Physics Frontiers

Jim talks with Daniel Whiteson of the University of California at Irvine about his new book _Do Aliens Speak Physics,_  In this discussion we look at his "extended Drake equation that asks, "if aliens do exist, will we be able to talk to them?"  Or learn anything from them.Show Notes: http://frontiers.physicsfm.com/83(May be delayed)

Jim talks with Koustubh Phalak about quantum random access memory (QRAM), a proposed technology that would allow the storage of quantum states in qunatum computation.  Koustubh discusses quantum computing, the need for QRAM, proposed implementations of QRAM, and some of the difficulties in its implementation.Show Notes:  http//frontiers.physicsfm.com/82

Jim talks with Philip Tee about the effects of a fundamental length scale.  Phil uses doubly special relativity to try to find observable effects of the pixelization of space, including its effect on light bending and the Casimir effect.Show notes: http://frontiers.physicsfm.com/81

Jim talks with Philipp Strasberg about his simulations of branching and recombining processes in the evolution of quantum states, and their meaning for not only for the many worlds interpretation but also for understanding quantum mechanics in general.Show Notes: http://frontiers.physicsfm.com/80 

Jim talks  with Elba Alonso-Monsalve and David Kaiser about the prospects to describe dark matter as tiny black holes that were created at the end of cosmic inflation.  Due to the large inhomogeneities in the distribution of matter at that time, the black holes could form directly from the matter distribution and not be color neutral (in the sense of QCD).Show notes: http://frontiers.physicsfm.com/79 

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 Claus Kiefer about the implications of Goedel's incompleteness theorems on the search for the theory.Show Notes: http://frontiers.physicsfm.com/76

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

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 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 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 interpretation in light of quantum gravity.Show Notes: http://frontiers.physicsfm.com/72

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.

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!)

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 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]