# Physics Frontiers

## Science >

## Episodes

## Post-Newtonian Gravitation

6/8/2018

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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

Duration:00:41:47

## The Consistent Histories Interpretation of Quantum Mechanics

5/24/2018

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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

Duration:00:45:59

## Gravitational Alternatives to Dark Energy

5/15/2018

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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

Duration:00:46:56

## The Quantum Vacuum and the Casimir Effect

4/24/2018

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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

Duration:00:41:21

## The Gravitational Equivalence Principles

4/14/2018

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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

Duration:00:46:05

## Antimatter Production at a Potential Boundary

3/25/2018

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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

Duration:00:39:32

## Gravitational Field Propulsion

3/15/2018

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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

Duration:00:58:00

## The Island of Stability

2/23/2018

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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: http://frontiers.physicsfm.com/24

Duration:00:25:27

## Dark Energy

2/8/2018

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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: http://frontiers.physicsfm.com/23

Duration:00:45:55

## Weyl and Quasiparticles

1/21/2018

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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: http://frontiers.physicsfm.com/22

Duration:00:37:01

## The Origin of Inertia

1/10/2018

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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: http://frontiers.physicsfm.com/21

Duration:00:38:47

## Time Crystals

12/21/2017

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Jim talks to Randy about structures that are periodic in time like crystals are periodic in space. Show notes: http://frontiers.physicsfm.com/20

Duration:00:34:19

## The 2T Physics of Itzhak Bars

12/6/2017

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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: http://frontiers.physicsfm.com/18

Duration:00:44:54

## The Physics of Time Travel

11/24/2017

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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: http://frontiers.physicsfm.com/17

Duration:00:43:39

## Stochastic Resonance Energy Harvesting

11/6/2017

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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: http://frontiers.physicsfm.com/16

Duration:00:37:40

## Five Proven Methods of Levitation

10/21/2017

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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: http://frontiers.physicsfm.com/15

Duration:00:47:03

## Stochastic Electrodynamics

10/4/2017

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Randy explains Stochastic Electrodynamics to Jim, the theory that vacuum fluctuations are the cause of quantum mechanical behavior. Show notes: http://frontiers.physicsfm.com/14

Duration:00:47:36

## Exotic Photon Trajectories in Quantum Mechanics

9/14/2017

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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: http://frontiers.physicsfm.com/13

Duration:00:26:19

## A Gravitational Arrow of Time

8/20/2017

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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: http://frontiers.physicsfm.com/12

Duration:00:41:21

## Photonic Molecules and Optical Circuits

7/16/2017

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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: http://frontiers.physicsfm.com/11

Duration:00:36:46