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-1

Is quantum mechanics on a measurement level a deterministic theory or a probability theory? If we know the quantum state of a (ideal) closed system, then we have the probability distribution of measurement outcomes for any of its observables. The state evolution is deterministic, measurement predictions are probabilistic. The probabilities here do not ...


0

I had the same thought a few years before you did. As I understand it - and I'm still thinking about this one - your question is excellent - when this happens out and about, all information about what the system was is lost within the system itself when it 'collapses' due to a measurement. There is nothing in the system itself which retains information about ...


1

Schrodinger, I take it, was dramatising the epistemological and ontological paradoxes implicit in QM by considering a cat as opposed to a particle contained in a box; and hugely succesfull too, as we're still discussing it almost a century on, and its probably more widely known that his eponymous equation. Cats, compared to particles, are vastly macroscopic ...


-3

For the cat (which is the subject of the experiment), it is irrelevant if you observe it or not. Its state will be the same at a given 't'. Also, that state is not dependent on the observation happening or not (although, opening the door when the cat is alive will influence the cat's behavior, but that is another matter). Universally, it is the observer ...


0

The cat has no quantum state, it is a classical object, which, along with everything else in the experiment, is just "overhead" to make it accessible to the general public. There is the decaying lump of radioactives, and the Geiger counter (detector). This is the quantum level stuff; the rest is just classical embellishment. It makes no sense whatsoever to ...


4

In Schrodinger's cat experiment, the scientist is assumed to be an "classical observer" of the state of the cat, and thus all observations made by the scientist are assumed to be classical observations adhering to physics as we knew it before quantum mechanics came along. The thought experiment focuses on what sorts of statements about reality that ...


4

Large classical objects such as cats or humans are next to impossible to place in a superposition of states. They basically decohere immediately. As far as i know the largest object placed in a superposition is a micromechanical resonator and there is currently work being done on placing a bacterium in a QM superposition ( quantum superposition of a ...


5

This is an excellent question and stresses one of the weird features of quantum mechanics. Indeed, the scientist would in turn be in a superposition. And we could even measure this if we'd be able to maintain coherence of such large systems. Ultimately, your question is asking for the solution of the Measurement problem: Why don't we see any ...


29

In a bubble chamber experiment, film was the detecting medium, but film was taken automatically, by the thousands of frames. These bobbins of film went to the various laboratories involved in the experiment, and were scanned for interesting events which were measured and the cross sections for the interactions recorded. This is a clear example of an ...


34

This is is known as the Wigner's friend thought experiment. According to the many World's interpretation, the superpositions are not a problem. The whole universe ends up in a superposition where all experimental outcomes are realized, but such a superposition is entangled with the environment, from a macroscopic point of view it takes the form of a ...


8

It depends of what interpretation of quantum mechanics you are using. By interpretation it is meant that the mathematical predictions of the quantum mechanics formalism are the same, but the philosophical meaning of each is what differs. In the copenhagen interpretation that you seem to describe, the wave function collapses when a conscious observer makes a ...



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