An Excellent Talk about Computability and Hilbert's Entscheidungsproblem

He calls it the entschuldigungsproblem though. 

My comment:

7:15 Jenann Ismael gave a talk at Johns Hopkins last year entitled "Cracks in the edifice of determinism" where she argues that this sort of self-reference produces questions which have no meaningful answer. There then arises the question as to how much one can reasonably deduce about physical processes (such as computation) based on their demonstrated inability to answer such questions.


See Jenann Ismael - Laplace meets Godel: How Self reference Foils Prediction for more details and a suggestion as to a better way to define "effectively calculable" that does not depend on our incomplete knowledge of physics. 

Subscribe to Computable Secrets.

Subscribe to Hopkins Natural Philosophy Forum. 

See Dana Scott on Lattice Fixpoint Semantics and Gopal Gupta on Logic, Co-induction and Infinite Computation.

On Monday, Aug. 29, 2016 in Berkely, Dana Scott gave a lecture on a model for stochastic lambda calculus:


34:40 On the question of "What is an algorithm?" He refers to discussion by Yiannis Moschovakis on the FoM list around 2016.  This list was for some time policed by Martin Davis. In 1958 Martin Davis published his book Computability and Unsolvability:

The problem with this position (the existence of absolutely unsolvable problems) is that one needs to produce a coherent argument that the definition of the diagonalised self-referential "loop detector" is in fact "completely precise", because it is manifestly not!

44:33 The question of what a stochastic operational semantics could be is interesting.  

48:42 About Helmut Veith who died tragically on March 12, 2016. I think that's how Robin Milner's wife Lucy died, and Robin died the same weekend. Robin was a research assistant at Stanford. See Implementation and applications of Scott's logic for computable functions.

Subscribe to Simons Institute for Theoretical Computing.

See Niccolò Veltri - Type-Theoretic Constructions of the Final Coalgebra of the Finite Powerset Functor and for some tips on navigating unkind epistemic environments: About Logic with Seunghyun Song and Jordi Fairhurst.

Comments

Post a Comment

Popular posts from this blog

Steven Johnson - So You Think You Know How to Take Derivatives?

Image
A derivative is linearisation, and differential calculus is essentially linear algebra, ...  See  Freya Holmér - Why Can't You Multiply Vectors?  and  Freya Holmér on Continuity of Splines . See also the MIT OCW page:  Matrix Calculus For Machine Learning And Beyond  (Alan Edelman, Steven G. Johnson) Subscribe to The Julia Programming Language . Alan Edelman talking about expressing mathematics as computer code. The idea is that you can use computer languages to communicate mathematical ideas precisely to other people. See my comments about functional programming languages here:  https://prooftoys.org/ian-grant/hm/ Subscribe to TEDx Talks .
Read more

Hitachi HD44780U LCD Display Fonts

Image
I finally got the bit-mapped fonts from the Hitachi "1602" display :  Here's some JavaScript: const HD44780U01ASCII=[ [],[],[],[],[],[],[],[],[],[],[],[],[],[],[],[], [],[],[],[],[],[],[],[],[],[],[],[],[],[],[],[], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, ], [4, 4, 4, 4, 0, 0, 4, 0, 0, 0, ], [10, 10, 10, 0, 0, 0, 0, 0, 0, 0, ], [10, 10, 31, 10, 31, 10, 10, 0, 0, 0, ], [4, 15, 20, 14, 5, 30, 4, 0, 0, 0, ], [24, 25, 2, 4, 8, 19, 3, 0, 0, 0, ], [12, 18, 20, 8, 21, 18, 13, 0, 0, 0, ], [12, 4, 8, 0, 0, 0, 0, 0, 0, 0, ], [2, 4, 8, 8, 8, 4, 2, 0, 0, 0, ], [8, 4, 2, 2, 2, 4, 8, 0, 0, 0, ], [0, 4, 21, 14, 21, 4, 0, 0, 0, 0, ], [0, 4, 4, 31, 4, 4, 0, 0, 0, 0, ], [0, 0, 0, 0, 12, 4, 8, 0, 0, 0, ], [0, 0, 0, 31, 0, 0, 0, 0, 0, 0, ], [0, 0, 0, 0, 0, 12, 12, 0, 0, 0, ], [0, 1, 2, 4, 8, 16, 0, 0, 0, 0, ], [14, 17, 19, 21, 25, 17, 14, 0, 0, 0, ], [4, 12, 4, 4, 4, 4, 14, 0, 0, 0, ], [14, 17, 1, 2, 4, 8, 31, 0, 0, 0, ], [31, 2, 4, 2, 1, 17, 14, 0, 0, 0, ], [2, 6, 10, 18, 31, 2, 2, 0, 0,...
Read more

RISC-V Peripheral Idea - A High-Speed LVDS Link for a Modern Transputer

Image
Thinking about the  TinyTapeout RISC-V Peripherals  experiment: That  Pico ICE FPGA Trainer Board  will be able to prototype a high-speed serial bus interconnect which could also be the basis for a RISC-V CPU peripheral that would be the moral equivalent of a Transputer serial-link. Each node could be a RISC-V with four links to its neighbours. LVDS drivers like the Analog Devices ADN4665 and ADN4666 , connected via low-cost SATA cables. The hardware could handle the  8b/10b encoding  and interface to DMA channels, which would be another peripheral that would probably be quite a severe test of the project infrastructure, but for the prototype the FPGA could probably be interfaced with the RP2040's DMA somehow, even if it was just via GPIO pins. There is even a Lattice Reference design for an 8b/10b encoder that you could download and drop-in.   45:31 "Is it still relevant?"  Subscribe to CSS Bristol . Then YouTube turned up this 2018 talk by...
Read more