Antimatter and Antigravity Connected ?

  1. Antimatter and Antigravity Connected ???

    The matter in our universe is controlled by gravity which is a long range force obeying the inverse square law. In the large, antimatter cannot be found by astrophysicists and cosmologists. So the assertation that the universe is dominated by matter only is a fact of all experimental verifications. But in the small, the existence of antiparticles were proved facts. The quantum world is dominated by three fundamental forces: EM force, strong force and weak force. Gravity force has no effect at all in the quantum world asides from the black hole singularity domain and relativistic mass where the concept of extremely large mass (matter) is concerned. But if it takes large neutral mass (matter) to make gravity effective, would it also takes large neutral antimatter to make antigravity effective to the point of being detectable? So if a Cavendish experiment is made entirely of antimatter, can the G be repulsive? Matter attracts but antimatter (in the large) repels.
     
  2. jcsd
  3. jcsd

    jcsd 2,226
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    We can be fairly certain that the universe is dominated by matter, not antimatter, as though on the whole a large collection of antimatter looks almost exactly the same as a large lot of matter, if regions of matter and antimatter meet they anihilate each other emitting a copious amount of radiation. It is this radiation we would see if there was any large amoun tof antimatter in our universe.

    The graviational force between matter-matter, antimatter-matter, antimatter-antimatter is always attractrive.
     
  4. Pardon me, is this an experimental fact? If it is, please let me know what experiments were done in the past that I am not aware of.
     
  5. jcsd

    jcsd 2,226
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    It's a clear result from the theory that predicted antimatter, to be honest I don't know if it's ever been tested, but if this were not the case I imagine that's the whole of relatistic quantum mechanics/quantum field theory out of the window.
     
  6. Not necessarily so, the quantum world of particles and antiparticles is dominated by other forces not gravity. But the symmetric general relativity equations does not take into account the antigravity force. The gravity force is replaced by the curvature of spacetime and the cause of curvature is ordinary matter not antimatter.
     
  7. jcsd

    jcsd 2,226
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    No, it is a fairly basic feaure of particles that they have the same mass as their antiparticle.
     
  8. I agree and that's the mystery of it! If they are the same mass and saying the other properties like charge and spin have nothing to do with the formation of neutral matter or neutral antimatter is an incorrect assumption.


    edits: add experiments

    Two related experiments: J. J. Thomson determination of the mass-to-charge ratio of the electron and Millikan's oil drop experiment. Both of these used the concept of the electric field and magnetic field to find the constants of mass-charge ratio and the unit of charge. Along with the electric and the magnetic force, the other implied bystander force of these experiments is the inertial force of Newton's 2nd law of motion. Newton's 2nd law of motion, [itex] F=ma [/itex], mentioned an acceleration. This might not be the absolute acceleration that physicists are looking for. Newton, Mach and Einstein were all looking for this absolute acceleration. I think a complete understanding of this specific acceleration and its relation to a generalized absolute acceleration can find the lost force of antigravity.
     
    Last edited: Jun 30, 2004
  9. I think somehow this generalized absolute acceleration is related to a metric (a unit of length) with the following invariance between them.

    [tex] \vec{a} \cdot \vec{r} = c^2 [/tex]

    where [itex] a [/itex] is the generalized acceleration, [itex] r [/itex] is the metric, and [itex] c[/itex] is the speed of light in vacuum.

    Edits:

    So that gravity is an acceleration that spiral inward and antigravity is an acceleration that spiral outward. And that when these are in balance, the component of centripetal is equal to the component of centrifugal.
     
    Last edited: Jun 30, 2004
  10. Antimater produces a regualar gravitational field like normal matter. You're thinking of exotic matter which has negative mass and therefore produces antigravity.
     
  11. Is this theory or experiment? I don't know of any experiment that verify what you said?
    I am not talking about the EM deflection of positron by Carl Anderson. I am talking about something like an anti-earth which cannot form because antimatter are really repulsive in the bulk.
     
  12. I would like to clearup what I mean when I say antimatter. Antimatter is made of anti-atoms: antiprotons, antineutrons, and positrons. In parts, the antiprotons and antineutrons are made of anti-up quarks and anti-down quarks. All I know is that these antiparticles don't live long enough to form anti-atom hence antimatter cannot be formed by current experiments at low energy.
     
  13. jcsd

    jcsd 2,226
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    IIRC an anti-helium atom has been formed by experiment, but your sill barking up the wrong tree as for example if an antiparticle had negative mass it would completely chnage anihilation as the two rest masses would cancel each other out.
     
  14. Can I request from you more information on this or is it too much to ask?

    I don't think there is such a thing as negative mass. The complete quantization of space does not allow it although there can be two kinds of mass: the kinetic and the potential. Both are positive from my calculations.
     
  15. jcsd

    jcsd 2,226
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    Sorry I menat anti-hydrogen, I'll see if I can find a link.

    Yes but surely as the graviational attraction is proportioonal to the masses of the two objects in order for there to be repulsion there must have masses of opposite signs.
     
  16. jcsd

    jcsd 2,226
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  17. When an electron and a positron interact, the products are photons. This was what Martin Deutsch experiments on positroniums indicated.

    But there are two type of products: (1) two photons and (2) three photons. The positronium that produces the three photons seems to have a longer lifetime than the positronium producing the two photons.

    If electron is formed by 7 [itex]H^{-}[/itex] and 1 [itex]H^{+}[/itex] and the positron is formed by 7 [itex]H^{+}[/itex] and 1 [itex]H^{-}[/itex] and the photon is formed by 4 [itex]H^{-}[/itex] and 4 [itex]H^{+}[/itex] then this can account for the 1st interaction but the 2nd interaction can be accounted only if vacuum is taken into consideration. The vacuum is made of even and odd [itex]H^{-}[/itex] and even and odd [itex]H^{+}[/itex].
     
  18. jcsd

    jcsd 2,226
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    AFAIK the only limit on the products of electron-positron anihilation are the various conservation laws, certainly photons are far from the only product that can be produced by electron-positron anihilation.

    I know we mentioned antihydrogen earlier, but electrons and postirons are fundamehtal particle s certainly not made out of hydrogen ions.
     
  19. I don't know of any other product? Are you talking about lepton number conservation? energy conservation? charge conjugation? parity? or baryon number conservation? strangeness conservation? Time symmetry?
     
    Last edited: Jun 30, 2004
  20. Didn't this experiment merely prove that particles and anti-particles consist of the same basic component - energy (the photon).

    Substituting Energy for Mass when calculating the gravitational force between matter and anti-matter, the result would be the same as if it were like with like.
    This would imply that there is no difference between the mass of matter or antimatter and as such no difference in their gravitational field.

    The only difference between a particle and an anti-particle is the configuration of the energy, all other properties would be the same.
     
  21. jcsd

    jcsd 2,226
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    yep, conservation of 4-momantum and charge being the most obious conservation laws governing decay products.

    electron-positron anihilation can and has been observed to produce baryons and mesons as products
     
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