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]

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