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Antimatter at c

  1. Jul 5, 2009 #1
    what happens to anti matter traveling the speed of light?
     
  2. jcsd
  3. Jul 5, 2009 #2

    D H

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    Antimatter particles have non-zero mass, so they cannot travel at the speed of light.
     
  4. Jul 5, 2009 #3
    doesnt matter also have a non-zero mass
     
  5. Jul 5, 2009 #4

    ZapperZ

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    Which is why they also don't travel at c.

    There's no difference between matter and antimatter in this respect.

    Zz.
     
  6. Jul 5, 2009 #5
    so is it theoretically possible to convert antimatter into energy, the way matter can be converted into energy such as a nuclear reaction?
     
  7. Jul 5, 2009 #6

    ZapperZ

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    In [itex]E = mc^2[/itex], you'll note that that "m" doesn't discriminate between matter and antimatter.

    Zz.
     
  8. Jul 5, 2009 #7

    DaveC426913

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    A very easy way of turning anti-matter into energy is to simply let it escape its magnetic bottle. The moment it contacts matter, both will be converted - rather enthusiastically - into gamma radiation.
     
  9. Jul 5, 2009 #8
    i was under the impression that matter antimatter annihilation resulted in space, which is to say that if one had a closed system of space which contained a particle of matter and a particle of antimatter and they annihilated the net amount of space in the system would increase
     
  10. Jul 5, 2009 #9

    DaveC426913

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    Not to my knowledge. no.

    The result would be a flash of gamma radiation.
     
  11. Jul 5, 2009 #10
    is there any fraction of matter left over after annihilation, or is it a total conversion of the matter involved into energy
     
  12. Jul 5, 2009 #11

    ZapperZ

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    Where do you actually read these things?

    On second thought, maybe I don't want to know.....

    Your impression is not correct. If it is, then Fermilab would be producing "space" a gazillion times a second right now.

    Zz.
     
  13. Jul 5, 2009 #12

    DaveC426913

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    You could of course, have incomplete mixing of the two reactants, but that's not the same thing.

    For every atom of matter that combines with an atom of antimatter, you will get an amount of energy released defined by E=mc^2, and no matter left over. It is a 100% conversion of matter to energy.
     
  14. Jul 5, 2009 #13
    lol sorry z, i don't remember where or when exactly i got confused about that. 100% energy conversion? so if physicists can create anti matter, and use it to annihilate matter into what i assume is a massive amount of gamma radiation on a scale with the atomic bomb, isn't that basically the same or better as cold fusion?
     
  15. Jul 5, 2009 #14

    ZapperZ

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    You're forgetting that it takes A LOT OF EFFORT, under normal terrestrial condition, to create antimatter and to contain them. This is a highly inefficient way to generate energy.

    Zz.
     
  16. Jul 5, 2009 #15
    in steven hawkings new series on the sci channel aptly named "master of the universe" he says "in empty space this energy takes the form of pairs of subatomic particles that emerge out the void, exist for less than a nano second and then annihilate each other. so the idea is, out of nothing if you like, a pair of particles is created and then exists for a short time and then annihilates and that's happening through out space" how is this possible? and why doesn't this light up the universe with the resulting gamma radiation?
     
  17. Jul 5, 2009 #16
    because i was under the impression that annihilation created space, i assumed that this explained the expansion of space
     
  18. Jul 5, 2009 #17
    and also
    but has there ever been any testing done on antimatter in the form of breaking the bonds of the nucleus to release energy as with the atomic bomb. does anti atom have a strong force?
     
  19. Jul 5, 2009 #18

    ZapperZ

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    This is the "free energy" nonsense that many crackpot are trying to push. If there is THAT much pair production out of empty space, then our universe would have been opaque, and we would not have to go to such a difficult extent to detect the Casimir forces.

    Your impression is incorrect.

    Zz.
     
  20. Jul 5, 2009 #19
    so are you saying this isn't proven, by what mechanism do they explain how matter and antimatter are being created out of nothing? the validity of this in mind seams easy to test, wheres all the radiation from them?
     
  21. Jul 5, 2009 #20

    ZapperZ

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    What isn't "proven"?

    Vacuum fluctuation has been shown to be valid, per the Casimir effect. However, the speculation that one can harness significant energy, the way you are equating it with nuclear energy, so far has been shown to be a fallacy.

    Zz.
     
  22. Jul 5, 2009 #21
    Hi 77,

    I have not heard that before, but it is an interesting hypothesis! If particles pop into existence and then annihilate each other, becoming gamma ray radiation, then we have something for nothing. But that is what Allan Guth says we have: "The universe is the ultimate free lunch." The same would be true if the annihilation became more space instead of gamma rays. In one case we have light energy, in the other case we have dark energy.:cool:

    -S
     
  23. Jul 5, 2009 #22
    Fermilab usually has over 1012 antiprotons (about 0.2 microCoulombs) circulating in the 6,280-meter-circumference Tevatron (beam tube diameter about 7.5 cm) at about 980 GeV (gamma = 1044, beta = 0.999 999 5). Each annihilating antiproton at rest would release about 3 x 10-10 joules, so 1012 annihilating antiprotons will release about 300 joules of energy (note: TNT has about 4000 joules per gram). Most of the 980-GeV antiproton energy is kinetic, not in its annihilation mass.
    Although most of the annihilation energy initially produces pions and other mesons, eventually it all converts to ionization energy (heat) plus (aniti)neutrinos.
    See http://www.fnal.gov/pub/about/experiments/index.html#list
     
  24. Jul 5, 2009 #23

    DaveC426913

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    Wait. When did we say this?

    Virtual particles, created from vacuum then recombining again is not the same thing as matter and antimatter. This is mixing two separate phenomena.
     
  25. Jul 5, 2009 #24

    DaveC426913

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    An atom of anti-matter is identical to an atom of matter is every way except the charges on its components. In anti-matter, the anti-proton(s) have a negative charge and the anti-electron(s) have a positive charge.
     
  26. Jul 5, 2009 #25
    When the particles "pop into existence", they still have to obey e=mc^2 - it takes energy to create this mass. When they annihilate each other, they create the gamma radiation, which has exactly the same energy as it took to create the two particles. All that is happening is that for a very brief moment energy is turned into matter and then back into energy.
     
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