The Eternal Doorman

See  Probability in many-worlds theories by Anthony J. Short : We consider how to define a natural probability distribution over worlds within a simple class of deterministic many-worlds theories. This can help us understand the typical properties of worlds within such states, and hence explain the empirical success of quantum theory within a many-worlds framework. We give three reasonable axioms which lead to the Born rule in the case of quantum theory, and also yield natural results in other cases, including a many-worlds variant of classical stochastic dynamics.   See also  Mark Jago on Type Theory in Computer Science, Logic and Linguistics  and Robinson Erhardt - Tim Maudlin & Jacob Barandes: The Indivisible Approach to Quantum Theory .  Subscribe to Dr Maria Violaris .

First an introduction: My comment : This is great! For a long time I have been thinking that someone (I guess it's me!) should produce a system that allows people who are studying these different logical formalisms to fairly easily write formal descriptions of translations from one to the other and also to formally prove things about the translations and maybe about these translation processes themselves (You would want a very expressive system like HoTT with Univalence to do this though. See Voevodsky's comment at 2016 Heidelberg Laureate Forum "... it came out, as a result of practical work on formalization we just discovered that the law of excluded middle and axiom of choice can be avoided in the univalent foundations much more successfully than they can be avoided in set theory, so things which can not be done without them in set theory can be done without them in the univalent foundations, so then there was this understanding that the classical mathematics appears as...

It's really great to see how all the maths was developed and how the physical theories followed. Often it seems that it was the mathematical developments that gave the physicists the ideas about which models would yield solvable equations! See  Jorge Diaz on Heisenberg's "Über quantentheoretische Umdeutung kinematischer und mechanischer Beziehungen"  and  Robinson Erhardt - Tim Maudlin & Jacob Barandes: The Indivisible Approach to Quantum Theory . These two fill in some more gaps: In this one we get a look ( 7:45 ) at how Dirac "unified" the Heisenberg and Schrödinger pictures. See  Gabriele Carcassi on Why Statistical Mechanics is Fundamental in Physics :   See also his recent short essay:  How fundamental physics progresses . I looked into his claim that Maxwell's electrodynamics followed from a mathematical inconsistency in Ampere's law. That may be what actually happened, but it is hard to say whether the inconsistency was purely mathematica...

Watch right through to the end, ... in 2013 there was a near miss in almost identical conditions, an inquiry was conducted and a recommendation made to close that Helicopter route, but the FAA took no action. See  The Evolution of Air Traffic Control Procedures . One of the NTSBs findings was that there were inadequate mechanisms for sharing information between the different agencies involved. They don't have FaceBook pages then? How come? Dan has a film production company called Serendipitous: see  https://s-films.com/about/ Subscribe to Taking Off .

This is a bit short on science, but interesting: see  New science in plain sight: Citizen scientists lead to the discovery of optical structure in the upper atmosphere : A glowing ribbon of purple light running east-west in the night sky has recently been observed by citizen scientists. This narrow, subauroral, visible structure, distinct from the traditional auroral oval, was largely undocumented in the scientific literature and little was known about its formation. Amateur photo sequences showed colors distinctly different from common types of aurora and occasionally indicated magnetic field–aligned substructures. Observations from the Swarm satellite as it crossed the arc have revealed an unusual level of electron temperature enhancement and density depletion, along with a strong westward ion flow, indicating that a pronounced subauroral ion drift (SAID) is associated with this structure. ...  And without FaceBook it would never have happened! Subscribe to  Real Storie...

She's quite good at it, ... Subscribe to Kim Iversen .

This is a really good discussion. Far better than any interview I've seen someone try. 1:08:09  On the positivist's principle of instrumentalism. Here they are talking about Sydney Shoemaker's "thought experiment" (it's not an experiment that in principle could actually be done) described in his 1969  Time Without Change . 1:22:32  On the historical development of Quantum Mechanics see  Jorge Diaz on Heisenberg's "Über quantentheoretische Umdeutung kinematischer und mechanischer Beziehungen" . See also his video below on Hamilton-Jacobi mechanics for more details on Barandes' comments. 2:29:40 On decoherence and measurement, seeMaudlin's  Three measurement problems  ( pdf here if you're lucky ). 2:34:48 On probability see Maudlin's 2007  What could be objective about probabilities? On the derivation of the Foldy-Wouthuysen transformation of quantum states: see Harvey Brown  Aspects of Objectivity in Quantum Mechanics . Subscribe...

There was an ACM SIGPLAN ICFP track called ML'23 apparently. 20:47 It's a pity that they couldn't have worked on MLRisc a bit more: this was in 1994! " CPS is compiled to a tree language called MLRISC; intended in part, to describe the simplest kinds of operations implementable in hardware. No assumptions are made regarding addressing modes or types of instructions, and because of our register allocation scheme, there are few assumptions made about physical registers. The MLRISC is then converted to a flow graph of target machine instructions, which is optimized using generic optimization modules parameterized over a machine description . ... The new code generation strategy is implemented using an SML version of iBurg "  It was only 20% slower than code generated by the LLVM backend. See  A New Backend for Standard ML of New Jersey .   He also did a talk on the Pretty Printer system: I think the way to deal with this is to recognise that pretty-printing is jus...

This is about a paper published in 1991:  Functional programming with bananas, lenses, envelopes and barbed wire  by Erik Meijer, Maarten Fokkinga & Ross Paterson. Other references to articles and papers by Milewski , Wadler and Gibbons at 32:48 . I also came across this paper by Wadler:  The Girard-Reynolds Isomorphism . I wish I had known about this, it would have saved me several years of work! Mike Gordon presumably didn't know about it either: see Emily Riehl and Terrence Tau on The Future of Mathematics . Subscribe to  Lambda World . And I just found this 2016 ICFP talk by Dan Licata on Functional programming and Homotopy Type Theory. At 45:54 there is an example of taking this idea of higher inductive types to verify interpreters. Subscribe to ICFP . This was  given in 2019. See  Cubical Agda: A Dependently Typed Programming Language with Univalence and Higher Inductive Types : The principle of univalence is the major new addition in Homotopy...