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Fundamental forces

  1. Sep 17, 2004 #1
    so could anyone tell me

    was is
    weak nuclear force

    and electromagnism force

    and storng nuclear forces thank you!
     
  2. jcsd
  3. Sep 17, 2004 #2

    selfAdjoint

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    The weak force mediates radioactivity. The fundamental interaction is that a neutron emits a weak boson, decaying into a proton, and the weakon then decays into an electron and an antineutrino. In QCD, the theory of subnuclear particles, the weak force is the only one that can change a quark anto a different quark.

    The strong force is the one that holds neutrons, protons and the various other hadrons together, and indirectly it holds the nuclei together. Basically it is carried by bosons called gluons, and affects only the quarks. It has three charges (with their anticharges, and its behavior is mor complicated than the other forces.

    The electromagnetic force is the one we are most familiar with. The electron, its antiparticle the positron, and the quarks all have electric charges. The quarks have both electric and strong charges, which are different. In current theory, which is strongly supported by lots of experiments, magnetism is the relativistic consequence of moving electricity. Electromagnetism is carried by virtual photons.
     
  4. Sep 17, 2004 #3
    i was also told that electromagnetic force and weak nuclear force are the same type how come?
     
  5. Sep 17, 2004 #4

    Early in the history of the universe, the theory is that all four fundamental forces, gravity, electromagnetic, weak nuclear and strong nuclear, were unified into one grand force. As the Universe expanded and cooled and various symmetries were broken, these forces split into the four seperate forces we see now. To test this some experiments were done that succeeded in "reunifying" the electromagnetic and weak nuclear forces into one force called the electro-weak force. I think this is what you are referring to.
     
  6. Sep 17, 2004 #5

    selfAdjoint

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    But even today, the electromagnetic and weak forces are united into the "electroweak" theory, which forms part of the standard model.

    The fully symmetric form of the theory has four bosons, and they would all be massless "gauge bosons". But the symmetry is broken at our low energies; the actual bosons are mixtures of the pure four, in pairs. Two of them mix to form the W+ particle and its antiparticle the W-. Both of these acquire mass through the Higgs mechanism. The other two gauge bosons mix to form the photon and the Z0 particle, but here the other properties of electromagnetism force the photon to be massless, and the Z0 gets all of the Higgs mass. These four "phenomenological" bosons, W+, W-, Z0, and photon, carry the electroweak force, which at longer ranges reduces to electromagnetism. The weak force is short range because of its massive carriers.
     
    Last edited: Sep 17, 2004
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