The Eternal Doorman

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...

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  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 ( ...

  Subscribe to GrowTree Organics . Subscribe to Crime Pays but Botany Doesn't . Video on Chalk: Life building mountains rather than skyscrapers:   See  Susan Stepney - Life as a Cyber-bio-physical System .  Subscribe to Rachel Philips .

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 ...

Testing. Check the size of this 50 character post. 

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...

The void here is apparently the Green P car park, on a rooftop in Kensington Market, Toronto. ?! See Laura Pausini - Turista (Official Video) . We need some Nihil Declarandum  here too. Get her new album at  https://laurapausini.lnk.to/iocanto2 . See Laura Pausini Announcing her New Album and Another World Tour . Subscribe to Laura Pausini . Original by Raf: Subscribe to Warner Musica Italia . I also saw this this morning. It's a Green Pod, for peas, ... They seem slightly desperate to me. I suppose it's only to be expected, the economy being what it is:  Subscribe to Maserati .

See  Alianza por la Solidaridad Andina - Voces Silenciadas, Espacios Reducidos .  Subscribe to Alianza por  la Solidaridad Andina . Tiffany Kimmel - Civil Service Interesting project, Nihil Declarandum . You wonder what the hell they're going to do next !: Nihil Declarandum is a creative company based in Highland Park, Los Angeles and the UK. Its mission is to create artist-driven works that tell uncomfortable truths, forgotten histories, and family secrets on a "need-to-tell" basis. Nihil & Friends designs and produces animated and live-action projects and events that are hand-crafted, emotional, and tactile. Subscribe to Dust and Nihil Declarandum .

I think of it as an advanced course in Security Engineering for Linux Users. See Security Engineering for Linux Users and Anti-Tempest Software and Pulp Fiction . Put together with Shadow TCP stacks in OpenBSD and  The T.H.E. Multiprogramming System Mk II  I dread to think what sort of thing the Internet could have become . Subscribe to Nir Lichtmann . 

What kind of knot are you? See Steven Strogatz on Mathematics, Biology and the Value of Simple Models  and Angela Collier's Funding Application . Subscribe to  Institut Henri Poincaré .

See Paronychia leucochthonicola (Caryophyllaceae: Paronychieae), a new species of the San Luis Valley, north-central New Mexico and adjacent Colorado by Cecilia Alexander . See her blog  and this post from 2011: Botany is hard .  So is being a Hernández's short-horned lizard . Fucking botanists! Imagine what it's like in a snowstorm up there. Doesn't bear thinking about. Subscribe to Crime Pays but Botany Doesn't . See also  Seven Year Study in Santa Fé NM Proves Native Plants Drought-proof Landscapes . 

The Atari 2600 cost around US$ 189 when it was released in 1977 and sold around 30 million units. The machine had only 128 Bytes of RAM memory and a 4KB ROM program memory on each cartridge. You can download a zip file containing a 4096 byte ROM image from https://www.atarimania.com/games/atari-2600-games-pitfall-14162 It runs in JavaScript in a web browser. Try https://javatari.org/?ROM=https://www.atarimania.com/2600/dumps/pitfall_cce.zip  It's too difficult for me! There is a user manual : You can disassemble the .a26 ROM images at https://www.masswerk.at/6502/disassembler.html . The reset vector for 6502 processor family is a 16-bit address stored at 0xFFFC and 0xFFFD: The 4KB ROM on the Atari 2600 is mapped at $F000-$FFFF even though the 6507 variant of the 6502 CPU had only a 13 bit address bus, it was internally the same silicon, so the 8KB of accessible memory was effectively mapped eight times through the full 16 bit (65KB) address space: Subscribe to VCF . Amazing ra...

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All running on a virtual machine which is in turn on an emulated Apple Macintosh, ... See https://hundredrabbits.itch.io/legs  and  Wireworld Automata . I hope that in here somewhere is a syntax and semantics for a DSL for succinctly describing Lego parts, ... from which the code to produce the 3D artifacts is automatically generated. Subscribe to Devine Lu Linvega . 

... and inspires a design for reducing flooding and urban heat-island effects in car parks, ...  See this Western Planner (2022) publication: Green Stormwater Infrastructure in a Semi-arid Climate: The Influence of Rain Gardens on Soil Moisture Over Seven Years by Aaron T. Kauffman. See Brad's books  (available in Spanish translations) and other projects at https://maearth.com/planttherain/grow . Subscribe to Brad Lancaster . Speaking of leave jokes, ... Leave Curious calling for beaver-bombers . See  The rise of ‘beaver bombing’ across Europe . See https://www.leavecurious.com/welcome . Subscribe to Leave Curious .

It's really good. He grew up in Bangalore in the eighties. See Two Great Talks on Programming Languages . 23:11 He has said before, in public, that his favourite syntax is raw-parenthetical. See https://pyret.org/ . They call it a scripting language, but it's actually self-hosted. I am not aware of many script languages that facilitate the writing of their own implementation. See  lang/src/arr/compiler/desugar.arr  for an example. 1:22:22 He makes an interesting point about models and soundness proofs. See Moshe Vardi talking about LTLf .  I am still amazed that people accept these undecidability results (where consistency is modelled by soundness in a representation) as if they say something about limits of human reason. See Intensional and Extensional Semantics in Programming Languages and Type Theory. Krishnamurthi has a scribble document instead of a blog: https://parentheticallyspeaking.org/ . They did a good interview with Philip Wadler a few months ago: Compare ...

This is a really great idea. I think she'd do it really well, and there's a lot of related stuff she could investigate. See e.g. A Statistical Model to Explain the Mendel–Fisher Controversy by Ana M. Pires and João A. Branco. Support her on Patreon . Subscribe to Angela Collier .

What a great commercial! See  https://music.futo.tech/  ... Subscribe to FUTO .

17:20 The only way humanity will be able to adapt to these ecological shocks is by freeing itself from the dependency on money.  22:45  This economic development is hamstrung by the bullshit of the IMF and the World Bank which are more concerned with maintaining the corrupt status quo than economic and human development.  Subscribe to Glenn Diesen . 

Why didn't Computerphile do a video on this? See Patrick Bahr - Safety First: How to Safely Disregard Unsafe Behaviour in Compiler Calculations and Attila Egri-Nagy on a Concatenative Logic Programming Language . 37:53 On going from small-step to big-step: see also  David Knothe and Oliver Bringmann - Combining Big and Small-Step Semantics to Verify Loop Optimizations . Papers: Calculating Compilers Effectively (Functional Pearl)  (2024) by Zac Garby, Graham Hutton and Patrick Bahr. Calculating Dependently-Typed Compilers (Functional Pearl) (2021) by Mitchell Pickard and Graham Hutton.  Calculating Correct Compilers II: Return of the Register Machines  (2020) by Patrick Bahr and Graham Hutton.   Calculating Correct Compilers  (2015) by Graham Hutton and Patrick Bahr. I once tried to get Richard Stallman and other GNU people interested in this sort of thing . It was around the time Calculating Correct Compilers was written. See GNU Thunder .  Subscri...