This tag is for questions relating to what, if anything, the quantum mechanical formalism and experimental results say about the way the world works.

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Why is the Copenhagen interpretation of quantum physics the most widely accepted one?

I've been digging a lot into quantum physics in the last few weeks. I didn't care much about the maths, just about what empirically happens to get a conceptual idea about quantum phenomena. The most ...
4
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1answer
124 views

Are different interpretations of quantum mechanics empirically distinguishable?

Are the different interpretations of Quantum mechanics just different viewpoints of same physical reality? or the experiments can distinguish them? i mean are they empirically distinguishable or not? ...
9
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3answers
225 views

Does quantum collapse involve a loss of information? Does it require energy as suggested by the Landauer Limit?

I read in the context of quantum computing or of the minimal energy required for computation that there has to be a minimum possible amount of energy required to change one bit of information, called ...
2
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0answers
62 views

Are universally valid possibilistic theories possible?

This is a spin-off of the following question: Are Thomas Breuer's subjective decoherence and Scott Aaronson's freebits with knightian freedom the same things in essence? Given that Thomas ...
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3answers
182 views

The need for a 'particle description' of electrons

Is there any phenomenon where the 'wave description' of the electron's motion is not applicable? The reason for this question is to find out if there are any situations were quantum wave theories ...
1
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1answer
64 views

Hugh Everett's MWI [closed]

According to Hugh Everett's many worlds interpretation, all the possibilities of one action can happen at the same time in other parallel universes, so how come we can't see these worlds? now I bumped ...
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0answers
46 views

Is relational QM experimentally distinguishable from standard QM?

Some people advocate for relational quantum mechanics, which is an interpretation (or at least Wikipedia calls it an interpretation) of QM where quantum states are thought of as representing a ...
3
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0answers
347 views

Does the extended probability ensemble interpretation of quantum mechanics make any sense?

Gell-Mann and Hartle came up with the extended probability ensemble interpretation over here. Basically, they extended probability theory to include real numbers which may be negative or greater than ...
1
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3answers
192 views

According to wave function collapse you only have one outcome, so what happens to the other superpositions?

If the superpositions of a wave function are not needed because only one of the superpositions is allowed, what happens to the eigenvalues of the "null" superpositions? Is the energy transferred ...
4
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2answers
308 views

Does a wavefunction interact with itself?

Considering the double slit experiment with a charged particle, after the particle passes through the slits, do the two portions of the wavefunctions feel the electromagnetic attraction of the other ...
5
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2answers
861 views

Does the Hilbert space of the universe have to be infinite dimensional to make sense of quantum mechanics?

Does the Hilbert space of the universe have to be infinite dimensional to make sense of quantum mechanics? Otherwise, decoherence can never become exact. Does interpreting quantum mechanics require ...
0
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2answers
102 views

Can the Lorentz force stabilize the Hydrogen atom?

I've recently been working on relative equilibria for some systems of particles. (ie. studying equilibrium solutions in a rotating frame. Saturn's rings for example.) This has evolved into some ...
1
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1answer
87 views

Mainstream view on the measurement problem

What is the modern mainstream way to deal with the measurement problem? For this question, the measurement problem is the problem of formalizing wave function collapse when the observer is part of the ...
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0answers
39 views

Books on foundations of QM [duplicate]

I am seeking for books on foundations of Quantum Mechanics with subjects like the EPR experiment, Bell's theorem, the problem of measurement, entanglement, decoherence, nonlocality, interpretations, ...
2
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5answers
380 views

Wave/particle duality

Apologies if this has been asked before (I did check and I believe it wasn't). I have a question about the particle/wave duality of photons (or other particles). Depending on what and how we measure ...
0
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0answers
16 views

Quantum observation in the double slit experiment? [duplicate]

As far as quantum observation, when a human observes electrons going through the double whole experiment, have scientist tried having a blind person observe the experiment to see if the electrons ...
2
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4answers
436 views

Double slit experiment and single particles. Is the wave function just a mathematical model?

I really do want to apologize in advance, I know this question has been 'answered' before. I have this 'problem' of feeling negatively toward much of today's 'mystical' interpretations of physics, ...
3
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1answer
106 views

Is there an absolute minimum scale to the universe? If so, why?

Based on my rather circumscribed understanding of modern physics, one of the key insights of quantum mechanics over previous scientific theories is the prediction that there exists an absolute limit ...
1
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4answers
200 views

Are there any non-interpretational arguments in favour of Everett's Many-Worlds?

As far as I understand Everett's Many-Worlds Interpretation, he makes the case for a realist theory of QM at the enormous cost of many-worlds. Are there any arguments in favour of Everett's ...
0
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2answers
339 views

How could the multiverse theory be disproven?

Theorists (physicists) suggest that there is the term/entity, the Multiverse that contains a huge number of universes not necessarily like our own. I personally find this theory very elegant because ...
2
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1answer
109 views

Decoherence in Everett quantum mechanics

Take an initial state and its environment, $E$, as follows, $$ |\psi\rangle_i = |0\rangle |E\rangle + \sqrt{2}|1\rangle |E\rangle. $$ Suppose that I've written it already in the basis in which the ...
4
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1answer
88 views

Is frequency or Bayesian interpretation used in quantum mechanics?

In quantum mechanics, we discussed about probability. There are two kinds of interpretations: frequency and Bayesian. Which one is actually used in quantum mechanics? My impression is, it doesn't ...
1
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1answer
157 views

Is it true that Macrorealism can be shown false?

http://en.wikipedia.org/wiki/Leggett-Garg_inequality As you can see by the link above, it claims that if the violation of the Leggett–Garg inequality can be demonstrated on the macroscopic scale, it ...
2
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2answers
109 views

Logic of the 'imaginary wave function collapse' argument in Double Slit experiment

My question is in regards to the stance that the 'wave function collapse' is not an actual physical occurrence. That is, you are not, by observation, changing the particles position from a wave to a ...
10
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1answer
513 views

Interpretations of quantum mechanics

It is well known that there are many interpretations of quantum mechanics. I'm wondering if there is a specific reason why the Copenhagen interpretation is the most popular. Why is it that the ...
10
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1answer
251 views

Can observers be particles?

Generally Quantum mechanics divides a system what is to be observed and an observer. This is generally taken to be some human being. But why restrict it to such? Why not a particle? Is there a good ...
4
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7answers
779 views

Which physically acceptable quantum interpretations do not require the existence of any observer at all?

Some interpretations of quantum mechanics — like the Copenhagen interpretation in particular — require the existence of an observer. The role of the observer is a bit mysterious. After ...
0
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6answers
249 views

Could this mean that Schrodinger's Cat thought experiment is false?

Since it is uncertain on whether or not the cat could be dead or alive, it is concluded that it depends on the observer to make it either dead or alive. But lets look at a clock. It doesn't take ...
0
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0answers
54 views

Quantum entanglement, principle of locality and speed of light

I know it's a newbie question but I was wondering about how the principle of locality and the speed of light's limit fit with the phenomena of quantum entanglement? I've read that, due to Bell's ...
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0answers
49 views

Could the space outside the observable universe be entangled?

The title really says it all. One follow-up question is: How could one falsify this?
7
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1answer
430 views

Box normalization

Whenever we study free fields, the solutions of these fields (or particles, whatever feels most comfortable) are always given by plane waves. The dispersion-relation $\omega=\omega(k)$ will of course ...
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2answers
158 views

Non-locality and Bell's theory

Non-Locality – (just ) one more question? I have read comments that Bell’s theory proves quantum mechanics is non-local, and also comments that it does not. I have read a comment by a very eminent ...
10
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2answers
262 views

Are quantum decoherence and Everettian approaches to the measurement problem necessarily distinct?

As I understand it, there is a large contingent of physicists who believe that the measurement problem is "solved" by decoherence, without, for example, needing to postulate the existence of "many ...
0
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0answers
37 views

Hamiltonian (temperature?) and frame of reference

So we can define a particle by defining its kinetic and potential energy, knowing that we can get a wavefunction describing a particle. But the kinetic energy involves motion, and motion can be ...
3
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2answers
176 views

Books about alternative interpretations of quantum mechanics

Recently I've heard that there exist alternative interpretations of quantum mechanics which, while not as widespread as the Copenhagen intepretation (or so it would seem), are equally valid in the ...
0
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0answers
35 views

Choices within the many-worlds interpretation

I should preface this question by pointing out that I am a completely amateur scientist and may be missing something very obvious. I've been learning about the many-worlds interpretation recently and ...
2
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4answers
245 views

Probability and the many-worlds interpretation

If I toss a coin, then according to the many worlds interpretation of QM, in half those worlds I'll get a head. If I then toss again, then in a quarter I will have got two heads. And so on. There will ...
4
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3answers
275 views

What's wrong with this faster-than-light gedankenexperiment?

It is common wisdom - and mathematically proven - that quantum entanglement cannot be used to bypass the relativistic speed limit and transfer information faster than light. So there must be something ...
2
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3answers
199 views

What happens with a tunneling particle when its momentum is imaginary in QM?

In classical mechanics the motion of a particle is bounded if it is trapped in a potential well. In quantum mechanics this is no longer the case and there is a non zero probability of the particle to ...
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2answers
84 views

Under what circumstances is observing a superposition possible?

According to Ian Stewart's 2013 Symmetry: A Very Short Introduction (pp. 119-120), Experiment and theory suggest that superposed states should not be observable as such; only individual ...
2
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0answers
211 views

“Consciousness causes collapse”-interpretation or free will excluded by quantum zeno effect? [closed]

This question is if the von Neumann–Wigner interpretation, aka "consciousness cause collapse" (see e.g. John von Neumann's 1932 book The Mathematical Foundations of Quantum Mechanics) is compatible ...
20
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6answers
3k views

Why is superdeterminism generally regarded as a joke? [closed]

Before anything, I'm sorry for being an outsider coming to opine about your field. This is almost always a stupid decision, but I do have a good justification for this case. I've been reading about ...
2
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1answer
768 views

Can silicon droplets bouncing on a vibrating surface be a model for Quantum Mechanics?

In this video on youtube it is claimed that silicon droplets bouncing on a vibrating surface show behaviour in analogy to particle/wave duality in Quantum Mechanics. Is this true? Did they ...
2
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3answers
217 views

Are there any QM effects where charged particles are not intimately involved?

Are there any QM effects that have been/could be measured from interactions involving non-charged particles? Elementary QM is all about the electron energy levels in the atom, photon - atom ...
12
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3answers
994 views

How much is quantum computation changing the interpretation of quantum theory, and, if at all, how?

At the beginning of quantum computation, David Deutsch made a strong claim that the Many Worlds interpretation of quantum theory was at the foundation of his ability to do what he did. There was a lot ...
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2answers
171 views

What are the practical applications of quantum foundations?

Many quantum foundation researchers keep emphasizing that For All Practical Purposes (FAPP), quantum foundations are irrelevant. They even invented an acronym for it! Does that mean that quantum ...
0
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1answer
43 views

Would QM be detectable in a all boson universe

If there was a universe with the same laws as this one, but there were only bosons in it, would QM 'do anything'? Would there be any QM effects - such as an energy level (but that would require ...
3
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2answers
304 views

Determinism loophole?

I was thinking about the question I posted yesterday, and I thought of a better way to ask it. I'm trying to figure out why QM necessitates "pure randomness". Assume you have a photon that has a ...
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1answer
118 views

Many worlds interpretation

I think many worlds interpretation is inconsistent with the EPR paradox. Quantum mechanics says that particles are really in more places at the same time and the particle is really only probability ...
7
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4answers
642 views

Quantum Wave Mechanics

I am studying QM-I these days. Now, I just think of the wave function as just a mathematical function that defines the state of the particle at an instant and from it you can extract various ...