"Kidney bean–shaped", "cardioid", "colored according to", "sea horse valley", and "assumed to have escaped" are phrases from the MathWorld encyclopedia article on what subject?
Hint
Here are a few more phrases from that page: "computer-generated", "defined by iterating", and "increasingly convoluted". No mention is made of biscotti.
California's state route emblem is a unique shape (as seen at left). What is that shape supposed to represent?
(It's not a beehive... that would be Utah.)
Hint
California State Route 49 passes through Madera, Mariposa, Tuolumne, Calaveras, Amador, El Dorado, Placer, Nevada, Yuba, Sierra, and Plumas counties.
I trust that's the kind of quality information you were looking for when you clicked "Hint". Happy to help!!!!
Solution
The sign shape represents a gold prospector's shovel. Route 49 was a subliminal hint to make you think of the 49ers (the miners who came to California in the Gold Rush of 1849). Not coincidentally, CA 49 runs through the gold country.
I stole the idea for this puzzle from a wonderful map of state highway emblems (source):
Cue the arguments over Maryland vs. Iowa and Missouri!
While many states have symbols or other decorations on their signs, California seems to be the only one that doesn't stick them on an easy-to-cut rectangular background.
There were lots of interesting guesses yesterday: a mountain, Half Dome or El Capitán in particular, a hut, an acorn, a "stubby cactus", a Reuleaux triangle or a poorly drawn Wankel engine, and (my favorite) an upside-down persimmon. This is for you, Graham:
Congratulations to yesterday's solvers Anna K., Inca, Leo S., Maddy, Barbara, Mr. and Mrs. Gregg, and Dr. Shapiro. Thanks to everybody who made a guess!
Though he now teaches mathematics, Dr. (né Mr.) Shapiro's first job in a K–12 school was as a lunch monitor in Davis, CA. It was there that he originated the Puzzle of the Day, even rewarding correct answers with tickets in denominations like "15 points" (though without a clear idea of how he'd ultimately redeem these). Dr. Shapiro's favorite puzzle from this pre-professional era was "Tell me the location of the beehive on this campus."
Ten years later, Dr. Shapiro revived Puzzle of the Day at Proof School, writing each day's puzzle on a name tag. After 600 puzzles or so, he was just starting to feel normal about students reading his chest all the time when campus closed and the puzzle, like the rest of our lives, moved online. New puzzles are posted daily on school days.
Want to catch up on old PotDs? There's an archive currently containing puzzles from March to June 2020.
