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Podcast Profile: Physics Frontiers

podcast imageTwitter: @_PhysicsFM_@PhysicsMystic
74 episodes
2016 to present
Average episode: 44 minutes
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Categories: Physics • Two Hosts

Podcaster's summary: Jim 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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List Updated: 2023-Dec-02 13:28 UTC. Episodes: 74. Feedback: @TrueSciPhi.

2023-Aug-20 • 67 minutes
Episode 75: Categorical Probability and the Measurement Problem
Jim talks with Nick Ormrod and V. Vilasini about their use of categorical probability theory to a...
2023-Jul-09 • 50 minutes
Episode 74: Stochastic Thermodynamics with David Wolpert
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:
2023-Jun-18 • 61 minutes
Episode 73: Quantum Money with Jiahui Liu
Jim discusses quantum money with Jiahui Liu.  Quantum money is a linchpin of quantum cryptog...
2023-Apr-23 • 74 minutes
Episode 72: Born Rule and Gravity with Antony Valentini
Jim talks with Antony Valentini about the difficulties of interpretation of quantum mechanics in ...
2023-Feb-19 • 46 minutes
Episode 71: Primordial Graviton Background
Jim talks with Sunny Vagnozzi about using the Primoridial Graviton Background to rule out all inf...
2022-Dec-18 • 47 minutes
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 parti...
2022-Nov-20 • 43 minutes
Episode 69: The Flavor Puzzle with Joe Davighi
Jim talks with Joe Davighi of the University of Zurich about the flavor unification at high energ...
2022-Sep-26 • 51 minutes
Episode 68: Quantum Resource Theories with Gilad Gour
Jim talks with Gilad Gour of the University of Toronto about quantum resource theories.  The...
2022-Aug-14 • 35 minutes
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 mo...
2022-Jun-26 • 30 minutes
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...
2022-May-22 • 65 minutes
Episode 65: Causality, Time and the Experiment Paradox with Michal Eckstein
Jim talks with Michal Eckstein of the Copernicus Institute for Interdisciplinary Studies about ho...
2022-Apr-24 • 29 minutes
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 th...
2022-Mar-20 • 44 minutes
Episode 63: Gleason's Theorem with Blake Stacey
Jim talks with Blake Stacey about Gleason's Theorem, a foundational topic in the foundations of q...
2022-Feb-13 • 39 minutes
Episode 62: Deformed Special Relativity
Jim and Randy talk about how special relativity might be amended to incorporate a minimum length ...
2021-Oct-31 • 43 minutes
Episode 61: Dark Stars
Jim and Randy talk about alternatives to black holes without event horizons or singularities.Show Notes:
2021-Sep-12 • 43 minutes
Episode 60: Warp Bubbles
Randy tells Jim about developments of metrics describing isolated spacetime bubbles that could, possibly, move faster than light.Show Notes:
2021-Jul-05 • 49 minutes
Episode 59: The Hubble Crisis
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:
2021-Jun-06 • 38 minutes
Episode 58: Phantom Matter
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:
2021-May-02 • 26 minutes
Episode 57: Quantum Effects in Gravitational Waves
Randy and Jim talk about two proposals to use gravitational wave interferometry to show that gravitons exist through noise measurements. Show Notes:
2021-Apr-01 • 45 minutes
Episode 56: Anomalous Magnetic Moment of the Muon
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:
2020-Dec-07 • 38 minutes
Episode 55: Multiversality
Jim and Randy discuss the rationales for multiverses based on quantum mechanics, string theory, and the anthropic principle. Show Notes:
2020-Oct-18 • 45 minutes
Episode 54: The ANITA Experiment
Randy and Jim talk about the strange results of the ANITA experiment: tau neutrinos that seem to come up out of the Earth. Notes:
2020-Aug-17 • 41 minutes
Electromagnetic Gravitational Repulsion
Randy tells Jim about ways in which electromagnetism reduces the gravitational attraction caused by a body.
2020-Jul-08 • 38 minutes
Sterile Neutrinos
Jim and Randy discuss the hypothesis of sterile neutrinos, neutrinos that are even more ghostly than neutrinos that are dark matter candidates.
2020-Jun-10 • 38 minutes
Gravitational Wave Astronomy
Jim and Randy talk about gravitational waves.
2020-May-03 • 38 minutes
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:
2020-Apr-04 • 40 minutes
The Unruh Effect
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: (links to papers, podcasts, and more!)
2020-Jan-19 • 40 minutes
The Gertsenshtein Effect
Randy introduces Jim to the Gertsenshtein effect, the conversion of gravitational waves to electromagnetic waves through resonances. Show Notes:
2019-Nov-24 • 47 minutes
Bimetric Gravity
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:
2019-Sep-22 • 45 minutes
Wigner's Friend
Randy and Jim discuss experiments that purport to show that there is no such thing as objective reality. Show Notes:
2019-Aug-16 • 44 minutes
Loop Quantum Gravity
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.
2019-Jul-16 • 48 minutes
Spooky Action at a Distance
Jim and Randy discuss experiments that put a minimum superluminal speed of communication between parts of a wavefunction. Show Notes:
2019-Jun-06 • 34 minutes
The Positive Energy Theorem
Randy introduces Jim to a refutation of the positive energy theorem in a universe with a cosmological constant. Show Notes:
2019-May-04 • 36 minutes
Entropic Gravity
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:
2019-Feb-24 • 33 minutes
The Chameleon Field
Randy and Jim discuss the chameleon field -- a way to model dark energy with a scalar boson of varying strength. Show Notes:
2018-Dec-23 • 53 minutes
The Octonions
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:
2018-Dec-09 • 36 minutes
Negative Effective Mass
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:
2018-Nov-25 • 44 minutes
The Dimensionality of Space-Time
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:
2018-Oct-30 • 35 minutes
The Einstein-Cartan Torsion Field Theory
Randy explains to Jim theories on how to incorporate a native angular momentum into general relativity. Show Notes:
2018-Oct-15 • 42 minutes
The Metamaterial Stress Tensor
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:
2018-Sep-22 • 42 minutes
The String Theory Landscape
Jim and Randy explore the landscape of string theory in the anthropic manner put forward by Leonard Susskind. Show Notes:
2018-Aug-10 • 32 minutes
CPT Symmetry and Gravitation
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: [Really sorry for the muted tracks on the first upload. The problem has been fixed. - J]
2018-Jul-25 • 35 minutes
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:
2018-Jul-07 • 47 minutes
Tunneling Time
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:
2018-Jun-08 • 42 minutes
Post-Newtonian Gravitation
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:
2018-May-24 • 46 minutes
The Consistent Histories Interpretation of Quantum Mechanics
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:
2018-May-16 • 47 minutes
Gravitational Alternatives to Dark Energy
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:
2018-Apr-25 • 41 minutes
The Quantum Vacuum and the Casimir Effect
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:
2018-Apr-15 • 46 minutes
The Gravitational Equivalence Principles
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:
2018-Mar-25 • 40 minutes
Antimatter Production at a Potential Boundary
Randy shows Jim an idea for generating antimatter using the Casimir effect that doesn't require a collider. Show Notes:
2018-Mar-16 • 58 minutes
Gravitational Field Propulsion
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:
2018-Feb-24 • 25 minutes
The Island of Stability
Randy tells Jim about the island of stability: a theoretically predicted oasis of stable nuclear isotopes that researchers keep getting nearer and nearer to discovering. Randy and Jim talk about what they are, how researchers are trying to produce the isotopes, and the theoretical methods that predict their existence. Show Notes:
2018-Feb-09 • 73 minutes
Dark Energy
Randy helps Jim get a handle on Dark Energy. Why do we need it? What could it be? What does it have to do with you? How close are we to knowing anything about it? Show Notes:
2018-Jan-22 • 37 minutes
Weyl and Quasiparticles
Jim and Randy discuss quasiparticles recently found in condensed matter systems that mirror particles theorized nearly a hundred years ago, but never found in the vacuum. Weyl particles are massless fermions, and once it was hoped that neutrinos would turn out to be this kind of particle, and Majorana fermions have real-valued wave functions and therefore many strange and possibly useful properties. Show Notes:
2018-Jan-11 • 39 minutes
The Origin of Inertia
Randy tells Jim about a scheme that uses Mach's Principle - the idea that there is a preferred background frame with respect to the fixed stars - to explain the origin of inertia. Show Notes:
2017-Dec-22 • 62 minutes
Time Crystals
Jim talks to Randy about structures that are periodic in time like crystals are periodic in space. Show notes:
2017-Dec-06 • 45 minutes
The 2T Physics of Itzhak Bars
Randy tells Jim about a theory that complements other theories of fundamental physics based upon a phase space symmetry between the 4-position and the 4-momentum of a particle. The upshot of the theory is that there should be a second time dimension and a fourth space dimension, both macroscopic in extent, and the physics we see are 4D projections from the larger 6D space-time. Show notes:
2017-Nov-24 • 44 minutes
The Physics of Time Travel
Randy and Jim talk about traveling through through time, discussing relativity and, in particular, Kurt Goedel's solution for closed timelike curves in General Relativity. Show notes:
2017-Nov-06 • 38 minutes
Stochastic Resonance Energy Harvesting
Randy tells Jim about ways in which external vibrations can be used to do useful work in large-scale devices. These processes look at have happens when bistable systems (e.g., a bent cantilever) are subjected to random forcing from the environment. Show notes:
2017-Oct-21 • 47 minutes
Five Proven Methods of Levitation
Randy shows Jim five different ways in which a body can be levitated: by magnetism, by superconductors, by Lenz' Law, by acoustics, and most recently by thermophoresis. Show notes:
2017-Oct-04 • 50 minutes
Stochastic Electrodynamics
Randy explains Stochastic Electrodynamics to Jim, the theory that vacuum fluctuations are the cause of quantum mechanical behavior. Show notes:
2017-Sep-14 • 26 minutes
Exotic Photon Trajectories in Quantum Mechanics
Jim and Randy discuss strange trajectories observed in triple slit experiments with metallic plates. Photons seem to pass through one slit, come back through the middle slit, and out the third due to their interactions with surface plasmons. There are implications in this experiment about the way in which wavefunctions need to be interpreted in non-relativistic quantum mechanics. Show notes:
2017-Aug-20 • 41 minutes
A Gravitational Arrow of Time
Jim and Randy discuss a cosmological theory that purports to find an explanation for the arrow of time in gravitational theory based on the shape and distribution of matter and how it evolves. Show notes:
2017-Jul-16 • 37 minutes
Photonic Molecules and Optical Circuits
Randy tells Jim about photonic molecules, pairs of photons that create bound states like molecules do through a force mediated through an ultracold gas and similar ideas in optical circuits. They also discuss application of the same for quantum computing. Show notes:
2017-Jul-01 • 48 minutes
Requirements for Alternative Gravity Theories
In this episode Jim and Randy talk about how to evaluate alternative gravity theories. What sort of things do we want them to explain, what experiments do they have to predict, and what theoretical requirements do they have to meet. This is in some ways a continuation of Episode 9 - f(R) Theories of Gravity, but the discussion is relevant to all attempts to amend gravitational theory. Show notes: In the program, Randy talks about the outline I sent him. I put that up ...
2017-Jun-02 • 37 minutes
f(R) Theories of Gravity
Jim and Randy discuss gravitational theories that modify general relativity by changing the action using a polynomial dependence on the Ricci scalar. Although not physically motivated, some of these theories produce effects similar to those of dark matter, dark energy, and cosmological constants. Show notes:
2017-Apr-27 • 48 minutes
Vacuum Fluctuations and the Casimir Effect
Jim and Randy discuss how vacuum fluctuations produce the van der Waals forces and the Casimir effect. Van der Waals forces are factors in atomic bonds and the Casimir effect produces an attractive force between nanoscale objects. The claim is that vacuum fluctuations -- the production and annihilation of particle-antiparticle pairs -- are the underlying reason for both effects. Show notes:
2017-Mar-14 • 51 minutes
Virtual Gravitational Dipoles
Randy discusses what the Cosmological implications of a negative gravitational mass would be with Jim. If there were a negative gravitational mass (as opposed to inertial mass), then every time that an electron-positron pair was created in the vacuum, that would create a gravitational dipole. This in turn would create effects similar to dark matter, dark energy, and a cosmological constant -- and this in turn would have an effect on the origin of the universe. Show notes:
2017-Feb-14 • 50 minutes
General Relativity for the Experimentalist
Randy shares some of his favorite papers with Jim: papers on general relativity by engineer and science fiction author Robert L. Forward on how general relativity could be used in a terrestrial environment, including proposals for devices and materials. These papers are "General Relativity for the Experimentalist" and "Guidelines to Antigravity." Show notes:
2017-Jan-20 • 58 minutes
Pilot Wave Hydrodynamics
Randy and Jim discuss a physical analogy to quantum mechanics consisting of a droplet of fluid bouncing off of the waves in a similarly composed fluid that were generated by the droplet's own bounces. The analogy is very close to the de Broglie-Bohm interpretation of quantum mechanics. Show notes:
2017-Jan-05 • 48 minutes
Randy tells Jim about the emerging field of Phononics: using quantum particles of heat in materials for information processing in advanced materials. Show notes:
2016-Dec-06 • 41 minutes
Randy talks to Jim about gravitoelectromagnetism. Based on the similarity between Newtonian gravity and electrostatics, there should be a second gravitational field,the gravitomagnetic field. What are the implications of the existence of such a field, and how large are those effects? Show notes:
2016-Nov-15 • 31 minutes
The de Broglie-Bohm Interpretation of Quantum Mechanics
Jim talks to Randy about the pilot wave interpretation of quantum mechanics, which separates the particle and wave behavior of a non-relativistic quantum particle into that of a particle moving in and exciting a quantum mechanical medium. Show notes:
2016-Oct-31 • 44 minutes
G4V: Four Vector Potential Gravitation
Randy talks to Jim about Carver Mead's G4V, a formulation of gravitation combining the equivalenc...