Jim talks with Bruna Shinohara of CMC Microsystems. Quantum computing and machine learning are both currently making huge strides.  So it is not strange that people are trying to use quantum computing for machine learning.

Jim talks with Alex Jurgens about Maxwellian ratchets, automata that are similar to Maxwell's Demon.  They talk about their implications for information processing and entropy.

http://frontiers.physicsfm.com/77

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 talks with Claus Kiefer about the implications of Goedel's incompleteness theorems on the search for the theory.

Show Notes: http://frontiers.physicsfm.com/76

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.

Jim and Randy talk about gravitational waves.

Jim and Randy discuss a possible "fifth force," the hypothetical X17 particle that has been seen in several experiments.

Erratum: The g-2 of the muon was shown to be off by 1 part in 500,000 in 2001 at Brookhaven. It may not be in there, I'm not sure how much of that I cut out.

Show Notes: http://frontiers.physicsfm.com/50

Jim and Randy discuss the apparent creation of quanta seen by comparing the viewpoints of relatively accelerating observers -- the Unruh Effect.

(There is a little noise that shows up on Randy's track half way through - I did my best)

Show Notes: http://frontiers.physicsfm.com/49
(links to papers, podcasts, and more!)

Jim talks with Nick Ormrod and V. Vilasini about their use of categorical probability theory to analyze the measurement problem.  We discuss categorical probability theory, which allows them to abstract from particular mathematical formulations of quantum mechanics to more general ideas about states and measurements and observers than found in Hilbert space formulations.  They use this to look at the various properties of quantum mechanics and how they relate to each other, in particular how relativity affects the measurement problem.

Show Notes: http://frontiers.physicsfm.com/75

Randy introduces Jim to the Gertsenshtein effect, the conversion of gravitational waves to electromagnetic waves through resonances.

Show Notes: http://frontiers.physicsfm.com/48

Randy introduces Jim to Sabine Hossenfelder's bimetric theory of gravity. In this gravitational theory, there are two types of matter whose only interaction is through gravitation. However, each one reacts to space-time differently, resulting in different metric tensors for each. In low-curvature situations, this creates a kind of anti-gravitation.

Show Notes: http://frontiers.physicsfm.com/47

Randy and Jim discuss experiments that purport to show that there is no such thing as objective reality.

Show Notes: http://frontiers.physicsfm.com/46

Jim and Randy discuss loop quantum gravity, and integration of quantum mechanics and gravity that quantizes space-time itself through the use of uncertain quanta of volumes and the random connections between them.

Jim and Randy discuss experiments that put a minimum superluminal speed of communication between parts of a wavefunction.

Show Notes: http://frontiers.physicsfm.com/44

Randy introduces Jim to a refutation of the positive energy theorem in a universe with a cosmological constant.

Show Notes: http://frontiers.physicsfm.com/43

Jim and Randy discuss Eric Verlinde's theory thermodynamic theory of gravity. This theory purports to explain gravitational attraction and inertia through statistical mechanics.

Show Notes: http://frontiers.physicsfm.com/42

Randy and Jim discuss the chameleon field -- a way to model dark energy with a scalar boson of varying strength.

Show Notes: http://frontiers.physicsfm.com/41

Randy tells Jim about a way to use an extension of an extension of the complex numbers to reveal the nature of elementary particles.

Show Notes: http://frontiers.physicsfm.com/40

Randy tells Jim about experiments with Neutrons and Photons in materials that exhibit negative effective mass. Not only do these effects show that the inertial mass of quasiparticles in a material can become negative, they show that these negative mass quasiparticles act like they have negative gravitational mass, as well.

Show Notes: http://frontiers.physicsfm.com/39

Jim talks with David Wolpert about the non-equilibrium behavior of computation, what it means for entropy, and how it relates to traditional thermodynamics.

Show Notes: http://frontiers.physicsfm.com/74

Jim discusses why the world we observe is 4-dimensional with Randy. We discuss anthropic and fundamental reasons why we need 3 dimensions and no more than one time dimension for reasons of complexity, predictability and stability.

Show Notes: http://frontiers.physicsfm.com/38

Randy explains to Jim theories on how to incorporate a native angular momentum into general relativity.

Show Notes: http://frontiers.physicsfm.com/37

Randy tells Jim about recent results in the description of the electromagnetic stress tensor in metamaterials. In particular, we discuss the efforts to computationally model the stress tensor in amorphous metamaterials.

Show Notes: http://frontiers.physicsfm.com/36

Jim and Randy explore the landscape of string theory in the anthropic manner put forward by Leonard Susskind.

Show Notes:
http:frontiers.physicsfm.com/35

CPT Symmetry is a fundamental symmetry in the standard model. Jim and Randy discuss what happens when it is applied to general relativity.

Show Notes: frontiers.physicsfm.com/34

[Really sorry for the muted tracks on the first upload. The problem has been fixed. - J]

Jim and Randy look at how quantum mechanics is affected by time. Most importantly, what happens when temporal boundary conditions are used to create standing waves in the wave function of a particle?

Show Notes: http://frontiers.physicsfm.com/33

Jim talks to Randy about the amount of time it takes for an electron to tunnel through a forbidden region of space. Astoundingly, how quickly this happens has been a subject of debate for eighty years and is still unresolved.

Show Notes: http://frontiers.physicsfm.com/32

Jim discusses the Parameterized Post-Newtonian formalism with Randy. The PPN framework is a general, linearized metric theory of gravity that can simulate all metric theories of gravity and compare them to solar system sized experiments.

Show Notes: http://frontiers.physicsfm.com/31

Jim and Randy discuss the consistent histories interpretation of quantum mechanics. The brainchild of Robert Griffiths and with a surprisingly strong set of supporters, Consistent Histories seems to be a strong, logical description of what happens in the quantum world.

Show Notes: http://frontiers.physicsfm.com/30

Jim and Randy discuss how modifications to general relativity can be used to mimic the effects of dark energy. They discuss various forms of gravitational theory that can do the job, as well as the field particles that mediate their "fifth force."

Show Notes: http://frontiers.physicsfm.com/29

Jim discusses quantum money with Jiahui Liu.  Quantum money is a linchpin of quantum cryptography.  The ability to create secure banknotes using quantum computers would allow even more secure methods of encryption for communications. 

Jim and Randy review two very convincing papers that make the claim that the Casimir effect is due to materials fluctuations and not the zero point energy.

Show Notes: http://frontiers.physicsfm.com/28

Jim talks to Randy about the different ways in which the equivalence principle of general relativity can be formulated. More than just the equivalence of accelerations, the different possible meanings of the equivalence principle mean different things about how gravity works. From weak to strong, from Einstein's equivalence principle to Schiff's conjecture, the implications of these theories are explored.

Show Notes: http://frontiers.physicsfm.com/27

Randy shows Jim an idea for generating antimatter using the Casimir effect that doesn't require a collider.

Show Notes: http://frontiers.physicsfm.com/26

Randy introduces Jim to several ways in which people have theorized that gravity can be used to propel an object through space. The slingshot effect is the only proven method here, but people have found many ways that theoretically could induce propulsion taking advantage of non-commutative motions in space-time, negative inertia, artificially-induced gravitational dipoles, and creating bubbles in space-time.

Show Notes: http://frontiers.physicsfm.com/25