Ruth E. Kastner earned her M.S. in Physics and Ph.D. in Philosophy (History and Philosophy of Science) and the University of Maryland, College Park (1999). She has taught a variety of philosophy and physics courses throughout the Baltimore-Washington corridor, and currently is a member of the Foundations of Physics group at UMCP. She is also an Affiliate of the physics department at the SUNY Albany campus. She specializes in time-symmetry and the Transactional Interpretation (TI) of quantum mechanics, and in particular has extended the original TI of John Cramer to the relativistic domain. Her interests and publications include topics in thermodynamics and statistical mechanics, quantum ontology, counterfactuals, spacetime emergence, and free will. She is the author of two books: The Transactional Interpretation of Quantum Mechanics: The Reality of Possibility (Cambridge, 2012) and Understanding Our Unseen Reality: Solving Quantum Riddles (Imperial College Press, 2015). She is also an Editor of the collected volume Quantum Structural Studies (World Scientific, 2016).

John G. Cramer is Professor Emeritus in Physics at the University of Washington (UW) in Seattle, where he has had five decades of experience in teaching undergraduate and graduate level physics. John was born in Houston, Texas on October 24, 1934, and was educated in the Houston Public Schools (Poe, Lanier, Lamar) and at Rice University, where he received a BA (1957), MA (1959), and Ph.D. (1961) in Experimental Nuclear Physics. He began his professional physics career as a Postdoc and then Assistant Professor at Indiana University, Bloomington, Indiana (1961–1964) before joining the Physics Faculty of the University of Washington. He has done cutting-edge research in experimental and theoretical nuclear and ultra-relativistic heavy ion physics, including active participation in Experiments NA35 and NA49 at CERN, Geneva, Switzerland, and the STAR Experiment at RHIC, Brookhaven National Laboratory, Long Island, NY. He has also worked in the foundations of quantum mechanics (QM) and is the originator of the transactional interpretation of quantum mechanics. He is co-author of around 300 publications in nuclear and ultra-relativistic heavy ion physics published in peer-reviewed physics journals, as well as over 141 publications in conference proceedings, and has written several chapters for multiauthor books about physics. His recent book on the transactional interpretation, The Quantum Handshake – Entanglement, Nonlocality and Transactions, was published by Springer in 2016.