The so-called 'quantum eraser' is an experiment that has prompted widespread confusion. In fact, it is nothing more than a photonic version of the EPR experiment. Nothing is erased, and there is no necessary retrocausation or 'temporal nonlocality,' beyond standard EPR correlations. I attempt to clear up the confusion in this paper, which has now … Continue reading The ‘Delayed Choice Quantum Eraser’ Neither Erases Nor Delays
Important New Book on Math Education
Bernice Kastner is a math educator whose innovative approach has helped to transform classrooms and enable many students to gain confidence and mastery in math. (She also happens to be my mother.) Her new book, The Role of Language in Teaching Children Math, is now out: https://www.austinmacauley.com/us/book/role-language-teaching-children-math From the publisher: "It can be difficult to … Continue reading Important New Book on Math Education
A critical look at popular ‘retrocausation’ claims. Do they hold up?
In this publication, I address popular uses of the term 'retrocausation' in connection with quantum theory, and find that there is much that needs to be corrected and clarified. Much of the discussion in the literature on this topic involves inconsistencies and equivocation about what retrocausation really is, and about what it can do. In … Continue reading A critical look at popular ‘retrocausation’ claims. Do they hold up?
Interview with Adam Alonzi on RTI, Schrodinger’s Cat, Time’s Arrow, Free Will
https://alonzipodcast.com/wp/2018/11/01/our-unseen-reality-the-relativistic-transactional-interpretation-of-quantum-mechanics-with-ruth-kastner/ Note correction: I should have said that a real photon goes FROM the emitter TO the absorber (said it backwards, LOL).
Visit to Buenos Aires, Grupo de Filosofía de las Ciencias.
I had fun in Buenos Aires last summer with the great people in the Grupo de Filosofía de las Ciencias. Here is my talk on how to understand the emergence of classicality from the quantum level in the context of statistical approaches. https://youtu.be/kvXYmB2qj88
Why “making sense of quantum theory” by denying that theories are about the world does not really work
This post is a critique of an interpretational approach to quantum theory known as "Qbism." Qbism is currently advocated primarily by Fuchs, Mermin, and Schack. Here, I discuss a little-known but powerful and important argument from Joe Henson regarding Qbism. Henson's argument discloses a crucial fallacy in Qbism's claim to "save locality" in quantum theory; … Continue reading Why “making sense of quantum theory” by denying that theories are about the world does not really work
John Gribbin’s blog post on TI
via A quantum myth for our times
What is the quantum/classical divide?
A talk given at the University of Buenos Aires in June 2017 on the difference between classical systems and quantum ones: https://www.youtube.com/watch?v=kvXYmB2qj88&feature=youtu.be (Note: Some of the slides were missing text here and there due to a compatibility issue; the correct version is provided here: Baires 2017 slides)
Is There Really “Retrocausation” in Time-Symmetric Approaches to Quantum Mechanics?
This is a preprint version of this paper: AIP Conference Proceedings 1841, 020002 (2017) R. E. Kastner Abstract. Time-symmetric interpretations of quantum theory are often presented as featuring "retrocausal" effects in addition to the usual forward notion of causation. This paper examines the ontological implications of certain time- symmetric theories, and finds that no dynamical notion … Continue reading Is There Really “Retrocausation” in Time-Symmetric Approaches to Quantum Mechanics?
Paper with John Cramer on Absorption in TI
I recently co-authored a paper with Transactional Interpretation (TI) originator John G. Cramer, which derives the Born Rule (quantum probability rule) for radiative processes (emission and absorption) in a simple and transparent way, based on the Wheeler-Feynman-Davies'absorber' theory of radiation. It also shows that absorption is indeed perfectly well-defined in TI (contrary to skeptical claims … Continue reading Paper with John Cramer on Absorption in TI