The Eternal Doorman

This is a really clever bit of video and careful sound editing. See the video description . Subscribe to  LOUNISPHOTOGRAPHY®

I had never heard the term psychophysics until a minute ago! It's about the objective  perception of physical effects. The idea is that, although perception is inherently subjective, one can measure the sensitivity of subjects to physical effects and form a notion of normal perception statistically. This is then objective in the sense that it gives expectations of any individual subject's ability to discriminate between different levels of some particular stimulus, such as the amplitude of a sound or vibration of a certain frequency. See  Weber–Fechner law  and  Stevens' power law . Both Weber's law and Fechner's law were formulated by Gustav Theodor Fechner (1801–1887). They were first published in 1860 in the work Elemente der Psychophysik (Elements of Psychophysics). This publication was the first work ever in this field, and where Fechner coined the term psychophysics to describe the interdisciplinary study of how humans perceive physical magnitudes. He mad...

David's Guitars (The Afterparty) It's hard to understand why every guitarist isn't quite a fan of Roy Buchanan. Maybe it's rare though for someone to listen to someone that good and not immediately just give up trying to play the guitar! See  Colleen Fazio on the Music of Roy Buchanan . Subscribe to David Gilmour .

 Full album stream tomorrow at 6 PM, ... Here's The Making of, part 3: Subscribe to Nick Cave & The Bad Seeds .

Here's my comment: I studied an undergraduate course based on Sutherland's book An Introduction to Metric and Topological Spaces . For some reason I really liked that book, but I never understood what the course I was studying was actually supposed to be about. It was just a bunch of proofs of theorems that seemed kind of random to me. Like we were just making these definitions and proving theorems about them without having any real goal. Since then I've started to see that what it is really about is analysis on sets and Poincaré's and Dirichlet's attempts to make this rigorous. But the course I did didn't have any of this historical context, so it just seemed like a vague association of disconnected ideas all called "topology" and not always for the same reasons! The other day I saw a really interesting Biography of Poincaré in a bookshop. It may have been this one:  Henri Poincaré: A Scientific Biography  by Jeremy Gray . The course I studied was  Op...

See also Penelope Maddy's lecture on mathematical reality in Daniel Tubbenhauer on Computer Aided Mathematics . What I don't understand is why there is so much more mainstream academia effort going into "new research" and so little into effective teaching. See Teaching People How To Design Programs and How To Code and David Hestenes - Tutorial on Geometric Calculus . Subscribe to Theories of Everything with Curt Jaimungal .

There is this quite good EdX course developed by Gregor Kiczales, Professor of Computer Science at the University of British Columbia. It's called  How to Code: Simple Data  and it uses Racket and various modules from the book  How to Design Programs  by Matthias Felleisen, Robert Bruce Findler, Matthew Flatt and Shriram Krishnamurthi. See this:  Review: Introduction to Systematic Program Design – Part 1  and for more on HtDP, see  Felleisen, Findler, Flatt, Krishnamurthi (Journal of Functional Programming) The Structure and Interpretation of the Computer Science Curriculum . The method consists in writing a carefully selected number of concrete test cases as examples of basic constructions and then using them to test the fully abstract representation. The approach seems, to me, to be almost total functional programming with dependent types. See  Checking Dependent Types with Normalization by Evaluation: A Tutorial  by David Thrane Christia...

Subscribe to Tibees^2 . Roger Penrose talking to Brian Keating about that book Toby had never heard of, ... Brian interviews some of the finest minds in the multiverse.: Subscribe to Brian Keating .

The description of the Tayloe detector is interesting, even if you have no plans to make one of these things. See  http://www.norcalqrp.org/files/Tayloe_mixer_x3a.pdf . Part 2: Subscribe to 101 Things . Gary Explains RP2350 - Pi Pico2 CPU Subscribe to Gary Explains .

See also  Amanda Gefter on John Wheeler and Peter Putnam . Some of her slides: 1:11:30   "Any world that all observers agree on is essentially independent of any one particular observer." But if any one particular observer had not been a participant in that world then it is hard to see how the world that the others observe would be the same as that one they all agree upon: for example it would not contain that putative missing observer! This is the essence of holism, I think. We (as scientists) only know the world by slicing it up (with laboratory apparatus) and discussing our observations in some language through which process we attempt to achieve coherent descriptions of these different ways of slicing the one whole world into pieces. In quantum mechanics the language we use does not allow us to describe that process of slicing itself, only the resulting phenomena we experience. Subscribe to  IQOQI Vienna .

See  https://leanprover-community.github.io/undergrad.html and  Solution of the Robbins Problem by William Mccune. Subscribe to Visual Math . So much for the existence of proofs. There is also a very similar problem in the philosophy of mathematics concerning the existence of numbers, sets and such-like. And problems in metamathematics concern the validity of reasoning about correspondences between proofs and mathematical objects. All of these seem to me to be questions about languages and about translations between those languages. Penelope Maddy on Objectivity in Mathematics Subscribe to  Penn Videos

Of course this will probably be used to justify creating even more high-level radioactive waste. See  Sabine Hossenfelder Ripping The Seat out of Mark Andreessen and the Techno-optimist Bros' Pants . Subscribe to Sabine Hossenfelder .

She does it very well. Andreessen is a browser engineer who broke free from his chains. See  Eron Woolf and Andreas Kling Talking About the Ladybird Web Browser . Not everything in that manifesto is stupid, but the problem is that judging by what technology we have now there is no reason to believe that technology will not create more and worse problems than it solves. I agree with Sabine that it's knowledge that is more important. So I think technology for developing and communicating ideas would be a good start, ...  Subscribe to Sabine Hossenfelder . Look, we can't even make web pages that collect data from a form and email it to someone: I don't know that it's a good idea to employ anyone to write perl code for anything. I think it's kludges like perl and CGI that are the cause of a great many problems.

This is a truly brilliant talk! Some screenshots below. See also  Amanda Gefter on John Wheeler and Scientific Reality . Subscribe to Chris Fuchs . 33:50 There is a kind of summing up, by Wheeler, of the connection between Wheeler's and Putnam's points of view.