tim_hutton | 2 years ago | on: 'Mathematically perfect' star system being investigated for potential alien tech
tim_hutton's comments
tim_hutton | 2 years ago | on: Ed Fredkin has died
Fredkin’s Self-Replicating Cellular Automata:
Sum the neighbors, modulo 2, and assign to the cell on the next timestep.
Astonishingly this allows patterns to replicate in multiple directions across the plane. https://cellpylib.org/fredkin.html
Works with any kind of lattice. Even works in 3D.
tim_hutton | 2 years ago | on: Ed Fredkin has died
"According to biographer Robert Wright, the character Stephen Falken in the film WarGames was modeled after Fredkin." [https://en.wikipedia.org/wiki/Edward_Fredkin]
tim_hutton | 2 years ago | on: The role of cat eye narrowing movements in cat–human communication (2020)
Did you know, cats are believed to be the only mammals that don't taste sweetness! To unsubscribe at any time, reply STOP to this message.
tim_hutton | 2 years ago | on: Setris – Tetris with Sand Physics
Sandy Crush
tim_hutton | 2 years ago | on: Why do ships use “port” and “starboard” instead of “left” and “right?”
The only was I can remember which is port and starboard is by thinking about boarding an airplane. The steps/tunnel are always docked on the 'port' side, just as boats always dock on the port side. The cockpit/bow is always on your left when you board.
tim_hutton | 2 years ago | on: A WWII spy who hid codes in her knitting
Not hidden in the knitting in the sense of the specific stitches (which is also very cool: https://www.popsci.com/story/diy/secret-code-messages-knitti...) but it seems she needed the knitting needle to insert the one-time codes (on a piece of silk) into a shoelace. Amazing story.
tim_hutton | 3 years ago | on: What happens when a CPU starts
One route to understanding how CPUs work is to explore the computers that have been made in cellular automata. Golly (https://golly.sourceforge.net/) has several, including one by John von Neumann, one by Edgar Codd and another by John Devore. The advantage of course is that the physics is trivial and you can see everything that happens and step backwards and forwards.
Example:
https://timhutton.github.io/2010/03/10/30984.html
https://github.com/GollyGang/ruletablerepository/wiki/CoddsD...
tim_hutton | 3 years ago | on: Ask HN: How innovative is the hydrogen industry?
I'm very skeptical of hydrogen as a general solution for reducing carbon emissions. It feels like greenwashing.
"As of 2020, the majority of hydrogen (∼95%) is produced from fossil fuels" https://en.wikipedia.org/wiki/Hydrogen_production
Producing "green hydrogen" is much more expensive: https://en.wikipedia.org/wiki/Green_hydrogen
tim_hutton | 3 years ago | on: Lisp as the Maxwell’s Equations of Software (2012)
If this is true then Haskell's type system is Noether's Theorem.
tim_hutton | 3 years ago | on: TomTom’s new mapping platform and ecosystem
This is an excellent app, it works very well. Thanks for linking.
tim_hutton | 3 years ago | on: My PhD Genealogy
> "02016"
Thank you for preparing for the Y10K problem.
tim_hutton | 3 years ago | on: TV backlight compensation (2020)
I need this for my Android phone to compensate for a burnt-in image.
tim_hutton | 3 years ago | on: Why Stephen Fry is arguing against political correctness (2018)
"the sensation they are experiencing is not being cancelled but merely going out of fashion" - https://www.theguardian.com/commentisfree/2022/aug/14/terry-...
tim_hutton | 3 years ago | on: Latest Busy Beaver champion has too many digits to count
As a Golly file, so you can run it for yourself: https://github.com/GollyGang/ruletablerepository/raw/gh-page... (4kB)
In Golly: File > Open Pattern... > open the zip itself (don't unzip first).
tim_hutton | 4 years ago | on: Journey to the Edge of Reason: The life of Kurt Gödel
Gödel's incompleteness isn't a practical obstacle to proof assistants - it will never stop us formalizing proofs and searching for new theorems. It's irrelevant to their operation and will continue to be for all time.
If Gödel's incompleteness applies to the theorem you are trying to prove then it means that the theorem has been very carefully set up with reference to the axioms that you are using in order to be unprovable. It's not something you will stumble across otherwise.
Think of it like this: imagine knowing that maths will stop working if a certain very specific enormous number appears in your calculation. This would keep mathematicians up at night with worry but it would have no practical effect on anyone else because the enormous number simply never appears.
tim_hutton | 4 years ago | on: Google is saving $1B per year as a result of employees working from home
Imagine how much nicer the cities of the world would become with many of the offices turned into residential. There would be a rebirth of local community.
tim_hutton | 5 years ago | on: Daft Punk Break Up
French 79: https://www.youtube.com/watch?v=yAv5pLO37mE
tim_hutton | 5 years ago | on: Gravity is not a force – free-fall parabolas are straight lines in spacetime
In another comment zestyping posted this video which also has spacetime contracting, in a sense: https://www.youtube.com/watch?v=wrwgIjBUYVc
tim_hutton | 5 years ago | on: Gravity is not a force – free-fall parabolas are straight lines in spacetime
This is a great question!
page 1
1. Activity in geostationary orbits.
2. Orbits where the planet's year is exactly divisible by its day, eliminating leap years.