Saturday, September 21, 2019

Wigner's Friend

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Recorded: 7/18/2019 Released: 9/21/2019

Randy tells Jim about an experiment that purports to have enacted a test of the Wigner's Friend argument -- one that Jim never really cared for. The experiment uses a double Aspect experiment to test whether non-quantum conclusions can be made from multiple experiments on entangled photons. This one is important: according to Wigner, your soul is at stake.
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Notes:

1. The papers we read for this program:

2. Other articles we discussed:


3. Related Episodes of Physics Frontiers:


4. Some books we mentioned:
  • Aharonov and Rohrlich, Quantum Paradoxes. (Review) An interesting depiction of quantum mechanics that introduces quantum phenomena by way of pseudo-paradoxes: things we think shouldn't happen, but do in quantum theory. This book was used for our first attempt at a podcast.
  • Bell, Speakable and Unspeakable in Quantum Mechanics. (Review) A selection of articles by John Bell, including those where he introduces his famous theorem that provided the impetus for the Aspect experiment.
  • Rae, Quantum Physics: Illusion or Reality?. I remember finding this to be an interesting popular book on quantum mechanics, and it's a Canto imprint -- one of my favorite book series.
  • Bars and Terning, Extra Dimensions in Space and Time (Review) Descriptions of the way high-energy theorists look at space and time, mainly in terms of string theory and symmetries, as I recall.
  • Mermin, Boojums All the Way Through. David Mermin's automemoirgraphy -- which is why I said his renaming Quantum Bayesianism as QBism was evidence of his mercurial personality.


5. Please visit and comment on our subreddit, and if you can help us keep this going by contributing to our Patreon, we'd be grateful.

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Friday, August 16, 2019

Loop Quantum Gravity

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Recorded: 6/13/2019 Released: 8/16/2019

Randy and Jim explore loop quantum gravity. Loop quantum gravity is a theory of space-time that emphasizes the random, pre-metric connections between points of a reasonably small size (the surface areas are on the order of the square of the Planck length) and the uncertainties therein.
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Notes:

1. The papers we read for this program:

2. Related Episodes of Physics Frontiers:


4. Carlo Rovelli has a very readable, and so far not too technical, introductory book on Loop Quantum Gravity, cleverly entitled Covariant Loop Quantum Gravity: an elementary introduction to quantum gravity and spinfoam theory. I think this is a pdf, if you want him to continue to live his monkish lifestyle.

5. Please visit and comment on our subreddit, and if you can help us keep this going by contributing to our Patreon, we'd be grateful.

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Monday, July 15, 2019

Spooky Action at a Distance

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Recorded: 5/2/2019 Released: 7/15/2019

Randy and Jim discuss the lower bound on the speed of communication within a wave function, and the limits associated with it.
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Notes:

1. The papers we read for this program:

2. Related Episodes of Physics Frontiers:


3. Related Episodes of PhysicsFM: Quantum Paradoxes:



4. The experiments in this podcast were based on Bell's Theorem, and if you're unfamiliar with it, you should check out The Speakable and Unspeakable in Quantum Mechanics, a collection of Bell's essays, which I review here. I also have discussions of The Wave Function and Quantum Sense and Nonsense, the first a philosophical and the second an advanced non-technical account of the same phenomena.

5. Please visit and comment on our subreddit, and if you can help us keep this going by contributing to our Patreon, we'd be grateful.

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Thursday, June 6, 2019

The Positive Energy Theorem

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Recorded: 12/9/2017 Released: 6/6/2019

Randy introduces a theory that purports to allow negative mass to Jim. It has been thought for quite a long time that negative mass was incompatible with general relativity, because it is possible to show that negative mass solutions are impossible. However Paranjape and his students noticed the proofs of this all relied on a flat background (zero cosmological constant). When trying to extend the theorems to a space with a negative cosmological constant, they found instead that negative mass is not prohibited.
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Notes:

1. The papers we read for this program:

2. Additional related paper for the positive energy theorem.:
3. Related Episodes of Physics Frontiers:



4. Details about just how well general relativity works can be found in Wills' Theory and Experiment in Gravitational Physics, whose work we reference in the podcast.

5. Please visit and comment on our subreddit, and if you can help us keep this going by contributing to our Patreon, we'd be grateful.

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Friday, May 3, 2019

Entropic Gravity

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Recorded: 4/4/2019 Released: 5/3/2019

Randy and Jim discuss Eric Verlinde's theory of emergent gravity that relies on statistical methods to produce both gravitational attraction and inertial effects.
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Notes:

1. The papers we read for this program:

2. Additional related paper I half-read and we discussed:
3. Related Episodes of Physics Frontiers:



4. Please visit and comment on our subreddit, and if you can help us keep this going by contributing to our Patreon, we'd be grateful.

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Sunday, February 24, 2019

The Chameleon Field

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Recorded: 11/3/2019 Released: 2/24/2019

Randy and Jim discuss the chameleon field - scalar field that mimics the effects of dark energy.
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Notes:

1. The papers we read for this program:

2. Related Episodes of Physics Frontiers:
  • Coming Soon



3. Please visit and comment on our subreddit, and if you can help us keep this going by contributing to our Patreon, we'd be grateful.

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