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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Does information paradox in the Many Worlds interpretation cause a problem? [closed]

I'm taking a philosophy of time travel class. In one of the lectures, the teacher was discussing problems with the Many Worlds interpretation. He talked about how since anything that can possibly ...
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3answers
163 views

EPR Paradox resolution: the spin is fixed at creation but its measurement isn't?

The Wikipedia article on the EPR paradox uses the example of an electron and positron created from a common source, each moving in an opposite direction to the other. Detector A is used to measure the ...
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1answer
184 views

Do consciousnesses get “scattered” across the many worlds of the MWI?

According the many worlds-interpretation (MWI) of quantum mechanics, following a decision with possible outcomes $A$ and $B$, with respective probabilities $p_A=P(A)$ and $p_B=P(B)$, a proportion ...
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2answers
176 views

Quasiparticles in Bohmian mechanics

My questions are about de Broglie-Bohm "pilot wave" interpretation of quantum mechanics (a.k.a. Bohmian mechanics). Do quasiparticles have any meaning in Bohmian mechanics, or not? Specifically, is ...
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1answer
207 views

Why should multiple versions of a weak measurement preclude it from being a measurement of intrinsic properties of some system

I've been trying to understand Stephen Parrott's criticisms of weak measurement, outlined most concisely here: http://arxiv.org/abs/0909.0295 One of his major criticisms is that weak measurement is ...
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6answers
220 views

Meaning of probability in a multiverse/a many-world interpretation?

Consider me tossing a coin and I got tail as a result on observing it. Then, what would be the result of the 'parallel me' in another universe? If the 'parallel me' gets head as a result then, ...
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4answers
569 views

What is an interpretation of quantum mechanics?

In the sense of "Copenhagen Interpretation", what exactly is an interpretation? What purpose does an interpretation serve? Can an interpretation be tested or even be correct or incorrect independent ...
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1answer
166 views

Why no Top Physicists Work on Bohmian Mechanics? [duplicate]

I'm curious to hear some opinions from serious physicists on this site as to why no top physicists have ever worked on Bohmian Mechanics. Except Bohm and Bell, the theory has received virtually no ...
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1answer
127 views

Argument for proving that the universe must be indeterministic [duplicate]

Can there exist an argument that could be used for proving that the universe is indeterministic? If this one seems to be too strict (rigorous), I would also be interested to know a 1-sentence ...
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2answers
3k views

What is wrong with the De Broglie–Bohm theory a.k.a “Causal Interpretation” of quantum theory? [duplicate]

Possible Duplicate: Why do people still talk about bohmian mechanics/hidden variables I've heard of De Broglie–Bohm theory a.k.a causal interpretation of quantum theory. The predictions ...
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1answer
171 views

What obstacles does de Broglie's pilot theory have to overcome? [duplicate]

I have been reading through a Wired article on pilot wave theory which talks about new evidence in support of Louis de Broglie's concept of pilot theory through experiments showing that the droplet in ...
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3answers
186 views

Why does the Copenhagen interpretation assert randomness if this cannot be tested?

Why does the Copenhagen interpretation of QM assert that random events occur if such a claim cannot ever be proven or disproven? A related question: How to tell if QM is really random? Edit On ...
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1answer
914 views

What is the meaning of the Fourier transform of Feynman propagator?

I know $K(a,b,t)$ is the probability amplitude that a particle that starts at point $a$ is found at point $b$ at a time $t$ later. There is also an expression that sometimes is called green function: ...
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0answers
63 views

Many Worlds or Infinite Worlds?

Looking at the latest paper to deal with the topic: where it purports to show that QM can be recovered from the interactions of a multitude of Newtonian worlds, we have the following statements: ...
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0answers
86 views

I don't get the concept of “God plays with dice” - In what scenario is it proven that he does? [duplicate]

Does God Play With Dice? by Stephen Hawking I am no physicists, but I don't get the concept of God playing with dice. Logic shows me that the entire universe is calculated very precisely according ...
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0answers
38 views

How would the transactional interpretation “bootstrap”

I have an interest in quantum physics and have been trying to educate myself here, other places on line and by reading "The Quantum Universe". During this process I became quite drawn to the ...
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0answers
69 views

Bell's inequality

For a project, I'm planning to study Bell's inequality, which as far as I can gather is taken to rule out hidden variable theories of QM. I'm looking for recommendations of decent sources which derive ...
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2answers
2k views

If the moon is not there when no one is looking, how does the moon know how to stay in orbit between observations?

Quantum Copenhagenists will tell you if there is a stop sign, it only manifests itself by the act of observation. When no one is looking, there is nothing there. This is like the cognitive process of ...
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2answers
491 views

What's wrong with this experiment showing that either FTL communication is possible or complementarity doesn't hold?

The assumptions are: Alice and Bob have perfectly synchronized clocks Alice and Bob have successfully exchanged a pair of entangled photons The idea is simply to have Alice and Bob perform the ...
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3answers
320 views

A question on quantum computing and de Broglie's pilot wave theory

I don't know much about quantum computing except what I have read about on wiki and popsci. I have been reading about the de Broglie-Bohm pilot wave theory and how they describe quantum mechanics in ...
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3answers
214 views

Does processing for a quantum computer take place in other universes?

Apologies in advance if my question seems misinformed. I am a software developer, and neither quantum mechanics nor physics are my specialties. From ...
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3answers
204 views

What is the best article presenting counterarguments to a many-world interpretation? [duplicate]

I'd like to see a clear overview of why the many-world interpretation (WWI) of quantum is wrong, written by someone who believes that. This would be aimed at a technically aware audience, yet as an ...
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1answer
425 views

If there is no collapse of the wave-function does this mean that the many worlds interpretation of QM must be wrong?

If as some people suggest, there is no collapse of the wave function (is there a standard name for this position), then must one rule out the many-worlds interpretation of QM?
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9answers
1k views

What criteria distinguishes causality from retrocausality?

The brilliant philosopher David Hume remarked that if two events are always found to be correlated to each other with one event happening prior to the other, we call the earlier event the cause and ...
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0answers
20 views

A question on quantum computing? [duplicate]

I dont know much about quantum computing except what i have read about on wiki and popsci. I have been reading about the de broglie-bohm pilot wave theory and how they describe quantum mechanics in ...
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2answers
164 views

Copenhagen interpretation

Reading some science history, Werner Heisenberg and Bohr created the Copenhagen interpretation, but what I didn't get is how can we connect this interpretation to Schroedinger's cat and the double ...
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4answers
542 views

Quantum mechanics threshold

First of all I beg your forgiveness as I am not a physicist and the question I am going to ask may sound silly. I am aware that beyond a certain threshold in the hierarchy of building blocks of ...
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4answers
2k views

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 ...
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3answers
250 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 ...
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3answers
228 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 ...
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1answer
74 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
53 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 ...
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0answers
388 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 ...
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3answers
208 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 ...
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2answers
367 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 ...
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2answers
1k 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 ...
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2answers
166 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 ...
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1answer
109 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
42 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, ...
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5answers
426 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 ...
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4answers
642 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, ...
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1answer
146 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 ...
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4answers
210 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 ...
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2answers
591 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 ...
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1answer
136 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 ...
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0answers
121 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 ...
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1answer
201 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 ...
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2answers
156 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 ...
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1answer
557 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 ...
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1answer
270 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 ...