Möbius-Strip Crosswords: The Infinite Puzzle That Flips Letters
A deep dive into the history and mathematics of crosswords on Möbius strips. The post traces the legend of Robert Guilbert's 'Pago Pago'—an alleged infinite crossword on a Möbius strip—from a 1988 New York Times article to its uncritical repetition in recent books. The author then explores the geometric constraints, showing how a true Möbius strip flips letter parity, limiting usable letters. He presents a diagonal 'ladder' technique to create a solvable Möbius crossword and challenges readers to improve upon his example.
If our 'flat creatures' are the letter-forms of the crossword entries, then when the crossword loops around on itself the letter-forms will change parity: S becomes S, and so on.
- zem
qxw [https://www.quinapalus.com/qxw.html] is a wonderful open source app that lets you make crosswords with interesting topologies, complete with grid filler support, if anyone wants to experiment with them.
- wglass
Interesting article. Note that many of the clues in the article are mis numbered.
Not sure why. Refer to the original puzzles linked for the correct clues.
- srean
A long long time ago I had a fun time making Mobius strip structure out of link list(s).
Each edge of the ribbon was a linked list, connected to each other by rungs. It looped back on itself but connected crosswise .
Then if you nuked all the rungs it was clear you still got a connected piece that you could traverse over.