Negative mass

  1. does negative mass exists?
     
  2. jcsd
  3. it says it hasn't been proven if it is exist however, by mathematics, it is supposed to react just like electromagnetism except that like masses would attract and opposite would repel. Now, does anybody think he can explain the exception?
     
  4. An antiparticle would have a negative rest mass
     
  5. Ah... any proof for that? Antiparticles do not have negative rest mass.
     
  6. So is that it, there are no more theories on negative mass?
     
  7. According to the feynman's theory of positrons, the proper time for an antiparticle the reverse of the proper time for matter. The proper mass would be reversed as well. All invariant quantities would be reversed for
    antiparticles.
     
  8. but we aren't sure that antiparticle exists either. As far as I know, the only reason we even believe in antiparticles is b/c of them, we laws make sense b/c when you exclude them from theory, our physics seems flawed, still a lot of physicist don't believe in it though coz we don't have a brute evidence for it.
     
  9. selfAdjoint

    selfAdjoint 8,147
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    Boy, if the antiproton doesn't exist, the Tevatron physicists must have made up all of that data they've published. You think?
     
  10. We are sure they exist. CERN even has an antimatter factory. :!!)
     
  11. Only reversed in time. It has the same mass. Check out the Particle Data Group.
     
  12. Hi Norman,
    Sorry to appear obtuse, but once I learned that antiparticles were reversed in time, I jumped to the conclusion that all invariant quantities were reversed for antiparticles. Please follow me to the QM forum where I
    re-posed my question.
     
  13. selfAdjoint

    selfAdjoint 8,147
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    Try googling on CPT Theorem.
     
  14. I'll check it out - Thanks!
     
  15. I didnt even know that antiproton exist, I guess I shouldnt argue you guys about these things, so far, I am only aware of 3 anti things, antimatter, antiparticle, and anti proton. Are there anymore?
     
  16. selfAdjoint

    selfAdjoint 8,147
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    Antimatter is the collective name for the antiparticles. The modern way of looking at it is, every particle has a corresponding antiparticle, but sometimes the particle is its own antiparticle. This is like saying every quadratic equation has two solutions, but sometime the solutions coincide; it's perhaps just a manner of speaking but it makes thinking about antiparticles a little smoother.

    So all the particles in the standard model come with antiparticles. That's six quarks, six leptons, four electroweak bosons (including the photon) and eight QCD bosons, the gluons. Therefore all those numbers I gave except one should be doubled. The one exception is the four electroweak bosons. It is required that an antiparticle have opposite charge to its particle; so for example the electron is electrically negative and therefore the positron (as the antielectron is called for historic reasons) has to be electrically positive.

    The electroweak bosons consist of the photon, which is electrically neutral, the W+ and W- particles, which are each other's antiparticle (guess which one is positive and which one negative), and the Z0 particle, which is also electrically neutral. Since they have no charge to reverse, the photon and the Z0 are their own antiparticles.

    The point about charge reversal applies not only to the familiar electrical charge, but to the triple "color charge" of QCD; each of its three varieties comes in a "positive and negative" form (the "negative" one is called an anticharge), and the gluons which are elctrically neutral each carry a pair, consisting of one of the three color charges and one of the three anticharges, but not the anticharge of its charge. And that gluon's antigluon carries the opposite one of each of that pair. So if they meet and annihilate, the total QCD charge of the event comes out to zero, as it should.
     
  17. chroot

    chroot 10,426
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    Every known particle has an antiparticle.

    - Warren
     
  18. What you said completely made sense to me selfadjoint but the analogy you gave didn't sound right to me, rather I'd like to use the analogy that every equation has an inverse but for the equation that don't, here though, their inverse is the same equation.(this isn't mathematically correct but seems more logical to me)

    btw, I also heard something about antiparticles that they have inverse time and space(guessing this one) too which didn't make sense to me, could you guys explain this to me?
     
  19. selfAdjoint

    selfAdjoint 8,147
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    You are driving the analogy too hard. I wasn't trying to model antimatter in high school algebra, just the community habit of treating the exceptional case as a normal case with an asterisk.

    In the math, you can do a transformation t -> -t and that transforms the expression for a particle into one for its antiparticle. People with gee-whiz aspirations can read into that whatever they like but it's emphatically just a symmetry of the math, not a fact of nature.
     
  20. so you don't believe that it have has inverse time and maybe space?
     
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