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

Cute Toddler Story

Those of you who follow me on Twitter/ Facebook have been getting the occasional snippet of cute dialogue from SteelyKid over there. This one’s a little too long for breaking into 140-character blocks, so while I wait for her to come downstairs so we can make pancakes, a cute SteelyKid story: We play a surprising… Continue reading Cute Toddler Story

Happy Saturday Music

SteelyKid’s third birthday is next week, but we’re going to Kate’s mother’s for the day itself, so we’re having a birthday party today for her and her friends from day care. So, even though all the news is depressing, it’s a day to be happy. So here’s a happy song: (OK, I don’t quite know… Continue reading Happy Saturday Music

Friday Physics Videos

We’re having a birthday party for SteelyKid tomorrow, so I have a ton of stuff to do today. I may have something more substantive later, but for the moment, here are a couple of videos to enjoy. First, from the Minute Physics set of videos at YouTube, an explanation of why you have quantum physics… Continue reading Friday Physics Videos

How Good Are Polarized Sunglasses?

A while back, I explained how polarized sunglasses work, the short version of which is that light reflected off the ground in front of you tends to be polarized, and by blocking that light, they reduce the effects of glare. This is why fishermen wear polarized sunglasses (they make it easier to see through the… Continue reading How Good Are Polarized Sunglasses?

Playground Physics: Roller Slide Mystery

We took SteelyKid to the playground at one of the local elementary schools on Sunday morning. this one includes an odd sort of slide, made of dozens of rollers that are 1-2 inches in diameter (they’re all the same size– the range is just because I didn’t measure them carefully). They’re on really good bearings,… Continue reading Playground Physics: Roller Slide Mystery