Physics Frontiers
82 episodes - English - Latest episode: 26 days ago - ★★★★ - 101 ratingsJim Rantschler and Randy Morrison discuss physics from elementary particles to cosmological effects at the limits of our theoretical knowledge or have recently emerged.
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Episodes
Episode 77: Maxwellian Ratchets with Alex Jurgens
March 31, 2024 00:00 - 1 hour - 57.7 MBJim 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
Episode 76: Undeciability and Theories of Everything with Claus Kiefer
January 29, 2024 00:00 - 49 minutes - 44.4 MBJim 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
Episode 75: Categorical Probability and the Measurement Problem
August 20, 2023 00:00 - 1 hour - 46.3 MBJim 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 parti...
Episode 74: Stochastic Thermodynamics with David Wolpert
July 09, 2023 00:00 - 50 minutes - 32.8 MBJim 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
Episode 73: Quantum Money with Jiahui Liu
June 18, 2023 00:00 - 1 hour - 43.9 MBJim 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.
Episode 72: The Failure of the Born Rule Under Gravity with Antony Valentini
April 23, 2023 00:00 - 1 hour - 51.7 MBJim talks with Antony Valentini about the difficulties of interpretation of quantum mechanics in light of quantum gravity. In particular, Antony discusses the failure of the Born Rule due to the impossibility of normalization (the fact that probabilities must sum to 100%) at that scale, and therefore the need to interpret the wavefunction as something more than merely the knowledge of the observer about the system. They spend some time talking about the de Broglie-Bohm interpretat...
Episode 72: Born Rule and Gravity with Antony Valentini
April 23, 2023 00:00 - 1 hour - 51.7 MBJim talks with Antony Valentini about the difficulties of interpretation of quantum mechanics in light of quantum gravity. In particular, Antony discusses the failure of the Born Rule due to the impossibility of normalization (the fact that probabilities must sum to 100%) at that scale, and therefore the need to interpret the wavefunction as something more than merely the knowledge of the observer about the system. They spend some time talking about the de Broglie-Bohm interpretat...
Episode 71: Primordial Graviton Background
February 19, 2023 00:00 - 45 minutes - 34.5 MBJim talks with Sunny Vagnozzi about using the Primoridial Graviton Background to rule out all inflation models. Show Notes: http://frontiers.physicsfm.com/71
Episode 70: Path Integrals and Entanglement with Ken Wharton
December 18, 2022 00:00 - 46 minutes - 36.2 MBJim 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
Episode 69: The Flavor Puzzle with Joe Davighi
November 20, 2022 00:00 - 43 minutes - 35.4 MBJim 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.
Episode 69: The Flavor Puzzle
November 20, 2022 00:00 - 42 minutes - 35.4 MBJim 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.
Episode 68: Quantum Resource Theories with Gilad Gour
September 26, 2022 00:00 - 51 minutes - 35.4 MBJim 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 ...
Episode 67: Optical Gravity with Matthew R. Edwards
August 14, 2022 00:00 - 35 minutes - 29.1 MBJim 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
Episode 67: Optical Gravity
August 14, 2022 00:00 - 34 minutes - 29.1 MBJim 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
Episode 66: The Limit of General Relativity with James Owen Weatherall
June 26, 2022 00:00 - 30 minutes - 26.9 MBJim 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...
Episode 65: Causality, Time and the Experiment Paradox with Michal Eckstein
May 22, 2022 00:00 - 1 hour - 44.7 MBJim 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
Episode 64: Born's Rule with Blake Stacey
April 24, 2022 00:00 - 29 minutes - 20.1 MBJim 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
Episode 63: Gleason's Theorem with Blake Stacey
March 20, 2022 00:00 - 44 minutes - 30.3 MBJim 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
Episode 62: Deformed Special Relativity
February 13, 2022 00:00 - 39 minutes - 26.8 MBJim 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
Episode 61: Dark Stars
October 31, 2021 00:00 - 42 minutes - 29.3 MBJim and Randy talk about alternatives to black holes without event horizons or singularities. Show Notes: http://frontiers.physicsfm.com/61
Episode 60: Warp Bubbles
September 12, 2021 00:00 - 43 minutes - 29.6 MBRandy tells Jim about developments of metrics describing isolated spacetime bubbles that could, possibly, move faster than light. Show Notes: http://frontiers.physicsfm.com/60
Episode 59: The Hubble Crisis
July 05, 2021 00:00 - 48 minutes - 33.5 MBRandy 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
Episode 58: Phantom Matter
June 06, 2021 00:00 - 38 minutes - 26.1 MBJim 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
Episode 57: Quantum Effects in Gravitational Waves
May 02, 2021 00:00 - 26 minutes - 18.1 MBRandy 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
Episode 56: Anomalous Magnetic Moment of the Muon
April 01, 2021 20:29 - 44 minutes - 17.4 MBJim 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
Episode 55: Anomalous Magnetic Moment of the Muon
April 01, 2021 00:00 - 44 minutes - 30.6 MBJim 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
Episode 54: Multiversality
December 07, 2020 00:00 - 37 minutes - 25.8 MBJim and Randy discuss the rationales for multiverses based on quantum mechanics, string theory, and the anthropic principle. Show Notes: http://frontiers.physicsfm.com/55
Episode 55: Multiversality
December 07, 2020 00:00 - 37 minutes - 25.8 MBJim and Randy discuss the rationales for multiverses based on quantum mechanics, string theory, and the anthropic principle. Show Notes: http://frontiers.physicsfm.com/55
Episode 54: The ANITA Experiment
October 18, 2020 00:00 - 45 minutes - 31.1 MBRandy 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
The ANITA Experiment
October 18, 2020 00:00 - 45 minutes - 31.1 MBRandy 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
Electromagnetic Gravitational Repulsion
August 17, 2020 00:00 - 41 minutes - 28.3 MBRandy tells Jim about ways in which electromagnetism reduces the gravitational attraction caused by a body.
Sterile Neutrinos
July 08, 2020 00:00 - 37 minutes - 25.9 MBJim and Randy discuss the hypothesis of sterile neutrinos, neutrinos that are even more ghostly than neutrinos that are dark matter candidates.
Gravitational Wave Astronomy
June 10, 2020 00:00 - 38 minutes - 26.4 MBJim and Randy talk about gravitational waves.
X17
May 03, 2020 00:00 - 38 minutes - 26.4 MBJim 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
The Unruh Effect
April 04, 2020 00:00 - 39 minutes - 27.2 MBJim 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!)
The Gertsenshtein Effect
January 19, 2020 00:00 - 40 minutes - 27.6 MBRandy introduces Jim to the Gertsenshtein effect, the conversion of gravitational waves to electromagnetic waves through resonances. Show Notes: http://frontiers.physicsfm.com/48
Bimetric Gravity
November 24, 2019 00:00 - 46 minutes - 32.2 MBRandy 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
Wigner's Friend
September 22, 2019 00:00 - 44 minutes - 30.7 MBRandy and Jim discuss experiments that purport to show that there is no such thing as objective reality. Show Notes: http://frontiers.physicsfm.com/46
Loop Quantum Gravity
August 16, 2019 00:00 - 44 minutes - 30.5 MBJim 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.
Spooky Action at a Distance
July 16, 2019 00:00 - 47 minutes - 32.9 MBJim and Randy discuss experiments that put a minimum superluminal speed of communication between parts of a wavefunction. Show Notes: http://frontiers.physicsfm.com/44
The Positive Energy Theorem
June 06, 2019 00:00 - 34 minutes - 23.6 MBRandy introduces Jim to a refutation of the positive energy theorem in a universe with a cosmological constant. Show Notes: http://frontiers.physicsfm.com/43
Entropic Gravity
May 04, 2019 00:00 - 36 minutes - 25 MBJim 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
The Chameleon Field
February 24, 2019 00:00 - 33 minutes - 22.9 MBRandy 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
The Octonions
December 23, 2018 00:00 - 52 minutes - 36.1 MBRandy 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
Negative Effective Mass
December 09, 2018 00:00 - 35 minutes - 24.5 MBRandy 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
The Dimensionality of Space-Time
November 25, 2018 00:00 - 43 minutes - 30 MBJim 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
The Einstein-Cartan Torsion Field Theory
October 30, 2018 00:00 - 35 minutes - 24.3 MBRandy explains to Jim theories on how to incorporate a native angular momentum into general relativity. Show Notes: http://frontiers.physicsfm.com/37
The Metamaterial Stress Tensor
October 15, 2018 00:00 - 42 minutes - 29.2 MBRandy 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
The String Theory Landscape
September 22, 2018 00:00 - 42 minutes - 29.2 MBJim 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 and Gravitation
August 10, 2018 21:56 - 32 minutes - 22.1 MBCPT 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]