Futility Closet

Oh, then you will really love and want to fuck the name of the "Wave Function Collapse" algorithm! (Maybe Chuck Tingle will write a book about it.) Also "Extreme Learning Machines", "Reservoir Computing", "Liquid State Machines", and "Crab Computing" (I shit you not)! Don't even get me started on "Moveable Feast Machines".

[Welcome to Coffee Talk, with Linda Richman. Todays topic: Wave Function Collapse is neither quantum physics, particles, waves, nor collapsing functions. Discuss amongst yourselves, while I am constrained to solve all these Sudoko puzzles. Oh, I am so verklempt!]

https://news.ycombinator.com/item?id=42749675

DonHopkins 6 months ago | parent | context | favorite | on: Generating an infinite world with the Wave Functio...

Ha ha, great comment! You're right, WFC's name just refers to quantum mechanics because it sounds cool, not because the algorithm has anything to do with physics, waves, or collapsing functions (it's more just a constraint based Sudoko solver). But I perceive it more as a playful buzzword for a useful algorithm, and not as maliciously deceptive like Deepak Chopra, who I was just commenting on recently (Quantum was cool until Deepak Chopra ruined it for everybody):

https://news.ycombinator.com/item?id=42714477

I do think it's useful combined with other techniques like procedural programming, cellular automata, Voronoi diagrams / jump flooding, noise, etc, to steer the higher and lower level structures. Check out Maxim Gumin's work on…

Anyone have recommendations for learning about mechanical linkages (books/MOOC/other)? Recently I've been intrigued by things like straight line linkages:

https://en.wikipedia.org/wiki/Peaucellier%E2%80%93Lipkin_linkage

...and the Chebyshev "paradoxical" linkage:

https://www.futilitycloset.com/2015/01/03/chebyshevs-paradoxical-mechanism/

...and of course Kempe's "universality theorem", that there is a linkage that traces any polynomial curve.

https://arxiv.org/abs/1511.09002

I recently came across "Planar Linkages Following a Prescribed Motion":

https://arxiv.org/abs/1502.05623

...which looks awesome. Especially intriguing are sentences like:

"In modern terms, the procedure proposed by Kempe is a parsing algorithm. It takes the defining polynomial of a plane curve as input and realizes arithmetic operations via certain elementary linkages. In this work, we approach the question from a different perspective... ...By encoding motions via polynomials over a noncommutative algebra, we reduce this task to a factorization problem."

But currently the terminology used is considerably over my head. Anyone know what branches of math you should study to be able to understand things like:

"...we recall that one can embed SE2 as an open subset of a real projective space. This allows us to introduce a noncommutative algebra K whose multiplication corresponds to the group operation in SE2, hence mimicking the role played by dual quaternions with respect to SE3. A polynomial…

Just realized that the "blogs" category in my Feedly has 347 entries in it, and about half of them haven't published in more than 3 months.

Here are some that are prolific and good:

https://marginalrevolution.com/

Marginal Revolution: wide-ranging and prolific blog about economics and culture.

https://evidenceanecdotal.blogspot.com

Anecdotal Evidence: well-written personal blog, mostly observations on books.

https://krebsonsecurity.com/

Krebs on Security: about information security. It's written for a popular audience, which is about the level at which I understand the subject.

https://mjtsai.com/blog/

Michael Tsai: collects quotes from other people about ongoing software-related news.

https://acquisitiontalk.com

Acquisition Talk: about weapons system acquisition, government procurement, etc. Something I wanted to follow because it's a huge sector that doesn't get a lot of attention.

https://www.futilitycloset.com/

Futility Closet: wunderkammer-style blog with historical miscellany, quotes, puzzles, etc. Also a great podcast.

https://www.tor.com/tag/jo-walton-reads/

Jo Walton's Reading List: Not strictly a blog, but it's in my RSS feeds. I like to see what she's reading lately, and sometimes I get good recommendations from her (e.g. KJ Parker).

https://www.bldgblog.com/

BLDGBLOG: about design, architecture, etc.

https://www.thisiscolossal.com/

Colossal: about art and design.

https://www.subtraction.com/

Subtraction: about design

So this probably isn't quite what you're looking for, but my favourite podcast discovery in 2019 was Off Book: The Improvised Musical Podcast.

Each week Jess McKenna, Zach Reino, and their band are joined by a special guest and together they improvised an entire hour-long musical from scratch without anything prepared ahead of time, including the music.

It's just utterly remarkable how good and clever and funny it is given it's entirely improvised and off the cuff. In my opinion it's one of the most astonishing demonstrations of human creativity I've ever seen, and it's doubly impressive when you remember they do it every single week and still never run out of ideas.

http://www.earwolf.com/show/off-book/

I would also HIGHLY recommend the Futility Closet podcast and website. The podcast is described as "forgotten stories from the pages of history" but it's so much more than that, and so is the website. Anyone who enjoys logic puzzles, mathematics, chess, history, old books, and interesting stories will love it.

https://futilitycloset.com

https://futilitycloset.com/podcast/

Here's a previous HN submission about finding Waldo in pi (spoiler: only by cheating significantly re what counts as "Waldo"): https://news.ycombinator.com/item?id=30872676

I googled around trying to figure out what year James McKee created the Trinity Hall prime. The internet is (IMO) presenting it mainly as some kind of Wonder of the Ancient World — with the date of creation conveniently filed off. The first post below claims that the year McKee left Cambridge and created the prime was 1996. It seems to have hit peak internet presence only in the 2010s, though, so I wish there were an authoritative source to confirm (or deny) the 1996 date.

https://www.bradyharanblog.com/blog/artistic-prime-numbers

https://www.futilitycloset.com/2017/09/10/trinity-hall-prime/

https://www.futilitycloset.com/2020/01/12/more-prime-images/

> Computationally it's trivial to detect illegal moves

You're strictly correct, but the rules for chess are infamously hard to implement (as anyone who's tried to write a chess program will know), leading to minor bugs in a lot of chess programs.

For example, there's this old myth about vertical castling being allowed due to ambiguity in the ruleset: https://www.futilitycloset.com/2009/12/11/outside-the-box/ (Probably not historically accurate).

If you move beyond legal positions into who wins when one side flags, the rules state that the other side should be awarded a victory if checkmate was possible with any legal sequence of moves. This is so hard to check that no chess program tries to implement it, instead using simpler rules to achieve a very similar but slightly more conservative result.