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Newtonian Quantum

  1. Jan 14, 2016 #1
    First. Do you consider Copenhagen Interpretation as leftover of Newtonian days when things are classical? Because in Copenhagen you have to divide with a classical and quantum cut that modern Decoherence tries to overthrow. .

    Second. And this is about the thread "Quantum mechanics is not weird, unless presented as such" made by Arnold Neumaier. Since mostly experts discuss there. I don't wanna disturb it by asking such simple question in that thread. Can we say Arnold Neumaier stuff is an example of Newtonian quantum by newtonianizing QFT? For example. In the double slit experiment. Archives search in 2011 produced the following Neumaier statement "It arrives at the various places of detector with different intensities, and these intensities stimulate all the electrons. But because of conservation of energy, only one can fire since the first one that fires uses up all the energy available for ionization (resp. jumping to the conduction band), and none is left for the others". He calls this the thermal interpretation. Does he still believe this? Hope he can answer in this newbie thread.

    Basically. Neumaier's 'thermal interpretation' gives the fields described by QFT an ontological status, rather than considering them a computation tool (as some people do). Isn't this like leftover from the Newtonian classical days?

    Anyway. Someone named Camper critiqued Neumaier statement of the above (hope Neumaier can address the following here as it is the meat of the issue):

    "I'm sorry - this sounds like nonsense to me. He says only 1 electron in the detector responds because of conservation of energy. What happens when the screen is the inner surface of a hollow sphere a light-year across, and the emitter is a point source dead in the middle emitting a spherical moving quantum field? How is the energy transported across space via the quantum field? Across the whole wave front? In which case, what kind of process involving conservation of energy takes place around the whole surface of the sphere instantaneously when the wave hits the screen? How does this work? if you wish to provide an 'interpretation' one must do more than simply state something happens."

  2. jcsd
  3. Jan 14, 2016 #2


    Staff: Mentor

    No. Like many interpretations its simply an argument about the meaning of probability:

    What you may be alluding to is, like many (but not all), it assumes the existence of a classical world the observations appear in. This leas to circular reasoning in using QM to explain that world. It doesn't invalidate it or anything like that, but its a blemish best fixed. It can be overcome, but that's a whole thread in itself to do with decoherence. Start one if you are interested.

    Last edited: Jan 15, 2016
  4. Jan 15, 2016 #3


    User Avatar

    Staff: Mentor

    I think you are misunderstanding what decoherence does. It doesn't eliminate the classical/quantum cut, it provides a justification for making that cut at a particular place.

    It is important to understand that decoherence is the result of unitary evolution of the quantum system (including the environment) according to Schrodinger's equation. Thus, it is present no matter what interpretation you happen to be using; when different interpretations handle decoherence differently, that tells us more about the interpretation than about the phenomenon of decoherence.

    It also important to know that (despite some initial optimism) many people find that decoherence has not eliminated the measurement problem as it is most generally understood. It explains why we observe macroscopic superpositions only in systems that have been carefully set up to avoid decoherence and hence why observed outcomes are always classical - but it does nothing to explain why we get one outcome instead of another.
    Last edited: Jan 15, 2016
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