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Homework Help: Mechanism of Einsteins equation

  1. Apr 29, 2007 #1
    1. The problem statement, all variables and given/known data

    What is the exact mechanism through which mass converts into energy and vice versa through Einstein's equation.In other words,what are the conditions under which this transformation happens and why?

    2. Relevant equations


    3. The attempt at a solution

    Some argue that mass is the condensed form of energy so my question is invalid.
    I think it's valid even then.The question says "What are the conditions (and why these conditions only) under which this condensed form of energy converts into its free (usual) form and vice-versa?"
    I don't know the answer that's why I am curious to it.I have asked many people, even my teachers, but couldn't get a satisfactory answer.
  2. jcsd
  3. Apr 29, 2007 #2


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    Science Advisor
    Homework Helper

    To say mass is a condensed form of matter is really oversimplifying. A single electron cannot convert itself into energy (photons) since that would violate any number of laws, conservation of charge, spin, lepton number etc. An electron-positron pair can since they can form a combination which in which these quantities can be conserved by the resulting radiation. Matter is not just an amorphous blob of condensed energy. It has rules of its own.
  4. Apr 29, 2007 #3


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    Gold Member

    I emphasize what Dick has said - matter is not condensed energy.

    In nuclear fusion and fission, no actual particles are converted to energy. It is binding energy that is released.

    However, matter and anti-matter particles can anihilate each other to produce EM radiation. In the presence of a strong E field, EM radiation can give rise to particle anti-particle pairs.
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