Thursday Eratosthenes Blogging: Measuring Latitude and Longitude with a Sundial

As I keep saying in various posts, I’m teaching a class on timekeeping this term, which has included discussion of really primitive timekeeping devices like sundials, as well as a discussion of the importance of timekeeping for navigation. To give students an idea of how this works, I arranged an experimental demonstration, coordinated with Rhett… Continue reading Thursday Eratosthenes Blogging: Measuring Latitude and Longitude with a Sundial

The Test(ing) of Time: The Surprisingly Good Hourglass

My class this term is a “Scholars Research Seminar” with the title “A Brief History of Timekeeping,” looking at the science and technology of timekeeping from prehistory through modern atomic clocks. This is nominally an introduction to “research methods,” though the class operates under a lot of constraints that fully justify the scare quotes, at… Continue reading The Test(ing) of Time: The Surprisingly Good Hourglass

Christmas Physics: How Strong Is One Grinch?

And what happened then? Well, in Who-ville they say That the Grinch’s small heart Grew three sizes that day. And then the true meaning Of Christmas came through And the Grinch found the strength Of ten Grinches, plus two — Dr. Seuss’s How the Grinch Stole Christmas It’s nearly Christmas, so SteelyKid keeps demanding to… Continue reading Christmas Physics: How Strong Is One Grinch?

Sad Balloon Physics II: How Long Will a Balloon Last?

As a follow up to Wednesday’s sad balloon post, the repair that lofted it back to the ceiling was a temporary reprieve, unsurprisingly. After 24 hours, more or less, it had sunk back down to the point where the ribbon was just barely touching the floor. On the one hand, it looks kind of pathetic… Continue reading Sad Balloon Physics II: How Long Will a Balloon Last?

The Physics of a Sad Balloon

My birthday was two months ago, and SteelyKid’s was the weekend before last, so we’ve had balloons running around the house for a good while now. Meaning that when I came into the library yesterday, I saw the sad little image on the right: a half-deflated Mylar balloon floating at about chest height. Now, the… Continue reading The Physics of a Sad Balloon