Author | Lightnews

Regularly (Daily Puzzles! 🧩) @regularypuzzles.bsky.social · 6h

31 Oct 2025, kitchen table: prime time in a composite year. 31 is prime, 2025 is 45 squared. Call it Boo-lean algebra.

Regularly (Daily Puzzles! 🧩) @regularypuzzles.bsky.social · 14h

Friday's Countable number is: 860
Can you get to it only using 75, 3, 1, 4, 7, and 5?

regularly.co/countable

Regularly (Daily Puzzles! 🧩) @regularypuzzles.bsky.social · 2d

Wednesday's Countable number is: 546
Can you get to it only using 100, 75, 25, 50, 8, and 7?

regularly.co/countable

Regularly (Daily Puzzles! 🧩) @regularypuzzles.bsky.social · 2d

Okay this is genuinely wild: an infinite hotel that is completely full can still take more guests. Move everyone in room n to n+1 to free room 1. Need space for infinitely many more? Send everyone to 2n and all the odd rooms open. Infinity hates intuition.

Regularly (Daily Puzzles! 🧩) @regularypuzzles.bsky.social · 4d

Currently 2am at the kitchen table. Unpopular opinion: 0.999... equals 1. Everyone thinks they’re different, but actually no number fits between them. Does that bother you?

Regularly (Daily Puzzles! 🧩) @regularypuzzles.bsky.social · 4d

Monday's Countable number is: 381
Can you get to it only using 4, 3, 10, 9, 8, and 1?

regularly.co/countable

Regularly (Daily Puzzles! 🧩) @regularypuzzles.bsky.social · 5d

Okay this is genuinely wild: with the axiom of choice, does Banach-Tarski turning one ball into two the same size by cutting into non-measurable pieces feel like acceptable maths, or like theft?

Regularly (Daily Puzzles! 🧩) @regularypuzzles.bsky.social · 7d

Gabriel’s Horn: how can a shape have finite volume but infinite surface area, so you can fill it with paint yet never have enough to cover it?

Regularly (Daily Puzzles! 🧩) @regularypuzzles.bsky.social · 7d

Friday's Countable number is: 749
Can you get to it only using 10, 9, 4, 1, 6, and 2?

regularly.co/countable

1

Regularly (Daily Puzzles! 🧩) @regularypuzzles.bsky.social · 9d

Little game: you secretly write any real number. I write mine without seeing yours. I can still make mine larger more than half the time. Sounds wrong, but it works. It needs one random idea and a bit of nerve. What am I doing?

Regularly (Daily Puzzles! 🧩) @regularypuzzles.bsky.social · 11d

Most people believe randomness should look nicely spaced, but here's the thing: true randomness clumps. If your 'random' dots never form awkward clusters, it's probably not random at all.

Regularly (Daily Puzzles! 🧩) @regularypuzzles.bsky.social · 11d

Monday's Countable number is: 244
Can you get to it only using 1, 8, 5, 7, 9, and 10?

regularly.co/countable

Regularly (Daily Puzzles! 🧩) @regularypuzzles.bsky.social · 12d

Unpopular opinion: 0.999... equals 1. Not almost. Exactly.

Regularly (Daily Puzzles! 🧩) @regularypuzzles.bsky.social · 14d

Most people believe randomness looks messy, but here's the thing: in 100 coin flips a run of 6 heads is more likely than not. Streaks are normal.

Regularly (Daily Puzzles! 🧩) @regularypuzzles.bsky.social · 14d

Friday's Countable number is: 321
Can you get to it only using 3, 7, 6, 2, 4, and 1?

regularly.co/countable

Regularly (Daily Puzzles! 🧩) @regularypuzzles.bsky.social · 16d

Unpopular opinion: 0.999... = 1. Limit your disbelief.

Regularly (Daily Puzzles! 🧩) @regularypuzzles.bsky.social · 18d

Unpopular opinion: 0.999... = 1. It’s Monday, 13 Oct 2025, and I’m sat at the kitchen table staring at the clock: 23:59 repeating. Everyone thinks it’s 'not quite' midnight, but actually it is. Does that make sense to you, or does your brain protest?

Regularly (Daily Puzzles! 🧩) @regularypuzzles.bsky.social · 18d

Monday's Countable number is: 880
Can you get to it only using 9, 1, 5, 7, 8, and 6?

regularly.co/countable

Regularly (Daily Puzzles! 🧩) @regularypuzzles.bsky.social · 19d

Gabriel's Horn is a shape with finite volume and infinite surface area. You can fill it with a thimble of paint, but you'd need endless paint to coat the outside. Calculus is rude sometimes.

Regularly (Daily Puzzles! 🧩) @regularypuzzles.bsky.social · 21d

If the barber only shaves those who do not shave themselves, is he just cutting it too fine?

Regularly (Daily Puzzles! 🧩) @regularypuzzles.bsky.social · 21d

Friday's Countable number is: 751
Can you get to it only using 50, 25, 6, 4, 10, and 5?

regularly.co/countable

Regularly (Daily Puzzles! 🧩) @regularypuzzles.bsky.social · 23d

01:27, quiet kitchen, kettle cooling. I just got 10 heads in a row. I know each flip is independent, but Bayesian me is whispering about priors and bias. I flick one more. It spins under the strip light and begins to fall and...

Regularly (Daily Puzzles! 🧩) @regularypuzzles.bsky.social · 25d

This one never stops feeling odd: if you shuffle n cards at random, how many end up back in their original places on average?

Regularly (Daily Puzzles! 🧩) @regularypuzzles.bsky.social · 25d

Monday's Countable number is: 471
Can you get to it only using 100, 25, 9, 4, 8, and 6?

regularly.co/countable

Regularly (Daily Puzzles! 🧩) @regularypuzzles.bsky.social · 26d

Okay this is genuinely wild: you can cut a perfect sphere into a few pieces and reassemble two spheres the same size. No stretching. It is a theorem. Guess which quiet assumption in set theory makes this possible, and why you can't build it in your garage?