
Physics Frontiers
Jim Rantschler and Randy Morrison discuss physics from elementary particles to cosmological effects at the limits of our theoretical knowledge or have recently emerged.
Latest episodes

Feb 19, 2023 • 46min
Episode 71: Primordial Graviton Background
Jim talks with Sunny Vagnozzi about using the Primoridial Graviton Background to rule out all inflation models. Show Notes: http://frontiers.physicsfm.com/71

Dec 18, 2022 • 47min
Episode 70: Path Integrals and Entanglement with Ken Wharton
Jim talks with Ken Wharton about how to describe entangled states as sums over histories of particle paths using the path integral method. He shows how this works for Bell-type experiments, entanglements swapping, delayed choice experiments, and the triangle network. This leads to a second way to describe what happens quantum mechanically without introducing non-locality (but requiring other classical ideas to break down).Show Notes: http://frontiers.physicsfm.com/70

Nov 20, 2022 • 43min
Episode 69: The Flavor Puzzle with Joe Davighi
Jim talks with Joe Davighi of the University of Zurich about the flavor unification at high energies - the merging of all leptons into one kind of particle. The discussion includes symmetries in particle physics, symmetry breaking at low temperatures, and unification schemes in general. Joe also discusses both leptoquarks and proton stability in the context of his theory.

Sep 26, 2022 • 51min
Episode 68: Quantum Resource Theories with Gilad Gour
Jim talks with Gilad Gour of the University of Toronto about quantum resource theories. These are theories of largish systems that describe the relationships between possible states by the different levels of resources required for each. By using resources, a system can move from one state to another. This results in a partial order where between two states there could be two different states inaccessible to one another. Although (usually) these coalesce into an order based on a single property of thermodynamically-sized systems, the entropy, a few do not.Show Notes: http://frontiers.physicsfm.com/68

Aug 14, 2022 • 35min
Episode 67: Optical Gravity with Matthew R. Edwards
Jim talks with Matthew R. Edwards about his theory of Optical Gravity. This is a Le Sage model of gravity based on graviton filiments.Show Notes: http://frontiers.physicsfm.com/67

Jun 26, 2022 • 30min
Episode 66: The Limit of General Relativity with James Owen Weatherall
Jim talks with James Owen Weatherall about his work on viewing general relativity as an effective field theory and where it should give way to another theory. General relativity does a very good job of describing the world we see in astronomical observations, but certain results, e.g. singularities, and certain limits, e.g. the Planck scale, hint that there should be another theory that supersedes it. Jim Weatherall argues that this is in a high curvature regime.Show Notes: http://frontiers.physicsfm.com/66

May 22, 2022 • 1h 5min
Episode 65: Causality, Time and the Experiment Paradox with Michal Eckstein
Jim talks with Michal Eckstein of the Copernicus Institute for Interdisciplinary Studies about how two different kinds of ordering, chronological and causal, give rise to a robust idea of time. Additionally, we discuss the Experiment Paradox, a generalization of other measurement-type paradoxes in physics.Show Notes: http://frontiers.physicsfm.com/65

Apr 24, 2022 • 29min
Episode 64: Born's Rule with Blake Stacey
Jim talks with Blake Stacey about recent attempts to replace Born's rule. Born's rule is the principle used in quantum mechanics that associates quantum states to the probability of measurement. There has been a recent interest in Quantum Foundations to try to find a less arbitrary rationale for this procedure. Show Notes: http://frontiers.physicsfm.com/64

Mar 20, 2022 • 44min
Episode 63: Gleason's Theorem with Blake Stacey
Jim talks with Blake Stacey about Gleason's Theorem, a foundational topic in the foundations of quantum mechanics. Gleason's theorem gives us a set of characteristic states for a measurement and the probability rule associated measuring them. This is the first part of the interview. The second part will discuss recent attempts to replace the Born Rule.Show Notes: http://frontiers.physicsfm.com/63

Feb 13, 2022 • 39min
Episode 62: Deformed Special Relativity
Jim and Randy talk about how special relativity might be amended to incorporate a minimum length scale. Such scales are common in quantum gravity theories, and in the limit where both QM and GR are less important, QG should induce first order corrections to SR. We then talk about how these corrections seem to lead to unreasonable paradoxes.Show Notes: http://frontiers.physicsfm.com/62