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tim_hutton

1,220 karma · joined February 20, 2012

https://github.com/timhutton https://mathstodon.xyz/@timhutton
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tim_hutton··on 'Mathematically perfect' star system being investigated for potential alien tech
Two orbital things we might look for:

1. Activity in geostationary orbits.

2. Orbits where the planet's year is exactly divisible by its day, eliminating leap years.

tim_hutton··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··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··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··on Setris – Tetris with Sand Physics
Sandy Crush
tim_hutton··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··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··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··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··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··on TomTom’s new mapping platform and ecosystem
This is an excellent app, it works very well. Thanks for linking.
tim_hutton··on My PhD Genealogy
> "02016"

Thank you for preparing for the Y10K problem.

tim_hutton··on TV backlight compensation (2020)
I need this for my Android phone to compensate for a burnt-in image.
tim_hutton··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··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··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··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··on Daft Punk Break Up
French 79: https://www.youtube.com/watch?v=yAv5pLO37mE
tim_hutton··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··on Gravity is not a force – free-fall parabolas are straight lines in spacetime
This is a great question!
tim_hutton··on Gravity is not a force – free-fall parabolas are straight lines in spacetime
An object at rest is still travelling through time. In fact it continues to travel at the same speed through spacetime when you let it go. It's just that spacetime is distorted such that the straight line takes it across space too, as seen in the inertial frame on the right.
tim_hutton··on Gravity is not a force – free-fall parabolas are straight lines in spacetime
With two space dimensions and one time dimension (2+1), an orbit in Newtonian physics is a helix. In general relativity that same helical path would be a straight line in an interestingly curved spacetime.

Likewise I guess for the 1D gravity well case, where a sine wave would become a straight line in spacetime.

tim_hutton··on Accidental Pinhole and Pinspeck Cameras (2014)
e.g. Dual Photography: https://graphics.stanford.edu/papers/dual_photography/
tim_hutton··on Cameras Could Replace Car Mirrors?
Or camera feeds on the road that the car can access, to allow the driver to see around corners ahead of them.
tim_hutton··on Monsanto Effort to Defund Cancer Researchers
Yes perfect regulation is impossible and yes it's an arms race but it's one we have to keep fighting. The alternative (less regulation) is far worse. We've tried that.
tim_hutton··on How to Brexit? – Explore the (im)possibilities of the different Brexit scenarios
A strange game. The only winning move is not to play.
tim_hutton··on Elephant 'smoking' footage baffles experts
It's just a cloud of dust? From the thing that the elephant picked up off the dusty ground?
tim_hutton··on V8 release v6.6
Yes, you are quite right. My question was poorly worded.
tim_hutton··on V8 release v6.6
I like JavaScript a lot, I've got no problem with it. But when WebAssembly can access the DOM (or replace it) it seems likely that performance-critical code will use that instead.
tim_hutton··on V8 release v6.6
Is there still a need for performant JavaScript now that we have WebAssembly?

Edit: Apologies for wording this poorly. Clearly there is a need for performant JavaScript. My question is more about how much we expect WebAssembly to take over from what JavaScript is currently used for. Thank you for all the insightful comments!

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