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.

Filter by
Sorted by
Tagged with
0
votes
2answers
76 views

What is the definition of a 'branch' in the many-worlds interpretation (MWI) of quantum mechanics?

In my rudimentary understanding of the many-worlds interpretation of quantum mechanics, one posits the existence of a universal wave function - the state of the entire universe - wherein the various ...
1
vote
0answers
22 views

Why would the classical (local) correlation in Bell's experiment rule out the cosine of the angle?

This question expands on a specific detail of this previous question: Why would classical correlation in Bell's experiment be a linear function of angle? I would have commented on/answered that ...
-1
votes
1answer
40 views

Does the Many worlds interpretation of quantum mechanics imply the existence of all conceivable worlds? [closed]

what I mean by this is, does every universe conceivable exist? would any universe i think of exist? could there be a universe of nothingness? are there universes of TV shows? are there universes with ...
-1
votes
0answers
45 views

Is the quantum vacuum common across the many-worlds?

I don't have the physics to elaborate on this in anything but a hand-waving manner, but this is my conjecture: In the MWI when the universe splits A/B at a collapse event, both A and B originated in ...
-1
votes
2answers
44 views

If you were a unentangled observer, would you see the correct state of Schrödinger's cat?

If you were able to peer into the box without opening it and without interacting with the wave function, I would think that you can see the true state of the cat. Therefore, I assume the cat is at a ...
0
votes
0answers
107 views

How to operationally realize the following type of equations of motion?

It is well known that for a free particle, described by $H=\hat{p}^2/2m$, $\hat{p}_{x}(t)=$ constant (similarly for other components of momentum). Meanwhile, $\hat{x}(t)$ is not a constant, being ...
36
votes
4answers
4k views

How does many worlds interpretation work for non-50/50 probabilities?

The many-worlds interpretation of quantum mechanics has always been explained to me at a high level using examples of binary events (e.g. atom either did or did not decay at any given moment in time), ...
1
vote
1answer
53 views

Doesn't the Many Worlds interpretation of Quantum Mechanics rail to remove randomness?

In the Copenhagen Interpretation, the observed state of a particle is random. In the Many Worlds interpretation, the all possible observed state of a particle are true, an the universe "splits". But ...
0
votes
1answer
52 views

What is a good technical book to start learning Many worlds interpretation?

Good books exist on quantum mechanics emphasizing on the Copenhagen Interpretation.What are some good "technical" books on Everettian Many world interpretation of quantum mechanics? I emphasize on the ...
0
votes
1answer
134 views

What happens to the Universe if a quantum coin in a black box is secretly flipped for zillions times?

First, let us using an IBM quantum processor (QP) to run the following simple quantum circuit: The IBM $U_3 (\pi/3,0,0) $ gate transforms the initial state $q[0] = \vert0\rangle$ to a biased quantum ...
1
vote
0answers
77 views

How does virtual photon exchange lead to the attraction of opposite charges?

This wonderful page in the physics FAQ, from 1994, by Matt McIrvin http://math.ucr.edu/home/baez/physics/Quantum/virtual_particles.html explains how the exchange of virtual photons leads to ...
0
votes
1answer
78 views

Everett's interpretation of QM - does the world actually branch, physically?

Under Everett's interpretation I understand the key notion is that every quantum possibility is physically realized in its own universe, such that any one universe only contains any one physical ...
0
votes
1answer
32 views

Does the many worlds interpretation require a 100% spin up branch?

In his Q&A after his Brief History of Quantum Mechanics talk Sean Caroll mentioned that when writing his book he made 50 quantum spin measurements for an example. He admitted that in some universe ...
1
vote
1answer
75 views

Is it possible to classify “branches” in the MWI of QM? [closed]

In Everett's Many Worlds Interpretation of QM, what would be classified as a "world" or a "branch"? Would the "reality" of what I'm consciously experiencing be distinguishable from a separate "...
1
vote
0answers
69 views

Many worlds & non-local correlation

I just finished Sean Carroll's Something Deeply Hidden, and found it the best explanation of MWI I've ever seen, and even find that I have no good arguments against it; the parts I understand seem ...
2
votes
1answer
84 views

Quantum probabilities or frequencies? Derivation or a postulate

The Born rule $$p=|\langle\psi|\phi\rangle|^2$$ defines the quantum probability and answers the question what is the probability that the measurement of $\psi$ will produce the outcome $\phi$? This ...
0
votes
0answers
15 views

Self-locating probabilities when one ceases to be an observer

I have heard (e.g. on Sean Carroll's podcast), that one way at arriving at the Born rule from an Everettian interpretation of quantum mechanics is by self-locating probabilties. If some outcome(s) ...
1
vote
0answers
50 views

De-Broglie Wavelength and the Pilot Wave Theory

I researched a lot of questions on De-Broglie waves on this website and discovered a dense fog of confusion amongst everyone. Louis De-Broglie proposed "Matter Waves" and a simple equation describing ...
0
votes
1answer
42 views

Can two observers on different components of the wave function, interact gravitationally?

In a semiclassical gravity theory, the Einstein tensor is proportional to the expected value of the energy-momentum operator on a state. Now if the state is a combination of two eigenstates, each one ...
1
vote
3answers
115 views

How does disregarding realism but maintaining locality explain the Bell Experiment?

If we conduct a simple Bell experiment, we can show that "hidden attributes" are inconsistent with the probabilisitic distribution of results that we get in an Alice/Bob type game played with ...
0
votes
1answer
57 views

What interpretation of quantum mechanics do Conditional Probabilities feature in and how is it different from the Many-worlds Interpretation?

Please edit out the link if it is not allowed, but on page 249 of Griffiths's Consistent Quantum Theory, he makes a decision to abandon wavefunction collapse and instead use conditional states, ...
1
vote
0answers
63 views

Bohmian vs Copenhagen Interpretation

Is there any experiment that could settle the debate between De Broglie - Bohm Pilot Wave Theory and the Copenhagen Interpretation?
0
votes
1answer
80 views

Interpretation of the quantum field in light of the interpretation of propagators

In Page 38 of David Tong's QFT notes and Page 27 (Chapter 2.4 The Klein-Gordon Field in Space-Time under the heading Causality) of Peskin and Schroeder's Introduction to Quantum Field Theory, the ...
2
votes
1answer
94 views

Does exist a (truly) stochastic but causal physical process?

I wonder if it is possible for causality to be held, but not determinism. Does any real-world example exist? If yes, please explain how does that satisfy causality and not determinism. (for example, ...
-5
votes
2answers
124 views

I could prove that Copenhagen QM and causality are incompatible; is it right? [closed]

A quantum system consists of some states. It is in all of the states but beCAUSE of the act of the measurement, the wavefunction collapses into one state. I am really confused because I can repeat the ...
0
votes
1answer
48 views

What is von Neumann's branching of possible worlds?

In the Many Worlds Interpretation's wikipedia article (https://en.wikipedia.org/wiki/Many-worlds_interpretation), it says, at the "Reception" part: "(...) On the other hand, the same derogatory ...
1
vote
2answers
125 views

Isn't causality a disproof for the Copenhagen interpretation [duplicate]

In QM, each measurement result cannot be predicted, in other words, that is random. This being random has a great implication: if there is no rule to specify the results, so there is cause. This lack ...
0
votes
0answers
53 views

What is the interpretation physics of the below integral which represented in terms of plasma dispersion function?

I am not a physicist and am not familiar with Plasma physics, I have tried to evaluate some special function related to Plasma dispersion function like error function I come up to the below integral ...
0
votes
3answers
95 views

Why is future 'deterministic' but not the past?

From what I saw, it seems that if theoretically you know the current states of a system (which seems impossible), you can predict its future wave function. But since there are wave function collapses, ...
2
votes
1answer
59 views

Could there be any situation where two noncommuting observables are simultaneously considered?

As physicist Robert Griffiths (one of the founders of the 'Consistent Histories' formalism) says: "Two physical variables whose operators do not commute correspond to incompatible sample spaces, and ...
1
vote
1answer
58 views

Decoherence Tutorial on level of the Theoretical Minimum books

I'm trying to understand decoherence and other issues in QM related to the Everettian interpretation. I have a BS in physics, but that was 37 years ago. I've read Susskind and Friedman's book, The ...
1
vote
0answers
12 views

Difference between multiphoton signal and, $n$-photon signal state

I was reading decoy state quantum key distribution article, by Lo et.al. (PRL paper , PRA paper). In this article, authors have discussed the possibility of photon number splitting attack due to ...
-1
votes
4answers
83 views

In QM, what causes a particle to have more probability to be somewhere else when it's found in a less probable position?

For the position of a particle, there's a probability which, somewhere, there's highest probability. And as you move away from it, the probability reduces. But the particle can be anywhere. It's often ...
-3
votes
1answer
83 views

Does the anthropic principle rule out the many worlds interpretation of quantum mechanics?

TAP says that the set of observations of things we have is not a random set of all things; there is observer bias. TMWI of QM says that the universe splits to accommodate every possible collapse ...
-1
votes
2answers
115 views

What is the whole idea behind retrocausality in quantum mechanics?

I want to see if any of the alternative theories/interpretations of QM have any merit to them(Pilot wave, superdeterminism, etc). I think the motivations behind these theories include(I don't think ...
0
votes
0answers
28 views

Many Worlds Interpretation and Quantum Key Distribution / Quantum Computing

I'm trying to understand how to interpret Quantum Key Distribution and Quantum Computing in terms of the Many Worlds Interpretation of Quantum Mechanics. So according to the many worlds ...
-9
votes
3answers
132 views

Isn't the uncertainty principle a circular argument? [closed]

The uncertainty principle says that uncertainty must be greater than or equal to some value. That's the same as saying if uncertainty exists, it exists. $$\Delta x\Delta p\geq\frac{\hbar}{2}$$ If ...
1
vote
1answer
57 views

How is many worlds different to basic probabilities?

In the many worlds theory the universes branch according to the wave function. We find ourselves travelling down one path of an immense number of these branches of a tree. When we branch, we have no ...
0
votes
0answers
24 views

Spatial dimensions in Many-Worlds interpretation?

As I understand it, in the many worlds interpretation there is only the wavefunction evolving in Hilbert space, and each non-interacting part of this configuration space experiences itself as a ...
0
votes
1answer
63 views

Where do the “branches” of the wavefunction come from?

In the many worlds interpretation there is only supposed to be the wavefunction and no collapse, which puts an image in my mind of this thing waving in 3D space sort of like temperature fluctuations ...
2
votes
0answers
46 views

Photon Wave Function in Position Space

Last year I did some research on the possibility of defining a PWF ( photon wave function) however there are many things that I haven't understood since then. So I want to ask what are your toughts on ...
1
vote
0answers
37 views

In the many worlds interpretation, where does the energy come from to create branching universes? [duplicate]

In the many worlds interpretation, where does the energy come from to 'create' the new universes at all the branching points? Is it being taken from some infinitely energy-replete background universe? ...
-1
votes
1answer
52 views

If a choice is made, will it create a singularity? [closed]

When I watched videos of a TV show named "Star vs the forces of evil" on Youtube, there was a video about the main character - Star - being forced to solve a Math problem, because all versions of Star ...
0
votes
1answer
49 views

Could different outcomes have different physics in Wigner's friend?

Could different outcomes have different physics in Wigner's friend? Physicist Eugene Wigner said that consciousness was fundamental for physics and that laws of physics existed because of it. He said ...
0
votes
1answer
73 views

Isn’t the Many-World interpretation improbable?

The Many-Worlds interpretation is possible when the event at issue has a 50-50 probability. It becomes suspect when the probability of an event is not 50-50. The prime example is experiments with ...
-2
votes
1answer
75 views

Realtivity and the measurement problem

If a quantum system is prepared and the eigenvalues are known but the experimenter gets in a spaceship and rockets off in a particular direction at relativistic speeds and then performs the ...
0
votes
0answers
38 views

The Many Worlds Interpretation and the Double Slit Experiment [duplicate]

In the double slit experiment one wave function passing through the slits is enough to produce a photon on each detector in the many worlds. How does a single wave function produce so many photons?
1
vote
0answers
49 views

ER=EPR, Entanglement and Subjectivity

ER=EPR refers to a conjectured connection between entanglement and Einstein-Rosen bridges. Consider the quantum teleportation circuit, where Alice ($A$) and Bob ($B$) make use of an entangled pair of ...
0
votes
4answers
86 views

Can the Many Worlds Interpretation of Quantum mechanics, in principle, cater for all physical process from smallest to largest “systems”

I am writing to check I have my understanding of the MWI interpretation / theory of QM correct, inspired by an article in Stanford Encyclopedia of Philosophy, "The Many-Worlds Interpretation" - see: ...
5
votes
8answers
318 views

How do “many worlds” theorists explain particle double-slit interference patterns?

In the past couple of weeks I’ve re-watched Sidney Coleman’s wonderful 1994 lecture “Quantum Mechanics” in Your Face” and Sean Carroll’s 2019 Google talk “Something Deeply Hidden: Quantum Worlds & ...

1
2 3 4 5
15