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Clarification between electron cloud and a wave

  1. Jul 16, 2011 #1
    When I've heard and read about the electron "cloud", orbitals where constantly shifting electrons move at breakneck speeds and we cannot model with certainty but only with probabilities of where electrons are likely to be found, I can't help thinking of a wave. It seems to me that it almost seems like a stationary wave where the frequency of varying spots correlates to a wave. Seems it would be alot simpler to think of it that way instead of a crazy particle that just happens to jump around like crazy. Please give feedback on the difference between a wave model and the quantum uncertainty, orbital model (or are they really the same?). Please provide, if possible, experimental differences as well so that it doesn't turn into a discussion about what is a more jazzy way of looking at things, but is instead grounded in reality. Thank you.
  2. jcsd
  3. Jul 16, 2011 #2
    It seem to me that the dual particle-wave nature is the characteristic of microscopic physics.
    Why do we divide into corpuscular and wave schools?
  4. Jul 16, 2011 #3


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    Some people are still fighting this battle, but more people take your point of view. In my opinion the best approach is to put the questions of "which interpretation is best" aside, and focus on the physical principles that are common to all of them. The fact is that it really doesn't matter whether or not the wavefunction has any objective reality or not .. our experiments still behave in the same fashion. Or more precisely, since no one has yet conceived of an experiment that can get at what is going on "behind the scenes" so that we can objectively measure which interpretation is correct, I think it is better not to worry too much about it until such an experiment can be carried out.

    That is not to say that there is no intellectual or pedagogical value in comparing and contrasting the different interpretations .. quite the contrary in fact, I have learned a lot (and am still learning) from such exercises.

    Anyway, Jacques has a rather strong point of view on this issue (could you tell? :wink:), and his answers to questions like this one are often quite strongly polarized. Despite his claim, I don't think it is generally agreed that the experimental result he is citing proves that the Born interpretation of the wavefunction (which is a fundamental postulate of QM) is incorrect.
  5. Jul 18, 2011 #4


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    Firstly you are not the first person to ponder these questions. You should begin with some good introductory text on QM which discuss this.

    Two phrases in your OP which I note are "...and we cannot model with certainty..." and your last sentence "Please.... ,but instead grounded in reality."

    Firstly a model is a construction which we either observe or hope to observe matches the behavior of some actual physical system.
    Secondly, my thesis advisor taught us (his students) to make a distinction between reality (what is) and actuality (what happens).

    Understand that via the empirical nature of science what happens (in the lab or observatory) is more fundamental as a source of knowledge and truth that what is which we can sometimes infer from the former. Jazzy or not, this is the more proper way of looking at things. Science studies how things behave and sometimes can construct a "model of reality" to fit that behavior. This connects with our day to day experience of updating our world picture with our experiences.

    But this begs some questions:

    1.) "Is our world picture correct? or is there another or many world pictures which equally match our experiences just as well?"

    and the deeper question:

    2.) "Is a reality model appropriate to the phenomena we observe or should we in science stick to describing and explaining phenomena in terms of their relationships to other phenomena?"

    I have found that in order to better understand quantum theory, it is important to explicitly distinguish questions and assertions about the reality of physical systems from the questions and assertions about their actuality.

    In your example of atomic orbitals, quantum theory does an exceptionally good job of describing behavior (the actuality) precisely and accurately. Your questions beg for an understanding of "the reality" as if there must be one. Consider the possibility that any one "reality" is not going to fit all actual behavior, that reality is relative.

    Finally compare this antithesis of intuition with the similar one of relativity of time in Einstein's theory wherein two observers may meet at an instant and yet have very different pictures of "what's happening right now". One's future may overlap the other's past for spatially distant events. (This is not directly related but is another exercise in learning to make explicit and modify what one intuitively believes is "obvious".)
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