It has been realized that the measurement problem in quantum mechanics is essentially the determinateexperience problem. The problem is to explain how the linear quantum dynamics can be compatible with the existence of our definite experience. This means that in order to finally solve the measurement problem it is necessary to analyze the observer who is physically in a superposition of brain states with definite measurement records. Indeed, such quantum observers exist in all main realistic solutions to the measurement problem, including Bohm’s theory, Everett’s theory, and even the dynamical collapse theories. Then, what does it feel like to be a quantum observer? Although these theories, as well as the bare theory, give their respective answers to this intriguing question, it is still unknown what the true answer is. It can be expected that the answer, once it has been obtained, will have significant implications for solving the measurement problem.
In parallel with the Physics of the Observer Program and RFP announced by FQXi, we will host an online Workshop on Quantum Observers from 9th January 2016 to 19th January 2016. The workshop will bring together leading experts in the field, and address the most pressing issues in understanding quantum observers and solving the measurement problem.
Based on the successful experience from First iWorkshop on the Meaning of the Wave Function, John Bell Workshop 2014 and Quantum Foundations Workshop 2015, this workshop will be also selforganized to a large extent. Every member may create a topic in the workshop forum on his own, which gives a concise introduction to his ideas to be discussed, and which also states the date and time of his twohour discussion. Then other members can leave comments beforehand or participate in the discussions by text chat in the forum in the twohour duration at the time.
The list of participants and the schedule of this workshop will be announced soon. Selected presentations in this workshop will be published in International Journal of Quantum Foundations.
Note: This is not a public workshop. Group content and activity will only be visible to members of the group, most of who are invited. If you would like to participate in the workshop, please log in or contact us.

Ken Wharton replied to the topic Does the psiepistemic view really solve the measurement problem? in the forum 2016 International Workshop on Quantum Observers 6 years ago
Thanks for this, Shan.
I’m worried you’re setting up a bit of a straw man version of psiepistemic models (you call it the “realist psiepistemic” view, an interesting choice of words). I’d be surprised if there were many (or any!) quantum foundations people who take such a view.
Specifically, you are ascribing the following logic to anyone…[Read more]

Mark Stuckey replied to the topic Does the psiepistemic view really solve the measurement problem? in the forum 2016 International Workshop on Quantum Observers 6 years ago
As Price & Wharton point out, once you consider QM to be giving 4D distributions in spacetime (Lagrangian schema), rather than timeevolved distributions in configuration space (Newtonian schema), mysteries like the MP are resolved trivially. This is a psiepistemic view.

Miroljub Dugic replied to the topic The End of the ManyWorlds? (or Could we save Everett’s interpretation) in the forum 2016 International Workshop on Quantum Observers 6 years ago
Hi Aurelien,
Nice post!
Regarding ontology of MWI, it appears that a preferred structure (partition into subsystems, including virtual subsystems) of the Universe is needed. Otherwise sufficiency of decoherence for defining “branches” and/or reality of “world branching” are at stake. More technically: there exist mutually irreducible,…[Read more]

Kelvin McQueen replied to the topic How to solve the structured tails problem of dynamical collapse theories? in the forum 2016 International Workshop on Quantum Observers 6 years ago
This is an interesting solution. A version of it is discussed in section 4.4. of “Four Tails Problems for Dynamical Collapse Theories”. There it is discussed in the context of the matterdensity interpretation of GRW (sometimes called “GRWm”). The “denser” brains are the ones with the experiences of measurement outcomes. Since high density is…[Read more]

Jiri Soucek started the topic The absolute and relative truth in quantum theory: the superposition principle in the forum 2016 International Workshop on Quantum Observers 6 years ago
Using concepts of the absolute and relative truth in quantum mechanics (QM) we obtain that the individual superposition principle is scientifically unfounded and, as a consequence, the solution to the basic quantum observer`s problem.
We shall define the concept of a truth in the situation where different theories may have the same empirical…[Read more]

Aurelien Drezet replied to the topic Can Bohm's theory really solve the measurement problem? in the forum 2016 International Workshop on Quantum Observers 6 years ago
Dear Shan dear all, I gave a kind of reply to Shan’s work concerning psycho physical parallelism in the topic ‘The End of the ManyWorlds? (or Could we save Everett’s interpretation)’
with best regards Aurélien

Aurelien Drezet replied to the topic The End of the ManyWorlds? (or Could we save Everett’s interpretation) in the forum 2016 International Workshop on Quantum Observers 6 years ago
Dear Lev, don’t worry: my aim was only to recognize the influence that your view on MWI has on mine (your work on bohm with the ‘surrealistic’ bullet and the cat was very great as well). I will add a sentence that you dont share my view.
with best regards Aurélien 
Lev Vaidman replied to the topic The End of the ManyWorlds? (or Could we save Everett’s interpretation) in the forum 2016 International Workshop on Quantum Observers 6 years ago
I thank Aurelien for citing my works, but his acknowledgement to me at the end of his paper is misleading. Although I tried to explain my views to him in a couple of emails, I failed. Reading his presentation of my views I could not recognize them at all. I disagree with everything I saw in Aurelien paper.
Lev Vaidman 
Ken Wharton started the topic Measurements as External Constraints in the forum 2016 International Workshop on Quantum Observers 6 years ago
When two systems are in spatial contact, it’s natural for the bigger system to constrain the smaller system, not viceversa. For instance, consider classical statistical mechanics. When one system has an overwhelming number of possible internal states, it will act like a thermal reservoir for smaller systems in contact with it, constraining the…[Read more]

Peter J. Lewis replied to the topic Can Bohm's theory really solve the measurement problem? in the forum 2016 International Workshop on Quantum Observers 6 years ago
OK, good. But I guess I’m inclined to stick to my guns here — the relative positions of the particles determine the measurement outcome. Suppose the first particle is the one whose spin is being measured, and the second particle marks the top of the detection screen. Then if the two particles end up close together, the incoming particle is…[Read more]

Aurelien Drezet started the topic The End of the ManyWorlds? (or Could we save Everett’s interpretation) in the forum 2016 International Workshop on Quantum Observers 6 years ago
The aim of this discussion is to compare de Broglie’s (pilot wave interpretation :PWI) and Everett’s interpretation (Many Worlds interpretation: MWI) in order to see how both attempt to solve some of the key issues of quantum mechanics.
More specifically, I consider the problem of the ontology, the problem of the meaning of probability, and…[Read more] 
Peter J. Lewis replied to the topic Can Bohm's theory really solve the measurement problem? in the forum 2016 International Workshop on Quantum Observers 6 years ago
Thanks for the interesting post, Shan. Let me attempt to respond to your main argument. It is true that simply specifying the position of a Bohmian particle doesn’t pick out a measurement outcome. But neither does specifying the position of a classical particle. You need to specify the position of the particle relative to the apparatus — if it…[Read more]

editor started the topic The measurement problem revisited in the forum 2016 International Workshop on Quantum Observers 6 years ago
According to Maudlin’s (1995) formulation, the measurement problem originates from the incompatibility of the following three claims:
(C1). the wave function of a physical system is a complete description of the system;
(C2). the wave function always evolves in accord with a linear dynamical equation, e.g. the Schrodinger equation;
(C3). each…[Read more] 
editor started the topic What's wrong with the bare theory? in the forum 2016 International Workshop on Quantum Observers 6 years, 1 month ago
Note: The following text aims to elicit more discussions about the bare theory, which may help understand quantum observers more deeply.
Suppose that a quantum observer M is asked not with the question
Did you get a definite result to your xspin measurement?”, but with the question
Did you get some definite result to your xspin measurement,…[Read more]

editor started the topic How to solve the structured tails problem of dynamical collapse theories? in the forum 2016 International Workshop on Quantum Observers 6 years, 1 month ago
Note: The following text aims to elicit more discussions about the question of whether and how dynamical collapse theories can solve the structured tails problem when considering the status of quantum observers in the theory.
If a quantum observer being in a postmeasurement superposition indeed is consciously aware of a definite result, which is…[Read more]

editor started the topic Is Everett's approach consistent with psychophysical supervenience? in the forum 2016 International Workshop on Quantum Observers 6 years, 1 month ago
Note: The following text aims to elicit more discussions about the question of whether Everett’s approach can really solve the measurement problem when considering the status of quantum observers in the theory.
Let us analyze Everett’s approach to quantum mechanics. This approach claims that after the a quantum measurement of spin there will be…[Read more]

editor started the topic Can Bohm's theory really solve the measurement problem? in the forum 2016 International Workshop on Quantum Observers 6 years, 1 month ago
Note: The following text aims to elicit more discussions about the question of whether Bohm’s theory can really solve the measurement problem when considering the status of quantum observers in the theory.
Let us now consider Bohm’s approach or the hiddenvariables approach to quantum mechanics. As to Bohm’s approach, an analysis of the…[Read more]



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