of proof into the negative mass camp.
     
  7. Jul 5, 2012 #6
    If the Higgs theory is correct doesn't this unify Inertial and Gravitational mass? And if so empirically determined negative mass would display properties of both being gravitationally repulsive to positive mass objects and being accelerated by a force in the opposite direction it is applied?
     
  8. Jul 5, 2012 #7
    I imagine anything with negative mass would be repelled by gravity, thus it might be found in the voids between galaxy clusters in intergalactic space. Seeing as how neutrinos are constantly passing through the Earth, I think it is safe to say that neutrinos have mass, it's just incredibly small.

    Edit: What Voltz said
     
    Last edited: Jul 5, 2012
  9. Jul 5, 2012 #8
    Yes, virtual particles.
     
  10. Jul 6, 2012 #9
    Gee, thanks everybody for your replies.

    Firstly I'm thinking of the type of negative mass that voltz mentioned.
    "display properties of both being gravitationally repulsive to positive mass objects and being accelerated by a force in the opposite direction it is applied".

    The reason I'm wondering about this is: If neutrino's always come in entangled pairs of - and + mass, a fixed distance in their frame apart, then that would in another inertial frame lead to them appearing to have both fermionic and bosonic properties would it not?: and if that where the case, it wouldn't be that great a step to develop gravitronics.

    Just a matter of sub-space engineering. Where sub-space is defined as sub Planck scale interaction. I've posted here years ago why I think that is the case with gravitational interactions.
     
  11. Jul 6, 2012 #10

    DrDu

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    I guess a particle with negative mass can always be re-formulated as a particle with positive mass.
    E.g. in Diracs theory of the electron there are states of the electron with negative energy and mass.
    However we interprete them as states of the positron with positive energy and mass.
     
  12. Jul 6, 2012 #11
    Positrons don't help: thank you anyway.

    Like a monkey on a type writer, I've been playing around with various ways of putting the Universe together using algebraic manipulation of the constants of nature, h, G, c, e, ect.
    What I came up with doesn't interest anyone. However I'm sure people would be interested in an experiment to see if even basic conjecture played out, if the possible result is gravitronics. Meaning firstly, any manipulation of a local gravitational field strength or density at all using neutrino, anti-neutrino flux, would herald the discovery of said. Not using any electromagnetics for pseudo gravitational effects.

    Maybe the Universe has gravitronics as a discovery yet to be made.
    I don't mind embarrassing myself or you by looking, and wondering, and imagining an experiment to test the conjecture.
     
  13. Jul 6, 2012 #12

    Simon Bridge

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    No worries - when you have imagined an experiment, let us know aye. ;)
     
  14. Jul 6, 2012 #13
    Ok Simon, might take a while though.

    Thank's everyone, seems no-one really knows what's going on, especially with neutrino's.
    So like Simon says, I've got to do it myself alone.
    In the unlikely event I get it happening, then others will want to know how it's done.
    I've always thought it too dangerous for me or any one person to have the know-how where no-one else does.
    Others suddenly seems like insects: wouldn't you agree?
    I might go even crazier and decide to rule.
    What then- OOPS?
    I thought it safer for mankind to be a shared discovery.
    If you'll risk it, so will I.
     
  15. Jul 6, 2012 #14

    jtbell

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    When you do it, first get it published in a regular physics journal, then we can discuss it here, as per our scientific discussion guidelines, which you can read by clicking the "Rules" link at the top of any page here.
     
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