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What exactly is a postulate?

  1. Jun 24, 2005 #1
    If some one could explain the concept it would be most apreciated.
  2. jcsd
  3. Jun 24, 2005 #2


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    It is something that is assumed at the "beginning" of a theory. The remainder of the theory's predictions are conclusions derived from its postulates. Postulates can be tested for correctness, but they are assumed, not derived.

    Some examples of postulates:

    The speed of light is constant for all observers.
    Gravitational and inertial mass are the same.

    - Warren
  4. Jun 24, 2005 #3


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    Each physical theory should be endowed with an axiomatical structure.From my reading and understanding experience,the best of them all is the one of (Nonrelativistic) Quantum Mechanics.Each if its 6 axioms has more fomulations (wording and mathematical expressions) depending upon the formulation of the theory:Dirac's (a.k.a.traditional),von Neumann's,Feynman's,...
    There's one postulate (the IV-th,i.e.the time evolution postulate) which,in every formulation aforementioned,can be expressed in 3 different ways,depending upon the picture one adopts:Schrödinger,Heisenberg or interaction (a.k.a.Dirac-Tomonaga-Schwinger).And then of course you have the representations:eek:ccupation number,occupation number-energy,position,momentum.Then of course you have the original formalism of matrix mechanics and wave mechanics,but this is not really a part of the axiomatical structure,as one finds them as particular realizations of the various ways of describing the concept of "physical state".

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