# Tag Info

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What you are missing is that it is not a viable strategy to get the probability by counting worlds. The only viable way of calculating the probability in MWI is the Born rule. See this paper especially section 9: http://arxiv.org/abs/0906.2718.

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I don't really know what the questioner means by whether the MWI makes a calculation easier or more elegant. I can think of calculations that cannot be done in any other interpretation because they deny that quantum mechanics applies to macroscopic objects. For example, David Deutsch and Patrick Hayden explained how correlations are established between the ...

0

Your observation is correct. If tossing a coin were a quantum measurement, in the many-worlds interpretation of quantum mechanics (MW), there would be a branch of "worlds" in which the outcome was always heads. This would not violate anything we know about probability or quantum mechanics. The full ensemble of worlds would have the expected binomial ...

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Without entering the quantum mechanics of the situation, we can see that each toss is a new world. The next toss is another world, so the series of heads do not add in the way you think to make a world of all heads. Each world deserted by each new toss will have the usual probabilities of heads or tails. A world of all heads is possible with sequential ...

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I would guess, and it can only be a guess, that Stewart is referring to weak measurement. There is a rather vague description of this in New scientist. Annoyingly I can't track down the original paper, but if Stewart's book was written in 2013 the timing fits.

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I can give you one example. In a semiconductor reverse-biased p-n junction, a potential barrier exists that prevents electrons from crossing the junction. There is an energetically-forbidden region in the vicinity of the junction. The wave functions of electron states in both the valence and conduction bands are real exponential in this region. ...

-1

Quantum Computation is testing the validity of QM. Which I guess is an interpretation to those people that think that QM is written in stone at the base of the universe. So it is testing interpretation, and thus may change it. Real physical attempts at Quantum Computation lean heavily on QM working perfectly. So these are then experiments in the validity of ...

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Am I missing something here? Photons and the double-slit experiments do the trick. Likewise, you can entangle the polarisation degrees of freedom of photons. This is inherently quantum and photons aren't charged. True, they are the excitations of electromagnetic fields, but they are not charged. Anyway, I guess the problem here is that except for the ...

0

Every great physical theory has been proven wrong. That's of course not (yet or ever) true, but if history is any guide, physical theories fail. Newton's gravity is a prime example. Even Newton could see problems in its foundations, yet it is highly accurate and can be used to guide satellites and space probes. By questioning those foundations (and other ...

4

Every particle that interacts with something is charged -- in some sense. We say that particles are charged under a certain interaction if they are affected by that interaction, and their charge measures how strongly they interact. But what you seem to be asking about is electric charge. Then one idea of an observable phenomenon could be quark confinement. ...

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Weak and Strong interactions do not involve charge. Strong interactions involve color charge, which is a different property than "normal" charge. The weak interaction mostly involves flavor change. As to your non-charge dependent Quantum Mechanical effects, we have tunnelling. See for example this link.

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The existence of "bosons" is already a consequence of QM -- the notion of indistinguishable particles and the resulting Bose-Einstein (as opposed to Maxwell-Boltzmann) statistics is manifestly not a classical phenomena. Classical particles are always distinguishable, since "that particle there" has a complete set of observables that classically commute with ...

0

I think you are prejudiced yourself if you say 'I do think superdeterminism is the most natural approach to how the universe works'. This is not meant as criticism, I just want to say that your mind is shaped by the world you perceive, and that world looks deterministic. Quantum mechanics and its randomness represent a different view on the (microscopic) ...

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The real issue here is obscured by inane terminology and bad thinking. The real issue is, what sort of "locally deterministic theory" could reproduce the experimentally successful predictions of quantum mechanics? Locality here means, not just that causal influences have to pass through space (rather than acting instantly at a distance), but that they ...

1

Ideas shouldn't be treated as jokes but superdeterminism is false: it is incompatible with the best available theory of knowledge. First, a digression on the theory of knowledge. Any instance of adaptive complexity has to be explained. For example, as Paley noted, if you find a watch and notice that its parts fit together in such a way that they accurately ...

3

Why is superdeterminism generally regarded as a joke? My personal (somewhat facetious) answer to that would be because people lack imagination. I don't think of superdeterminism in terms of conspiracies, but rather retrocausality, and do not find it ridiculous if phrased this way. Basically, I don't believe there's really something like a physically ...

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First of all, "loopholes" is no disrespect. It's standard nomenclature. Given a law, a "loophole" is a way to circumvent it. Bell's inequalities, in their mathematical formulation, are laws that prevent superdeterminism, so if we believe it should exist, we have to find loopholes in the assumptions. It might be that the loophole is so big that the whole law ...

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You say "ridiculous sounding ideas often end up becoming standards science" - but take into account that "ridiculous sounding ideas" much more often, by a large factor, end up becoming no science at all. I agree that "that form of idealogical bullying should never exist" - except that it's not ideological, but just a practical matter of deciding which ...

2

There are published deterministic alternatives to the indeterministic Copenhagen interpretation of Quantam Mechanics. De Broglie–Bohm theory is the most well known. David Bohm wrote a book The Undivided Universe: An Ontological Interpretation of Quantum Theory just before he died in 1992, with Basil Hiley. The book explains Bohm's deterministic ...

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At least to me, it is unclear what it means to be "measured by the environment". As far as decoherence is concerned the situation is however quite clear. Already the original "einselection" framework of Zurek is applicable to bipartite system/environment scenarios. Let $(| p\rangle)_p$ be a "pointer basis" for the system. Then any Hamiltonian of the form ...

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If you want to insist that a classical theory of hidden variables can reproduce the predictions of QM, no one can say you are wrong (just stubborn). But if you admit one more thing, that physics ought to be local, then we've got you! So without thinking about your model in detail, I can say that such a model might reproduce the predictions of QM, but it ...

1

There are two misconceptions in your examples and there is another misconception in the reply to your question by anna v. The first problem concerns what happens when a person chooses whether to turn left or right. If the person in question has a reason to go to a specific place and he has to turn left to do so, then he will turn left with extremely high ...

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