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Wave: Probabilistic wave or physical wave?

  1. May 11, 2005 #1
    I keep debating an argument with a buddy of mine.
    And I've come to teh conclusion that I'm not sure what WAVE natur of light refers to.

    []Does it refer to teh Quantum Terminology(found in griffiths for shro. eq'n) which is WAVE = Probabilitic Location of Particle.

    []Does it refer to a physicsal existance of a wave like vibrating a string
  2. jcsd
  3. May 11, 2005 #2


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    There is no physical wave - there is no medium for transmission (19th century physics postulated ether for this purpose - it doesn't exist). QED (book) by Richard Feynman gives as good a description of what's going on as any.
  4. May 11, 2005 #3


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    The wave nature of light is classical. It refers to the fact that light is an electromagnetic wave, i.e. an oscillating electric field and magnetic field. See http://scienceworld.wolfram.com/physics/ElectromagneticWave.html and notice how the first two equations represent progressive waves. This java applet shows this wonderfully: http://www.phy.ntnu.edu.tw/java/emWave/emWave.html [Broken]
    Last edited by a moderator: May 2, 2017
  5. May 11, 2005 #4


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    The so called "wave-function" in quantum mechanics is not a physical wave, because it exists in phase space rather than physical space. For instance, for two particles, the wave function exists in a 6-dimensional space.

    Classically, light is a wave because the electric and magnetic fields of which it is composed both obey the wave equation.

    So the second answer is perhaps the closest to being correct, except that it should be understood that there is no physical "string" vibrating to transmit a light wave, instead there is simply a set of electric and magnetic fields that obey the same equations that a vibrating string obeys.
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