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Unbounded Recursion

wiki.secretgeek.net

They mentioned the Droste effect, but not the fact that by Brouwer fixed-point theorem[0], there is a fixed-point, a point that every image contains.

Similar with mirrors, or cameras that capture their own images (although there is a delay (there is a delay with mirrors too)), or in the cases of maps. Did you know that if there is a map of an area in the depicted area, then there is a fixed point, which is in the case of maps a 'You are Here' point, that is, it is above its location?

[0] : https://en.wikipedia.org/wiki/Brouwer_fixed-point_theorem#Il...

It would be pretty alarming if I could hold a map of the state I’m in and not see my own location anywhere on it!

Conversely, it would pretty alarming if you could see yourself in that location on the map.

Not so alarming if the map comes equipped with a suitable adjoint (best approximation to inverse) map with which it may be composed; it's by pulling back that "taste classifies, and it classifies those who classify."

Maps of Chicago typically don't have a way to include lower Wacker, and plenty of people haven't even heard of lower lower Wacker.

Even Google Maps struggles with this, bouncing between upper and lower on street view, and pickups with Uber and Lyft are iffy on that street (at least back when I first installed them, gave up on it after a while).

The most unbounded recursive time travel paradox story has to be All You Zombies by Robert A. Heinlein. You can find it at https://gist.github.com/defunkt/759182/ad44c6135d168ae54503a....

An extended and elaborate demonstration of the "if you have to explain the joke" principle.

What do you mean? What joke is explained? Explained how? Can you please explain?

It's discussed in more detail here: https://news.ycombinator.com/item?id=39799743

After so many years, this title made me really catch the name "Unbound" for the recursive DNS resolver...

I also enjoyed the last "Next Steps" reference at the end of "Functional Programming in Lean":

- Functional Programming in Lean may be interesting to readers who enjoy jokes about recursion.

If I really wanted to look up the discussion of recursion or infinite loops in a book index, I would be rather annoyed if a cute joke would cause the actual reference to be absent.

In my 1990 copy of Steele's Common Lisp The Language (2nd edition), the index definitions of iteration and recursion cross reference each other, but do point at the actual definitions as well.

However, the joke that he does use in the index is that the entries for the Teenage Mutant Ninja Turtles (who are used an example of a list somewhere) also includes the dates of the renaissance artists (Michelangelo, etc) they were named after.

I'm not sure which is the more worrying: that I noticed this in the first place, found it really funny, or that I remembered it 30 years later.

https://books.google.ch/books?id=V3ByEAAAQBAJ&pg=PA590&lpg=P...

    Oxford
      professorial appointments, 505
      stories, 481
      breakaway technical college somewhere
        in the fens (see Cambridge)

elsewhere on that page are many other means by which we may guess Prof. Körner's aesthetic theory of indices.

[0] Canonical proof that HN comments are Recursive Complete [0]

> This is funny because "recursion" and "condescension" are two words that rhyme...

"lol"? :(

'Aversion' also rhymes with 'recursion, as does 'version', 'Persian, 'subversion', 'introversion' and 'King James Version' amongst others

https://en.m.wiktionary.org/wiki/Rhymes:English/%C9%9C%CB%90...

Very thoughtful

Em, is that you?

Sure. "Condescension", however, definitely does not, afaik for any accent; except... maybe that's the joke? ;P

I was just about comment that I'm a little afraid to start reading the article at this time of night. Apparently the comments aren't safe either! ;)

Disappointed that scrolling to the bottom did not lead to the content at the top of the page.

Yes. I was expecting a Möbius strip page too.

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