Questions tagged [quantum-interpretations]

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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How to analyze observer and event

I've got off with a heated debate about the fundamentality of either the observer or the event, with no clear answer as to what really will matter in the end. I am an immature in quantum theory, and ...
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Does Quantum Darwinism select against the Frauchiger-Renner inconsistent states?

Zurek's Quantum Darwinism is based on an environment induced superselection of pointer states, within which entanglement plays an essential role. Similar arguments can be made related to Horodecki's ...
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Does the Copenhagen interpretation (+ “quasi-classical apparatus”) allow one to bypass a derivation's objection? [on hold]

Background I asked this question, where I'm thinking about this joshphysics's answer: And the gist of what I get is (from the answers and the chatroom) within interpretations of quantum mechanics ...
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Is Quantum Darwinism considered an interpretation of Quantum Mechanics?

I did not see Quantum Darwinism in the Wikipedia article on the interpretations of Quantum Mechanics but there is a Wikipedia article on Quantum Darwinism so this prompted my question. As for example ...
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Noether's Theorem and the Measurement? (In Copenhagen)

Background I'm trying to recently understand the Copenhagen interpretation. We all know due to Noether's theorem energy is translational invariance in time. However, in quantum mechanics the ...
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Why is the application of probability in QM fundamentally different from application of probability in other areas?

Why is the application of probability in quantum mechanics (QM) fundamentally different from its application in other areas? QM applies probability according to the same probability axioms as in other ...
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How many worlds are there during branching in the many worlds interpretation?

Background and Question "Measurements are modelled as interactions between subsystems of the universe and manifest themselves as a branching of the universal state." - Wikipedia What is the ...
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Wigner's Friend in the many worlds?

Background In the thought experiment of Wigner's friend the many-worlders claim: "Everett claims to solve the Wigner's Friend paradox by only allowing a continuous unitary time evolution of the wave ...
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What is the physical meaning of the sum of two non-commuting observables?

Scenario: ${\mathcal A}$ and ${\mathcal B}$ are two observables. Mathematically we model them by two Hermitian operators $A\colon H \to H$ and $B\colon H \to H$ on a separable Hilbert space. ...
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Why can't GRW theory be easily tested?

To me it seems that no matter if GRW theory is true, there would already be a lot of observations and evidence for/against it, since it will in quite simple situations make different predictions from ...
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1answer
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Physical meaning of whole state space for spin-one

The spin-one quantum states belong to $\mathbb{C}^3$, with a set of orthonormal bases taken as the spin component along a direction, which would correspond to the direction of the magnetic fild ...
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Is this interpretation of the Copenhagen Interpretation accurate in this book from Bruce Rosenblum and Fred Kuttner?

I'm very new on this particular subject, can anyone help me determine how accurate the interpretation of Bohr's quote is, and where is the origin of this quote?
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Could Schrödinger's universes have different fundamental laws?

It seems that Erwin Schrödinger was one of the first proponents of a multiverse concept. In Dublin in 1952, Erwin Schrödinger gave a lecture in which he said that when his equations seemed to ...
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Is the trajectory of a quantum particle a well defined concept and how does this depend on the interpretation of quantum mechanics?

A common statement about quantum physics is that the "trajectory" of a particle is no longer a well defined concept because of the uncertainty relations for position and momentum. If one interprets ...
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Does the quantum eraser double slit experiment disprove many worlds interpretation?

The quantum eraser double slit experiment shows that interference pattern is destroyed not by interacting with the quantum particle, but rather by getting which path information. In this experiment ...
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Don't these experiments suggest that locality has to be abandoned in the quantum realm?

First a quick recap because maybe my understanding/assumptions are flawed (you can jump to the question highlighted in bold below if you like to): Bell's inequalities require that an accurate(ly ...
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Topos quantum theory and distributive logic

I am reading an introductory review on topos quantum theory https://arxiv.org/abs/1106.5660 where in the motivation part it says (emphasis is mine): As we can see the non realism of standard ...
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Can unitary probability theory (quantum mechanics) emerge from a lack of information about a deterministic process? [duplicate]

My initial question below appears to be unclear so I am rewording in more succinctly here. The pre-edit question remains below. There exists two types of probability theory: 1-norm (classic ...
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What generates physical meaning in mathematical quantum theory?

Let mathematical quantum theories be theories of Hilbert-space rays together with probability / amplitude / unitary evolution / Hermitian operator machineries. Observations essentially correspond to ...
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Einselection locality in decoherence theory

Consider two polarity-wise entangled photons A and B in an EPR experiment. The process of measuring the polarization of photon A by Alice is described by the decoherence of the 2-photons system ...
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What's the difference between the Copenhagen and many-worlds interpretations?

I don't know that much about quantum mechanics, but after reading the Wikipedia pages for the Copenhagen and many-worlds interpretations, I'm left with the impression that the two are describing the ...
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Why do we see particles in the many-worlds interpretation?

I am starting to feel like I have a decent grasp on the MWI, but a piece of it keeps bugging me. My understanding is that quantum objects are kind of spread out and wavy until something comes along ...
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Is There Already Evidence Supporting Stapp's Theory of the Causally Efficacious Human Will? [closed]

Physicists J. Acacio de Barros and Gary Oas wrote a paper titled “Can we Falsify the Consciousness-Causes-Collapse Hypothesis in Quantum Mechanics?” published in the Foundations of Physics, 47(10):...
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Why does MWI need decoherence theory and how can these models be combined?

As far as I understood decoherence theory, it explains, why we are not able to measure superposition of macroscopic objects in some specific basis, which turns out to be the position-basis in most ...
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What is the interpretation of complex amplitudes in the many-worlds interpretation? [closed]

Many (popular?) accounts of MWI seems to suggest that MWI "solves everything" (including collapse), as long as you accept the infinitely branching (and co-existing) universes, etc. But I don't fully ...
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Did Wheeler propose some kind of variation of MWI where universes would have different laws of physics?

John Wheeler proposed along with Hugh Everett and Bryce DeWitt the 'Many Worlds' Interpretation of Quantum Mechanics (although he expressed some doubts about its validity) I have read, from an ...
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Are different interpretations of quantum mechanics empirically distinguishable?

Are the different interpretations of Quantum mechanics just different viewpoints of the same physical reality? Or can experiments distinguish them? Are they empirically distinguishable or not? I have ...
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Where to draw the line between quantum mechanics theory and its interpretation(s)?

I've completed a full year QM course (undergraduate level) and I am left confused on where to draw the line between quantum mechanics theory and its interpretation(s). I would personally like to stick ...
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How is it possible that consciousness-causes-collapse interpretations of QM are not falsified by the Quantum Zeno effect? [closed]

As I understand it, consciousness-causes-collapse (CCC) theories, although not very popular among physicists, have not been falsified (e.g. https://arxiv.org/abs/1609.00614). This confuses me ...
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How Many Branches Does MWI Postulate?

I'm a little unclear on what the Many Worlds Interpretation (or family of interpretations), MWI, says will happen instead of a collapse. Suppose I measure particle spin on the X-axis. The Copenhagen ...
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166 views

Does Bell's theorem imply nonlocality using a false assumption? [closed]

In https://arxiv.org/abs/1409.5158, the author concludes that Bell tests cannot refute local realism, because they employ a wrong analysis. He says: "The quantum joint prediction cannot be ...
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If the wavefunction is continuous how can the many-worlds be discrete?

Preamble for clarity: The many worlds interpretation is usually used to explain the measurement of a 2 level system ($|0\rangle$ or $|1\rangle$) as: $$\frac{1}{\sqrt{2}}(|0\rangle+|1\rangle)|\text{...
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Many-worlds: Where does the energy come from?

With regard to the theory that each time a wave function collapses the universe splits so that each possible outcome really exists - where does all the energy required to create all the new universes ...
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Is the Second Law a consequence of the Many Worlds principle?

I've done a bit of browsing on this subject, and haven't found any papers that directly address this question. Here's the idea: In the Many Worlds View (MWV), there is no loss of information from ...
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Are longer lives more likely in Everettian multiverse?

There are some interesting statistical thought experiments related to observers and the Anthropic Principle such as the Doomsday Argument formulated by a physicist Brandon Carter and later improved by ...
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Does the Uncertainty Principle really rule out the existence of definite trajectory of electrons?

Excerpt from my textbook It is impossible to determine simultaneously, the exact position and exact momentum (or velocity) of an electron. It rules out the existence of definite trajectories ...
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Should it be obvious that independent quantum states are composed by taking the tensor product?

My text introduces multi-quibt quantum states with the example of a state that can be "factored" into two (non-entangled) substates. It then goes on to suggest that it should be obvious1 that the ...
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Universal wave function

Doesn't the existence of a Universal wave function allow one to extract a preferred space time foliation? There are plenty of papers that try and derive the preferred space time foliation from BM ...
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Why doesn't Wigner's friend interact with the system?

So I was recently modelling something that turned out to be basically Wigner's friend. I saw there were some differences (in the Wiki page) in how it was modelled: Namely, that Wigner's friend ...
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Change of basis in the many worlds interpretation?

Say we have two orthogonal states $|A\rangle$ and $|B\rangle$. In the many worlds interpretation, we can imagine two parallel universes in which we are either in state $A$ or $B$. But now if we ...
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Is the universe fundamentally deterministic?

I'm not sure if this is the right place to ask this question. I realise that this maybe a borderline philosophical question at this point in time, therefore feel free to close this question if you ...
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Why is wave-function collapse still being taught in quantum mechanics? [closed]

I don't really understand why wave-function collapse is still being taught while we seem to have better interpretations of QM available nowadays. During the early development of quantum mechanics the ...
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What are the (philosophical) implications (if any) of this experiment in relation to the Bohr-Einstein debates and hidden variable theories? [duplicate]

What are the (philosophical) implications  (if any ) of this experimental result, in relation to the Bohr - Einstein debates and hidden variable theories of quantum mechanics? A related question ...
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Is the collapse of the wave function inherently time asymmetric?

Schroedinger's equation, as we all know, is time symmetric. In quantum field theory, we have to come up with a more sophisticated CPT reversal, but the essential point remains unchanged. However, the ...
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Why do atoms interact differently? [closed]

We live in a 3-dimensional Universe, so why don't atoms (electrons) follow the same rules as humans, planets and other 3-dimensional objects? So does that mean electrons and other quantum objects pop ...
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Is the MWI symmetric in time?

Reading the blog of Sean Carroll (I recognize he isn't the only voice) has made me more sympathetic to the notion of many worlds, but reading Susskind (also not the only voice) has made me think that ...
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Why does the effect of measuring an entangled particle is not apparent when examining only one particle? [closed]

As far as I understand, the Bell test experiments show that observations (measurements) of entangled particles have an effect on one another. This effect is apparent when examining the results of ...
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What counts as a measurement?

In quantum mechanics, an elementary particle does not have a well defined position until a measurement is performed on it (right?). Such a "measurement" is any sort of interaction with other ...
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Is the Copenhagen interpretation falsifiable?

According to the Copenhagen interpretation, physical systems generally do not have definite properties prior to being measured. The Schrödinger's cat is both dead and alive, until an observation is ...
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Probability of finding a particle in a superposition

In QM, is it possible to ask what the probability of finding a particle in a superposition will be? Once a particle is in a superposition, it is possible to find out the probability that it will be ...