Jim talks with Sunny Vagnozzi about using the Primoridial Graviton Background to rule out all inflation models. Show Notes: http://frontiers.physicsfm.com/71

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

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.

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

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

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

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

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

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

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

Jim and Randy talk about alternatives to black holes without event horizons or singularities.Show Notes: http://frontiers.physicsfm.com/61

Randy tells Jim about developments of metrics describing isolated spacetime bubbles that could, possibly, move faster than light.Show Notes: http://frontiers.physicsfm.com/60

Randy and Jim discuss the current tension between measurements of the Hubble constant by different methods, and some attempts to resolve the issue.Show Notes: http://frontiers.physicsfm.com/59

Jim and Randy talk about the Higgs portal to dark matter and the nightmare scenario for particle physicists: what if the LHC never saw any traces of supersymmetric particles?Show Notes: http://frontiers.physicsfm.com/58

Randy and Jim talk about two proposals to use gravitational wave interferometry to show that gravitons exist through noise measurements.Show Notes: http://frontiers.physicsfm.com/57

Jim and Randy discuss the measurements of the anomalous magnetic moment of the muon and some of the ways in which the discrepancy between theory and experiment could manifest themselves in new physics.Show Notes: http://frontiers.physicsfm.com/56

Jim and Randy discuss the rationales for multiverses based on quantum mechanics, string theory, and the anthropic principle.Show Notes: http://frontiers.physicsfm.com/55

Randy and Jim talk about the strange results of the ANITA experiment: tau neutrinos that seem to come up out of the Earth.Notes: http://frontiers.physicsfm.com/54

Randy tells Jim about ways in which electromagnetism reduces the gravitational attraction caused by a body.

Jim and Randy discuss the hypothesis of sterile neutrinos, neutrinos that are even more ghostly than neutrinos that are dark matter candidates.