The quantum-interpretations tag has no wiki summary.
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Consequences of the new theorem in QM?
It seems there is a new theorem that changes the rules of the game in the interpretational debate on QM:
http://www.nature.com/news/quantum-theorem-shakes-foundations-1.9392
Does this only leave ...
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Why do people rule out local hidden variables?
I bet the automatic response to my question would be "Bells Theorem" and of course I am not disputing Bells proof, I am however uncertain of one of his assumptions.
The so called "no conspiracy" ...
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Why do people still talk about bohmian mechanics/hidden variables [closed]
I was reading the Feynman lectures in physics and after thinking about it for a while it seems particularly unreasonable to talk about hidden variables. Let us say that the electron has some internal ...
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On the nature of the collapse of the wave function
The collapse of the wave function by measurements is one of the most mysterious properties of quantum mechanics.
At what scale does the wave function collapse? What are the conditions for a ...
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The transactional interpretation of quantum mechanics
John Cramer’s transactional interpretation of quantum mechanics (TIQM) is billed as resolving the fuzzy agnosticism of the Copenhagen interpretation while avoiding the alleged ontological excesses of ...
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Will Determinism be ever possible?
What are the main problems that we need to solve to prove Laplace's determinism correct and overcome the Uncertainty principle?
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How isolated must a system be for it's wave function to be considered not collapsed?
As an undergrad I was often confused over people's bafflement with Schodinger's cat thought experiment. It seemed obvious to me that the term "observation" referred to the Geiger counter, not the ...
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796 views
What combinations of realism, non-locality, and contextuality are ruled out in quantum theory?
Bell's inequality theorem, along with experimental evidence, shows that we cannot have both realism and locality. While I don't fully understand it, Leggett's inequality takes this a step further and ...
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Can quantum mechanics really be the same as underlying deterministic theory?
I am perplexed by recent papers by 't Hooft giving an explicit construction for an underlying deterministic theory based on integers that is indistinguishable from quantum mechanics at experimentally ...
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Maxim Raykin's “solution to the measurement problem” using infinitely many derivatives
Recently I was made aware of the following arXiv preprint by Maxim Raykin: Analytical Quantum Dynamics in Infinite Phase Space. As far as I understand it, Raykin's idea is to reinterpret quantum ...
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Information conservation during quantum measurement
Consider the following experiment. I take a spin-$\frac{1}{2}$ particle and make a $\sigma_x$ measurement (measure the spin in the $x$ direction), then make a $\sigma_y$ measurement, then another ...
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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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How does Bell's theorem rule out the possibility of local hidden variables?
It seems to be common consensus that the world is non-deterministic and this is proved by Bell's theorem.
But even though Bell's experiments proved that the theory of quantum mechanics work, How does ...
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Is the wave function objective or subjective?
Here is a question I am curious about.
Is the wave function objective or subjective, or is such a question meaningless?
Conventionally, subjectivity is as follows: if a quantity is subjective then ...
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EPR-type experiments and faster-than-light communication using interference effects as signaling mechanism
I understand that faster-than-light communication is impossible when making single measurements, because the outcome of each measurement is random. However, shouldn't measurement on one side collapse ...
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1answer
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The System and the Measuring Gadget
In Quantum Mechanics the value of an observable results from the interaction between the "system" with the "Measuring gadget".
But when the experimenter[or the technologist concerned] is ...
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Is the “consistent histories” interpretation of QM a “many worlds interpretation” in disguise?
The so called consistent histories interpretation is claimed to be a correction of the Copenhagen Interpretation. One of its aim, as much as I can see is to show that observers don't have any special ...
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Is QFT mathematically self-consistent?
After recently going through a short program of self-study in quantum mechanics, I was surprised to find a quote attributed to Feynman essentially saying he was extremely bothered by the computational ...
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Is the quantum analog of a probability distribution the wave function or the density matrix?
Classically, probability distributions are nonnegative real measures over the space of all possible outcomes which add up to 1. What they mean is open to debate between Bayesians, frequentists and ...
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Why Quantum Mechanics as a non-fundamental effective theory?
My question: What (physical or mathematical) reasons (not philosophical) do some physicists ('t Hooft, Penrose, Smolin,...) argue/have in order to think that Quantum Mechanics could be substituted by ...
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Given entanglement, why is it permissible to consider the quantum state of subsystems?
Quantum entanglement is the norm, is it not? All that exists in reality is the wave function of the whole universe, true? So how come we can blithely talk about the quantum state of subsystems if ...
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Are many-worlds and the multiverse really the same thing?
Are many-worlds and the multiverse really the same thing?
Not too long ago, Susskind and Bousso uploaded the article "The Multiverse Interpretation of Quantum Mechanics" with the thesis that the ...
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Is quantum entanglement an objective or subjective property?
Imagine the following gedankenexperiment. Observer Alice is right here on Earth. Observer Bob is at say Alpha Centauri. A pair of maximally entangled qubits is formed with one qubit handed over to ...
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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 ...
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The measure problem in the anthropic principle
The anthropic principle is based upon Bayesian reasoning applied to the ensemble of universes, or parts thereof, conditioned upon the existence of conscious observers. That still leaves us with the ...
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What is the physical meaning of weak expectation values?
In the two-state formalism of Yakir Aharanov, the weak expectation value of an operator $A$ is $\frac{\langle \chi | A | \psi \rangle}{\langle \chi | \psi \rangle}$. This can have bizarre properties. ...
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Is it possible to define a “it went through two slits” observable?
This concerns the famous two-slit experiment. Electrons or photons or your favorite particle, doesn't matter. As we all know, the attempt to detect which slit the quanta pass through leads to loss ...
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Is contextuality required in quantum mechanics?
I still don't really understand what contextuality means in reference to quantum mechanics. If someone could give a clear definition that would be great. It sounds like it means you can't always ...
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Wigner's friend and intersubjectivity in quantum mechanics
Suppose there's a radioactive material and a 1/2 quantum probability of detecting it by a Geiger counter. This puts the system in a superposition. Also suppose you are in the same room, and the walls ...
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How do we know that there isn't a classical solution to the measurement problem/Quantum Mechanical uncertainty?
It was mentioned to me that it can be shown that there is no classical explanation for the uncertainty in Quantum Mechanics -- i.e. that there are no hidden workings that we have just not yet seen, ...
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4answers
258 views
Why should the observed probability distributions in quantum mechanics always align with the pointer basis of decoherence?
It has always been claimed decoherence solves the problem of the preferred-basis for observed probability distributions, but why should this be the case? If there is only one world, and there are ...
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2answers
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Are probability-preserving variations of QT with respect to the Born rule mathematically possible?
Is it possible to create (m)any theoretically workable framework(s) - that do(es) produce probabilities - by taking QM and replacing the Born(-like) rule(s) with something that is not equivalent to it ...
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215 views
How do we know particles exist? Aren't they just waves?
In the book "A Briefer History of Time" Stephen Hawking wrote:
The unpredictable, random element comes in only when we try to
interpret the wave in terms of the positions and velocities of
...
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Why is the tunnel effect of solid matter not observable in macroscopic objects?
Assume I place a tea cup on a table (say, about a centimetre thick). Quantum mechanics tells us that the wave function for the nuclei and electrons of the cup is not zero below the table (while being ...
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Hardy's Theorem
https://perimeterinstitute.ca/psi_portal/sites/perimeterinstitute.ca.psi_portal/files/hardyphysrevlett.68.2981.pdf
Some researchers in Bohmian Mechanics have hoped to make the theory Lorentz ...
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Consciousness and quantum mechanics [closed]
Quantum mechanics is very mysterious. Consciousness is often brought into play to explain quantum phenomena. Is this only a matter of convenience, or is consciousness inherent to interpreting quantum ...
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't Hooft for laypersons
I have looked at some of 't Hooft's recent papers and, unfortunately, they are well beyond my current level of comprehension. The same holds for the discussions that took place on this website. (See, ...
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Shor's algorithm and Bohmian Mechanics
Do quantum computer's tell us anything about the foundations of quantum theory? In particular Shor argued in the famous thread by 't Hooft
Why do people categorically dismiss some simple quantum ...
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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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Schrodinger's cat experiment
What's wrong in taking the cat as an observer in Schrodinger's experiment? Plz kindly elaborate! And if possible also describe about possible logics if the question bears the answer No.
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Is the classical world an illusion?
In the paper
Zeh, H. D. The Wave Function: It or Bit? In Science and Ultimate Reality, eds. J.D. Barrow, P.C.W. Davies, and C.L. Harper Jr. (Cambridge University Press, 2004), pp. 103-120. ...
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Can superdeterminism resolve contextuality, entanglement and Shor's algorithm in quantum mechanics?
Superdeterminism is the idea that the apparent freedom for the choice of experimental apparatuses and their settings are nothing but an illusion. Contextuality is the dependence of the properties of a ...
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What is the splitting structure of a state in thermal equilibrium in MWI?
What is the splitting structure of a state in thermal equilibrium in the many worlds interpretation? This is a mixed state, but we can perform a purification of it by doubling the system and forming a ...
