The Afshar experiment (2005 ) is a lovely variant on the famous two-slit experiment. In this experiment, a grid is placed at the location of the dark fringes in what would be an interference pattern, but downstream from that location, the photon beam is subjected to a "which slit" measurement by way of lenses. However, … Continue reading Demystifying the Afshar Experiment →

A review from UK reader "Jehannum" was recently posted on the amazon.com page for my recent book Adventures in Quantumland: Exploring Our Unseen Reality (WSP, 2019). I reproduce it below: ***************** 5.0 out of 5 stars This book provides a revolutionary understanding of quantum physics. It's common to come out of a study of quantum … Continue reading Review of Adventures in Quantumland by “Jehannum” (amazon.com) →

(This is a preprint version of a technical paper. I'm making it available here in addition to the usual preprint servers. Questions/comments welcome.) Click here for the paper:  Light Tight Box Preprint Abstract: This paper discusses the nature of the boundary condition applying to the direct-action theory of fields, also known as the 'absorber' theory, … Continue reading Why the Quantum Absorber Condition is Not a Light-Tight Box →

It's always a pleasure to talk with Jeffrey Mishlove. In this interview we talked about the Transactional Interpretation and related ideas: https://youtu.be/E6NNWdVCQZU

I gave a talk on the Transactional Interpretation and how it solves quantum paradoxes at the "Copenhagen and Beyond" Conference at Chapman University, CA (Oct. 18, 2019). The title was "Quantum Paradoxes: To Resolve or To Acquiesce?" It can be found here: https://digitalcommons.chapman.edu/cib-2019/cib/schedule/10/

A recent paper by Frauchiger and Renner has brought to light a serious problem with  conventional approaches to quantum theory, by deriving a contradiction using those approaches. In  FR Paradox Kastner 10.17.19  I argue that the paradox shows that quantum theory leads to absurdities and inconsistencies unless there is a clear physical criterion for 'measurement'.  … Continue reading Latest incarnation of the Schrödinger Cat Paradox forces a new view of quantum theory →

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 →

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 →

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? →