@ruth
active 1 month ago
Ruth Kastner replied to the topic Is there an inconsistent friend? in the forum Workshop on Wigner’s Friend 2018 1 month ago
Thanks Richard, let me address your comment that:
… if there were no true magnitude claims then an application of the Born rule would have nothing to which to assign probabilities!
The above statement/position depends on the notion of ‘magnitude claim’. That’s a linguistic entity, and I think we earlier agreed that QM doesn’t demand or depend…[Read more]

Ruth Kastner replied to the topic Is there an inconsistent friend? in the forum Workshop on Wigner’s Friend 2018 1 month, 1 week ago
Mark: of course, I’ve contended and continue to contend that the disease infecting conventional approaches to QM is that nobody can define ‘measurement’. This leaves adherents of these traditional approaches to simply help themselves to measurement results. In particular, I would have to respectfully differ with Richard’s comment:
The argument…

Ruth Kastner replied to the topic Is there an inconsistent friend? in the forum Workshop on Wigner’s Friend 2018 1 month, 1 week ago
Thanks very much Richard.
Of course, in the transactional picture, once photons are detected/actualized (as is necessary to yield a current), collapse has occurred, and conserved quantities (such as angular momentum, spin, etc) have been transferred. (Photons are the mediator of em processes such as the creation of electron current; for details,…[Read more] 
Ruth Kastner replied to the topic Is there an inconsistent friend? in the forum Workshop on Wigner’s Friend 2018 1 month, 2 weeks ago
Thanks very much, Richard.
Regarding the interpretation of probability, it seems that this is still an open question. I don’t think the Born probability is restricted to being about semantic objects such as claims. It can be directly about a system’s actualized properties (at least it certainly can in TI).
But in any case: I recognize that…[Read more] 
Ruth Kastner replied to the topic Is there an inconsistent friend? in the forum Workshop on Wigner’s Friend 2018 1 month, 2 weeks ago
Richard, do I understand correctly that in your proposed approach, measurement outcomes have no relation to values of observables for the system? My question arises from your statement:
In particular, it makes no assumption concerning the actual spin values of the measured particles, either before or after the spin measurements. It assumes only…

Ruth Kastner replied to the topic Is there an inconsistent friend? in the forum Workshop on Wigner’s Friend 2018 1 month, 2 weeks ago
Thanks, Richard for this clarification.
Of course, I think your analysis can also perfectly well apply to an ontic role for the quantum state.
Under an epistemic view of the quantum state, then it seems to me that if one posits that measurements really do have definite outcomes, then an implicit hidden variable view must be lurking in the…[Read more] 
Ruth Kastner replied to the topic Is there an inconsistent friend? in the forum Workshop on Wigner’s Friend 2018 1 month, 2 weeks ago
This is an interesting situation: assessments of the bearing and validity of the FR proof greatly depend on what quantum theory itself is taken to be. For example, Editor has referred to two different forms of QT:
(1) QT with collapse postulate — call it “QTCP”
(2) QT without collapse postulate — call it “QTNCP”
…and has noted, based on…[Read more] 
Ruth Kastner replied to the topic Is there an inconsistent friend? in the forum Workshop on Wigner’s Friend 2018 1 month, 2 weeks ago
I would just comment here that Brukner’s formulation of the measurement problem presupposes an epistemic interpretation of the quantum state relative to a particular observer. So his analysis and conclusions do not apply to cases in which the quantum state ontologically refers. In particular, he concludes that facts are necessarily…[Read more]

Ruth Kastner started the topic How we avoid getting to the Wigner's Friend situation in the first place in the forum Workshop on Wigner’s Friend 2018 1 month, 2 weeks ago
The Wigner’s Friend scenario was created to amplify the measurement problem as illustrated by Schrodinger’s Cat. We don’t encounter a Wigner’s Friend dilemma in the first place if we have a means of delineating, in physical terms, what constitutes ‘measurement’ (where that is described by von Neumann’s Process 1 nonunitary transition)…[Read more]

Ruth Kastner replied to the topic Is there an inconsistent friend? in the forum Workshop on Wigner’s Friend 2018 1 month, 2 weeks ago
Dear Editor: Should I start a new topic to address the measurement problem, which is what is being illustrated by the Wigner’s Friends scenario? In particular, we don’t encounter a Wigner’s Friend dilemma in the first place if we have a means of delineating, in physical terms, what constitutes ‘measurement’ (where that is described by von…[Read more]

Ruth Kastner posted a new activity comment 1 month, 3 weeks ago
I would just note that RTI is not subject to the recent ‘nogo’ proofs since it does not assert that quantum states are universally applicable; rather it has a natural limiting criterion for the applicability of quantum states. It particular, neither the Geiger counter nor the cat nor Wigner nor his friend (understood as spacetimelocatable obj…[Read more]

Ruth Kastner posted an update in the group Workshop on Wigner’s Friend 2018 1 month, 3 weeks ago
May I add as a relevant reference:
Kastner, R. E. On the Status of the Measurement Problem: Recalling the Relativistic Transactional Interpretation
International Journal of Quantum Foundations, 2017,
Volume 4, Issue 1, pages 128141 
Ruth Kastner joined the group Workshop on Wigner’s Friend 2018 1 month, 3 weeks ago

Ruth Kastner started the topic TI: Derivation of the Born Rule for Radiative Processes in the forum Retrocausal theories 7 months ago
The Transactional Interpretation involves advanced field states and is therefore considered a form of a ‘retrocausal’ interpretation, although in the relativistic development of TI (RTI), the advanced states (as well as the triggering retarded states) are complex objects and are subempirical (i.e., not spacetime processes). It is only the…[Read more]

Ruth Kastner started the topic The Transactional Interpretation is a Collapse Theory in the forum Collapse theories 7 months ago
It is not widely recognized that the Transactional Interpretation (TI) is a collapse theory; however, it is one that does not make ad hoc changes to the Schrodinger equation. Collapse is accounted for in TI by taking into account absorber response as a physical process (in the socalled ‘absorber theory’ of fields). Absorber response provides the…[Read more]

Ruth Kastner commented on the post, 2018 International Workshop on Quantum Foundations 7 months, 1 week ago
For the 2018 Workshop, I would like to discuss the Relativistic Transactional Interpretation, specifically the explicit derivation of the Born Rule for radiative processes as presented in my recent paper with John Cramer (https://arxiv.org/abs/1711.04501).
It appears clear that TI and RTI provide a physical account of measurement as well as a…[Read more]

Ruth Kastner wrote a new post, Topic for 2018 Int’l Workshop on Quantum Foundations 7 months, 1 week ago
I would like to discuss the Relativistic Transactional Interpretation, specifically the explicit derivation of the Born Rule for radiative processes as presented in my recent paper with John Cramer (https://arxiv.org/abs/1711.04501).
It appears clear that TI and RTI provide a physical account of measurement as well as a physical derivation of the Born Rule. Previous objections to TI (such as that of Maudlin) have been unambiguously resolved and/or nullified (e.g., https://arxiv.org/abs/1610.04609). Thus, TI is still perfectly viable and provides longsought solutions to pressing problems in quantum theory regarding the need for a physically grounded definition of ‘measurement’ and the source of the Born Rule (as well as a solution to the consistency problems for QFT as reflected in Haag’s theorem, http://www.ijqf.org/archives/2004). Curiously, however, TI is still not generally recognized as among the ‘mainstream’ approaches. I look forward to discussing with other IJQF members why that might be. Is it the apparent “action at a distance” of the directaction theory that is offputting? Is it because both Wheeler and Feynman abandoned their theory (though Wheeler was later advocating it again in 2003)? Comments welcome.

Ruth Kastner commented on the post, Taking Heisenberg’s Potentia Seriously 9 months ago
Thanks Dr. Sarfatti for your comments. The authors in no way assert that this matter is settled, but simply propose what we believe is a fruitful avenue for exploration.

Ruth Kastner commented on the post, Violation of the Born Rule: Implications for Macroscopic Fields. 9 months ago
Referees agreed with arguments in this paper and it has been accepted. Indeed there is no inconsistency; if there is no Born Rule violation in the limit Dr. Sarfatti discusses, then there is also no ‘real world’ applicability of such Born Rule violations as he has previously argued. The paper simply shows that real world Born Rule violations lead…[Read more]

Ruth Kastner wrote a new post, Submission: Quantifying Absorption in the Transactional Interpretation 10 months, 1 week ago
R. E. Kastner, John G. Cramer 3 Feb. 2018
Abstract: The Transactional Interpretation offers a solution to the measurement problem by identifying specific physical conditions precipitating the nonunitary […]
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I would just note that RTI is not subject to the recent ‘nogo’ proofs since it does not assert that quantum states are universally applicable; rather it has a natural limiting criterion for the applicability of quantum states. It particular, neither the Geiger counter nor the cat nor Wigner nor his friend (understood as spacetimelocatable obj…[Read more]