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Speed of a tachyon increases as its energy decreases

  1. May 3, 2013 #1
    I Found This in Wikipedia ''the speed of a tachyon increases as its energy decreases. In particular, approaches zero when approaches infinity'' and My question is How can be this Possible ?! First I know ,When the speed of a particle increase, his Energy will increase Too , No ? Second How Can The speed Be Infinity ?! and Finally Why we create The Tachyon , Einstein said that the Photon is the Fastest ,so what the purpose of Tachyon why we create it ?!
  2. jcsd
  3. May 3, 2013 #2


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    Gold Member

    The tachyon is a mathematical construct that is not believed to exist in the real world.
  4. May 3, 2013 #3


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    Staff: Mentor

    Exercise: find the (relativistic) formula that gives a particle's speed v in terms of its energy E and mass m. You will find that it contains an m2.

    Tachyons, if they exist, have imaginary mass: m = iμ where μ is a real number. (iμ)2 = -μ2. In the formula that you get in the exercise above, this changes a sign, which in turn produces the behavior of v with respect to E as described in Wikipedia.
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