tim_hutton

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.

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.

"According to biographer Robert Wright, the character Stephen Falken in the film WarGames was modeled after Fredkin." [https://en.wikipedia.org/wiki/Edward_Fredkin]

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.

Sandy Crush

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.

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.

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...

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

If this is true then Haskell's type system is Noether's Theorem.

This is an excellent app, it works very well. Thanks for linking.

> "02016"

Thank you for preparing for the Y10K problem.

I need this for my Android phone to compensate for a burnt-in image.

"the sensation they are experiencing is not being cancelled but merely going out of fashion" - https://www.theguardian.com/commentisfree/2022/aug/14/terry-...

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).

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.

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.

French 79: https://www.youtube.com/watch?v=yAv5pLO37mE

In another comment zestyping posted this video which also has spacetime contracting, in a sense: https://www.youtube.com/watch?v=wrwgIjBUYVc

This is a great question!

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.

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.

e.g. Dual Photography: https://graphics.stanford.edu/papers/dual_photography/

Or camera feeds on the road that the car can access, to allow the driver to see around corners ahead of them.

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.

A strange game. The only winning move is not to play.

It's just a cloud of dust? From the thing that the elephant picked up off the dusty ground?

Yes, you are quite right. My question was poorly worded.