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What is the difference between anti-particle & exotic matter

  1. Apr 20, 2013 #1
    Exotic matter have a negative mass and goes in the opposite direction of the force applied to it. These properties seem like the opposite of normal matter. I heard anti particles travel backwards in time, I can easily imagine a particle falling due to gravity in reverse time as a object that seem to move the opposite direction of a applied force. So what is the difference between anti-particle and exotic matter?
  2. jcsd
  3. Apr 20, 2013 #2
    Exotic matter has neever been experimentally observed and probably it does not exist at all.

    Antiparticles have positive mass and they have been observed already 80 years ago and they have been in use in practical applications for decades every day all over the world in lots of devices and machines (like the positron emission tomography).

    Also, let me quote bhobba: "Anitiparticles do not literally travel back in time - its just a way to describe it mathematically."
  4. Apr 21, 2013 #3
    Oh thx. But do anti particle react like exotic matter when force is applied?
  5. Apr 21, 2013 #4
    No, antiparticles react to "force" in the same way as particles. Electrons and positrons (poistrons are antielectrons) have opposite charge and they are attracted. The positron is not running away from an electron.
  6. Apr 21, 2013 #5
    So why do people mention it seem to be a particle traveling backwards in time.
    I know it's not really doing that but there must be a reason why people say that
  7. Apr 21, 2013 #6
    As with everything in physics, without maths none of it makes sense.
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