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