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The video in reference : Is This What Quantum Mechanics Looks Like?

At 4:47 to 5:10, he shows a situation meant to be an analogy to a quantum particle going through the double slit experiment and says "there is no randomness, if there is any uncertainty its due to our own ignorance". Would this not imply that uncertainty is not an inherent property of quantum systems, but something we've gotten wrong? The entire video almost also implies that particles are not in a superposition either, but simply described as one. I understand this is all an analogy, but is this not very misleading?

Sorry if this is not the appropriate question/format, still new to stackexchange.

ACuriousMind
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2 Answers2

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No, the video does not imply that the uncertainty principle is false.

But it does imply that you have to be careful/precise to claim what the uncertainty principle is about. It is actually a claim about the wavefunction. In many interpretations of quantum mechanics, we equate that to a claim about the properties of particles. However, the latter is dependent on one's interpretation of quantum theory. The video talks about the de Broglie-Bohm (or pilot-wave) interpretation of quantum theory. In that interpretation, there are two separate quantities: the wavefunction, and the particle. At a fundamental level in that interpretation, the 'uncertainty principle' applies to the former, not to the latter (since the particles have well-defined position and velocity).

That being said, the property that makes the de Broglie-Bohm interpretation consistent with the observations of quantum theory, is that one presumes one is in 'quantum equilibrium', where one equates one's (classical-like) ignorance of the particle with properties of the wavefunction (i.e., Born's rule). In fact, the de Broglie-Bohm interpretation is itself actually an umbrella term for two distinct intepretations: one where this quantum equilibrium is one of the postulates, and another where it is derived as a statistical property/consequence (similar to how in classical statistical mechanics we derive that a classical gas is described by a homogeneous distribution in classical equilibrium). I do not personally work on these topics, so I do not know how one justifies making classical ignorance part of one of the fundamental axioms; seems strange to me.

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"Ignorance with associated probability" and "random selection from a mixed but non-superposed state" are indistinguishable (and you can prove it).

However: superposition implies interference, while the other two don't.

Quantum interference is measurable and has been measured. Therefore superposition describes reality better than ignorance or random selection from a mixed state.

g s
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