Today's Puzzle
Friday, November 20
This is the last new puzzle until school resumes. Craving more puzzles? Check out the updated archive. Have a good Thanksgiving Break!
MacGyver is a TV character known for finding elegant solutions to problems using whatever items happen to be lying around. Let's see if you can be a mathematical MacGyver. Here is a very pleasant curve which you might know as a sine wave:
You have string, tacks, a compass and straightedge, a candle, a flashlight, a bicycle, a sharp knife, a camera, a roll of paper towels, a party hat, a pencil, paint, wire, lipstick, a live bobcat, and 5 pounds of potato salad. How can you draw a mathematically accurate sine wave?
You are not required to use all the items, but Dr. Shapiro will give creativity points and unrestrained admiration to those who somehow do.
Yesterday's Puzzle + Solution
The other day, my 15-month-old daughter Mira made a joke: she deposited a segment of an orange in her empty water cup, pretended to "drink" it, then looked at me and laughed. Then she took the orange segment out of the cup, put it back in, and repeated the performance.
In honor of Mira's first (?) joke, here's a puzzle about a joke. What punchline has been blurred out in the classic comic strip at left?
BONUS, to keep things interesting for those who know their Calvin and Hobbes cold: What else could Calvin's drawing represent?
Solution
Alternative answers included a white cat in a snowstorm, Hobbes covered in flour, a carpet tack, a mushroom, and a very tiny and very lonely mushroom under a microscope.
Congratulations to yesterday's solvers Ena, Jackson, Lemonade (and Allie), Leo S., Peter M., Charlie, Aditi, and Kate. Thanks to everybody who made a guess!
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 November 2020.