The Eternal Doorman

I've only seen 15 minutes of this but it looks like it's going to be a really great lecture. Who invented this stuff? (Thierry Coquand, Benjamin Pierce and David Turner, I think). Google suggests it was a bunch of people hacking on compilers in the 90s. It's funny how you can produce really pretty theories doing stuff like that, isn't it? It's as if there's a kind of implicit discipline of mechanism. There is a survey article here: Bidirectional Typing  by Jana Dunfield and Neel Krishnaswami. But note the remark at  1:02:35 . Maybe see 4.1. "Turning CCω Bidirectional" of Meven Lennon-Bertrand's PhD Thesis (2022): Bidirectional Typing for the Calculus of Inductive Constructions . I wonder if you can use this algorithm to derive custom type systems from programs, or is that too weird an idea?  See Girard, Lafont & Taylor's Proofs and Types , Section 3.3 on the significance of the Curry Howard Correspondence: This talk is a lot better than th...

It's not as bad as it sounds, if you're happy searching through megabytes of CSS definitions to find out who runs the State, ... See  Popper's Non-dualist Theory of Objective Knowledge  and John Searle on the Logical Structure of Human Civilization . The Drey Dossier .

I don't think this would be a problem for intelligent life. The question is, ...  From May 2022: SwRI-led team finds younger exoplanets better candidates when looking for other Earths  and  Mantle Degassing Lifetimes through Galactic Time and the Maximum Age Stagnant-lid Rocky Exoplanets Can Support Temperate Climates  by Cayman T. Unterborn, Bradford J. Foley, Steven J. Desch, Patrick A. Young, Gregory Vance, Lee Chiffelle, and Stephen R. Kane. Subscribe to  Anton Petrov . 

Subscribe to  Elle Cordova . See also Toby's video about the maths  Toby Reviewing Books - Liu Cixin's Remembrance of Earth's Past : Apparently I thought I understood some of this : 11:07 There's no violation of any facts , it's just that their entangled computers messed with our theorems, the first one being the no-communications one, ... that's really clever!😀  Our science would not be so hard to mess with! See Sheaf Theory, Probability and Topology .  Subscribe to Tibees .

This was a really great event they held in Ljubljana in March this year. See Nina Davies - Synchronising With Images and Martyna Marciniak : Subscribe to Aksioma .

See  Popper's Non-dualist Theory of Objective Knowledge  and the remark Popper made in 1977 about abstract invariants being causally efficient: I think that these considerations tell us a lot about natural selection. While Darwin still worried that he could not explain variation, and while he felt uneasy about being forced to look at it as chancelike, we can now see that the chancelike character of mutations, which may go back to quantum indeterminacy, explains how the abstract invariances of the environment, the somewhat abstract selection pressures, can, by selection, have a downward effect on the concrete living organism — an effect that may be amplified by a long sequence of generations linked by heredity. See Samson Abramsky's talk on Quantum Monads in  Martin Elsman - Deriving a Kronecker-Free Functional Quantum Simulator   where he explains the sheaf-theory approach to contextuality in Quantum Mechanics: See The Sheaf-Theoretic Structure Of Non-Loca...

In John Searle's 1998 lecture Social Ontology and the Philosophy of Society he said:  The question is: 'what is the ontology of social reality?' To begin with, I'm going to make an assumption which l won't justify today, though perhaps in tomorrow's discussion I can. The assumption is that we should abandon the traditional Western distinction between mind and body. We have in the Western intellectual tradition been cursed with this dualism, with the idea that there is a fundamental distinction between the mind and the body, between the mental and the physical. And in some respects the situation is made even worse by those philosophers who say that in addition to two worlds we also live in a third world. Philosophers such as Frege and Popper, and more recently Jürgen Habermas have said we should think of reality as dividing into three different worlds. My own view is we should never have started counting.  Popper's "three worlds" theory seems to ha...

She's beautiful and hilarious! Buy her and her sister's jewellery at  https://www.etsy.com/shop/Luxulite . Subscribe to Karolina Żebrowska .

It's a classic tragedy of the Commons situational logic: The Edwards Aquifer is the primary water supply for more than 2 million people across South Central Texas:  Subscribe to  Symbiosis Texas .  See What is Water Worth On the Free Market? Peabody Energy developed two coal strip mines on the Black Mesa reservation: the Black Mesa Mine and the Kayenta Mine. The company pumped water from the underground Navajo Aquifer for washing coal, and, until 2005, in a slurry pipeline operation to transport extracted coal 273 mi (439 km) to the Mohave Generating Station in Laughlin, Nevada. With the pipeline operating, Peabody pumped an average of 3 million gallons of water from the Navajo Aquifer every day. Subscribe to Spagoshi .

It's a really excellent talk given in December 2016: You can read McClintock's article here for now.  See https://www.denisnoble.com/ and Dance to the Tune of Life: Biological Relativity . See also Why is Physics So Difficult?  and also  William Jaworski on Hylomorphism  and Semantic Closure . Subscribe to Voices from Oxford . 

See  Susan Stepney - Life as a Cyber-bio-physical System .  My comment : This is interesting. I had never heard the term hylomorphism before, outside of computer science! Being in this sense is the higher ground in terms of which we abstract notions such as matter and energy which our senses could never perceive if it weren't structured. Reductionist science sees the problem upside-down: they wonder where is the structure, but ultimately the structure is the only thing we can actually understand. Think of the particle traces in cloud chambers or colliders at CERN. There is nothing to know about subatomic particles apart from the structure they were once a part of. At the end of a particle track you don't find the particle! See  https://williamjaworski.com  and his book Structure and the Metaphysics of Mind (Oxford University Press 2016) .  See also  John Searle on the Logical Structure of Human Civilization  and  Jacob Barandes' Talk at ESA Quantu...

See https://con.racket-lang.org/  and you can get a ticket at  https://www.eventbrite.com/e/racketcon-2026-tickets-1997181002140 . The live stream is publicly available, but buying this $10 ticket helps pay for the live stream and ensure its availability for the entire community. Subscribe to  Racket . It's fun. They have a corresponding amount (16 years or so) of cruft they need to deal with though: See Matthew Flatt's Sunday morning talk A New Foreign-Function Interface: ffi2 . Subscribe to  The Functional Cruft of Programming . I mean craft ! I am interested in the general problem, of how you build runtime systems and interfaces to existing code. I thought of using Standard ML modules to specify the interfaces in terms of something like GNU lightning, and then meta-programming the runtimes in the high-level language. I guess I could do this by writing a Standard ML #lang for racket, ... The GNU people weren't interested (see Graham Hutton, Zac Garby and Patrick B...

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I had a strange dream last night in which Euclid explained why he wrote his Optics as if "... visual rays proceed from the eyes onto objects, and that the different visual properties of the objects were determined by how the visual rays struck them." He said it's simply that geometry is the eye of God, i.e. that organ by which we know (i.e. determine ) where things are and what are their shapes etc. See  Martyna Marciniak . I forgot about this dream until I got to 21:45  where he mentions the measurement problem.  Subscribe to Jacob Barandes . 

I didn't get much of this!  See nlab on  Diaconescu-Goodman–Myhill theorem and Wikipedia's  Diaconescu's theorem . My comment :    11:05 FYI I found this very hard to follow. Actually it has so far been impossible for me to follow! I don't know the context of these statements like "a predicate of booleans is a function from bool (Boole?) to prop" I can guess that it means a well-formed formula with a parameter P, say, which when substituted with any well-formed boolean-valued expression produces a well-formed statement of a proposition, i.e. just another boolean-valued expression? But it could also be interpreted extensionally in set theory and the result would be completely different. So what is the sense in which these things are equivalent? The only way I can see to make this meaningful is to restrict to a language where you speak only of how these translations are made. To talk about sets and types as if they exist independently of this seems like mad...

I think it might just be another kind of headache she's made, ... My comment : I'm glad you could do this, but I just wish the ordinary calendar app on your phone could do it. A tracker is just an interface and a tagged data type in the events (headache, cake, sunny day etc.). Lot's of people need different interfaces to their calendars for lots of different reasons, and if it was really a calendar app it would let you do this, but the calendar app is not that, it's just one tiny part of what a calendar could be. The problem is that the AI probably wrote a brand new calendar data format and keeps separate database, etc, etc, [but maybe not: see Android Calendar Provider API ] and the other problem is that it probably wrote a whole lot of Java/ Kotlin whatever and when something changes or you want to change the app what do you do? Next time you want to use AI to modify the program it may be more difficult because you have to tell the AI about what the last AI did and w...

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See Dennis Rediscovering an Overcast Stitch Binding Method for Loose Leaf Books . See his Patreon page for the endpapers and typesetting.  Subscribe to Four Keys Book Arts .

It's her birthday, and this about her journalism career.   See her Patreon: https://www.patreon.com/rachelblevins . And she did an interview with Richard Wolff where he talked about wiggle room: See USS Abraham Lincoln crew visits Thailand’s Pattaya, in photos : See also the Newsweek piece: USS Abraham Lincoln Photos Reveal Warship’s Condition As It Makes Port . Subscribe to Rachel Blevins .

See  Kovalevskaya Top at IWF (Göttingen)  and the Wikipedia page:  Lagrange, Euler, and Kovalevskaya tops .  See Mura's series on Sofya Kovalevskaya's autobiography : See  Mura Yakerson's Upcoming Series on Sofya Kovalevskaya .  Subscribe to Math-life Balance .

This is a great lecture. He makes the same jokes he was making in 1998, but he clearly enjoys telling them. See Social Ontology and the Philosophy of Society . It's quite a claim though, that this applies to all of human civilization.  I suppose one could just declare this to be the case in some appropriate context, ... but which one? 46:52 . His answer to the question at 59:06 seems to me to put particles such as protons and electrons fairly squarely into the category of products (i.e. theories) of social institutions: they are produced by people who have machines the development and manufacture of which are funded at least in part by income tax! You need to have been immersed in a very peculiar (I can't say  particular ) culture to have even a vague notion of what a proton or an electron are. See Jeremy Narby - Intelligence in Nature .  Subscribe to Philosophy Overdose .  

It's another good one. Lots of history I didn't know and some figures about BRICS representation in terms of economic production and population. See Paulo Nogueira Batista Jr. interviewed by Nima Alkhorshid . 27:34 When the Soviet Union was dissolved Russia took on all of the legal obligations the USSR had entered upon. I presume that included the nuclear agreements which the US backed out of. Subscribe to Glenn Diesen .

My comment : Oh wow, if you work for one of these companies then watching this is like seeing your underpants being taken off and shown on TV!  See  Sylvain Huet - Bare Metal Made Easy and https://github.com/nmatt0/moria   https://github.com/nmatt0/mithril   More about the tools: Subscribe to Matt Brown .

They were able to buy these things for around $200 and enable 64GB of HBM2e memory and 200 TFLOPS of FP16 tensor compute on the CMP 170HX. Subscribe to  media.ccc.de

Not that easy,... See  Programming Paradigms ,  David Evans, Vladimir Kolesnikov and Mike Rosulek - A Pragmatic Introduction to Secure Multi-Party Computation  and  FUTO FUBS .  See  the Hackaday article  and these pages: https://minimacy.net/ https://www.sylvain-huet.com/ If you are interested to know what your 10Gb Ethernet router is doing on the wire, you will need something like  http://fireless.cs.cornell.edu/sonic/faq.php . Subscribe to Hackaday . 

You can get Calibán y la bruja: mujeres, cuerpo y acumulación originaria  by Silvia Federici from the Internet Archive, or in print from Tinta Limón press . She's going on tour soon. See https://linktr.ee/pupinaplomer . Subscribe to Pupina Plomer .

See the book at  https://securecomputation.org/ There are some interesting case studies in Chapter 1 . Here's the article by Yehuda Lindell: https://cacm.acm.org/research/secure-multiparty-computation/ See Paulo Nogueira Batista Jr. interviewed by Nima Alkhorshid .  Subscribe to  Association for Computing Machinery . Raspberry Pi are making an effort, albeit a bit of a half-arsed one ( 16:43 ) responding to legislation with 'industry partners': Subscribe to Raspberry Pi .

It's a good technique for binding single sheets rather than folded signatures, for example you could use this to bind full-size output from an ordinary A4/letter laser printer. Here are some improvements to the method:  Subscribe to Four Keys Book Arts .

He's refreshingly positive. He thinks there are no great obstacles to a global "economic communications system" and a trans-national global reserve currency ( 32:55 ). All it needs are the central banks to stop toeing the IMF/World Bank/BIS line. I think once you have a half decent telecommunications system you won't even need a notion of a global reserve currency. That is what Britain and the US are fighting. See Kim Iversen interview with Richard Grove  and American Life . On PIX see Fabiola on The House Fire at Lago Amanã .  It's strange that the title of the Spanish translation of Hernan Diaz's novel Trust is Fortuna . His first language is Spanish but he writes in English. See this interview in El Pais with Diaz:  The inventor of capitalist realism is an Argentine who writes in English . The English and Spanish together can really fuck up some words!  Subscribe to Dialogue Works . Glenn Diesen interviewed Chas Freeman around the same time. He thinks ( ...

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This is interesting, but it is a bit depressing. If even one quarter of this is true, you can see why people might find it difficult to establish a secure, reliable telecommunications system. Richard Grove is a part of the Grand Theft World podcast . Subscribe to Kim Iversen .  See also  Angela Collier's Book Chat with Alan Melikdjanian . 

This is interesting. See  Martyna Marciniak  and  Semantic Closure . I found this talk whilst looking for Robert Rosen's posthumously published 1991 book Life Itself - A Comprehensive Enquiry into the Nature, Origin and Fabrication of Life . Here is a well-written review by Sarah Voss. See also Robert Rosen’s Relational Biology Theory and His Emphasis on Non-Algorithmic Approaches to Living Systems by Patricia A. Lane. It's quite sane, but I think I could help with the meta-dynamics of open systems ( 31:20 ) In short, the meta-dynamics of the open system is effectively the embodiment of the organisms' own cognitive system in its environment, so it's a shared interlocking and interdependent phase space. That is why I have so much trouble with the ideas of Levin and his followers who plug living tissue into a neural network and then select for certain behaviour they think will attract funding or attention or something, and it's invariably in very poor taste. See als...

It's a really great discussion about the novel Trust by Hernan Diaz . It sounds good, but really complicated. I can imagine needing to write notes to be able to figure out what I'm supposed to be reading and if I was doing that I might as well be trying to explain quantum mechanics or something. However, this does remind me a bit of The Blazing World by Siri Hustvedt, which I really enjoyed. Apparently (though not to me, I only just read this in another review ) the title is a reference to Margaret Cavendish 's novel  The Description of a New World, Called The Blazing-World . Subscribe to Angela Collier .

Great talk about open source and FSF politics. See  https://gpg.fail/  and  To sign or not to sign: Practical vulnerabilities in GPG & friends .  19:50 Janitors that are too important to waste their time doing anything better than they already do it. That's not to say that rewriting  garbage in rust is a better thing to do! Don't write garbage! See  Sukyoung Ryu - Programming Language Research for Technical and Social Good (KAIST) .  Talk from December last year: Subscribe to  media.ccc.de . 

This is really interesting. She explains how, through self-reference, she became the Pope. At least that's how I imagine López-Díaz and Gershenson would put it (see Semantic Closure ). See  Emanuele Tesauro's ' Il cannocchiale aristotelico ' : 15:33  What she is referring to by the phrase pre-optical notions of vision is, I think, ideas such as that of  Extramission , which seems to have been entertained by Euclid in his Optics ! I think the quote of Stanisław Lem she is referring to at  30:00 is this passage from Summa Technologiae , specifically the chapter Intelligence: An Accident or a Necessity? : When it comes to changes that would knock an organism out of its environmental equilibrium by “programming” some unforeseeable instincts into it, the answer of the “first-order regulator” turns out to be unsatisfactory—which results in a crisis. On one hand, the mortality of non-adapted organisms suddenly increases, while at the same time, selection pressure privileg...

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See Closing the Loop: How Semantic Closure Enables Open-Ended Evolution?  by Amahury J. López-Díaz and Carlos Gershenson.   I found this sentence quite striking: "This manuscript explores the evolutionary emergence of semantic closure—the self-referential mechanism through which symbols actively construct and interpret their own functional contexts, ..." The paper has apparently been accepted for publication in the Royal Society's journal Interface . One wonders what these little symbols could be getting up to while mathematical biologists aren't paying attention, ... I suppose we should ask Steven Wolfram . See  Martin Elsman - Deriving a Kronecker-Free Functional Quantum Simulator . That talk Samson Abramsky gave in 2012 was really thought-provoking:   In particular A computable expression of closure to efficient causation by Matteo Mossio, Giuseppe Longo and John Stewart. The question about self-representation in total functional programming is an interestin...

See the paper Deriving a Kronecker-Free Functional Quantum Simulator .    17:22  How hard it is to find comprehensible surveys in this field. Reply by Samson Abramsky.   There was also a talk by Martin at ICFP 2026 ( 7:41:22 ) but they forgot to charge the microphone or something. However it's audible from 7:55:13 . Samson Abramsky on Quantum Monads 8:00  On relations and graph isomorphisms: the Heisenberg-Weyl algebra is a special case of generic graph rewriting.  See The algebras of graph rewriting by Nicolas Behr, Vincent Danos, Ilias Garnier and Tobias Heindel. I wonder how much proof theory can fit into this framework of isomorphism classes of graph-rewriting systems. See for example Sequent calculi for a unity of logic by Norihiro Yamada..: "Classical logic is the logic that permits unrestricted premise consumptions and reasoning do-overs , and is unaware of either".  See  The Sheaf-Theoretic Structure Of Non-Locality and Contextuality ...

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This is a really inspiring talk given at The NSF-Simons National Institute for Theory and Mathematics in Biology in June [2025]. See Arthur Winfree's 1980 book The Geometry of Biological Time .     See also  Anton Petrov on Ultra Weak Biophoton Emission and Time Crystals . Subscribe to  NITMB Chicago . I'm reposting this, from a year or so ago, because of the Institut Henri Poincaré thing this morning which asked "What kind of knot is a person?" and it really made me think. Especially, it reminded me of this idea of Algebraic Automata theory . I had never heard of that, but it is about as old an idea as Automata theory itself. See Attila Egri-Nagy on a Concatenative Logic Programming Language .  It seems that lots of things, like knot theory and automata theory, for example, are only accidentally in different categories: if history had been otherwise, then maybe we would have sliced it all up quite differently and we would be amazed by theorems relating knots...