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Dr. Shapiro's Puzzle of the Day

Today's Puzzle

Friday, September 11
If you're in the Bay Area, you probably experienced eerie dark skies this week, particularly on Wednesday.* I tried to capture that weird atmosphere on a digital camera, but I didn't know enough about photography to do it well. One of the shots at left is bright and blurry due to an overly long exposure; the other shows the orange tint of the sky but the contrast is exaggerated by the flash. You can't trust the colors!

Nevertheless, if you know that these photos were taken in the late afternoon, they give one piece of incontrovertible evidence that Wednesday's skies were abnormally dim. How so?**

* If the smoke and darkness has been getting to you, know that you're not alone. I don't have a lot of self-care tips but baking an easy apple cake never hurts.
** The answer is not "Raccoons only come out in the dark", which while generally true does not apply to garden statuary.

   


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Yesterday's Puzzle + Solution

"All trades, their gear and tackle and trim": the counter I'm holding in the photograph at left was a prized possession of my childhood, given to me by my father for the purpose of counting something on trips with him to Sacramento, Suisun, and the Sierra Nevada. For him, the counting was (and is) a professional activity; I did it for the love of numbers. What were we counting?

Hint Other equipment carried by my father on these trips included a net and a tin of small envelopes; and I occasionally made use of pins and spreading boards when we got home.

Solution We were counting butterflies; my dad is a lepidopterist. (Here's his website.)

Congratulations to yesterday's solvers Maddy, Inca, Yana, Mr. Gregg, and Kate. Thanks to everybody who made a guess. (Fish and birds were popular guesses. My favorite guesses were "steps" and "cards".)

About This Site

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.