You can make a wooden basin or waterproof pit. Fill it with water, drop in hot stones from a fire. This is common in preceramic cultures. https://en.wikipedia.org/wiki/Pot_boiler -- https://en.wikipedia.org/wiki/Stone_boiling

"ɢʀᴇᴇᴛɪɴɢs ғᴇʟʟᴏᴡ ғʙɪ ᴀɢᴇɴᴛ"

"If once a man indulges himself in murder, very soon he comes to think little of robbing; and from robbing he comes next to drinking and Sabbath-breaking, and from that to incivility and procrastination. Once begun upon this downward path, you never know where you are to stop. Many a man has dated his ruin from some murder or other that perhaps he thought little of at the time." -- Thomas De Quincey

There are ultra thin credit card size BT / GPS trackers designed for wallets. https://duckduckgo.com/?q=credit+card+size+gps+tracker&ia=we...

Cool!

Area code 272 (CSC for 'Cancer Support Community') 1-272-867-5309

There's a star trek fan who has a primary dog and an emergency backup dog. There's also the british 'heir and a spare'.

There's a 'build the Japanese train system' board game "1889" -- https://boardgamegeek.com/boardgame/23540/shikoku-1889 -- https://www.amazon.com/Shikoku-1889-Railways-Players-Minute/...

Obligatory xkcd. Mouseover for The Last Answer. https://www.explainxkcd.com/wiki/index.php/1448:_Question

A perfect hash function https://en.wikipedia.org/wiki/Perfect_hash_function has to be specially constructed for each desired set of inputs. Generic hash functions cannot be 'perfect'.

Original paper: https://www.science.org/doi/10.1126/sciadv.aec2916