How Fast Should I Drive?

Normalized cost vs. speed for a car getting 20mpg.

We spent this past weekend in Florida, visiting Kate’s mom and her husband, who moved down there in October. This was a huge hit with the kids, who were very excited to fly on an airplane (four of them, actually, as we changed planes in Baltimore both ways). They also got a big kick out… Continue reading How Fast Should I Drive?

SteelyKid: Junior Rock Star Scientist

SteelyKid playing with the rocks at the Schenectady Curling Club's open house.

I’m off to The City for TED@NYC on Tuesday, and while I might schedule something with the approximate text of my talk for Wednesday morning, more substantial blogging won’t resume until Thursday. But I don’t want to leave political post as the top thing on the blog, so here, have a cute kid picture. This… Continue reading SteelyKid: Junior Rock Star Scientist

How Deep Does Veritasium’s Bullet Go?

Screen shot from the video of the block being shot into the air.

After a couple of very productive days where I closed my Twitter tab because it was too freakin’ annoying to read, I checked in briefly Wednesday morning, and found Rhett Allain and Frank Noschese discussing this Veritasium bullet-in-block experiment: Tom at Swans On Tea offers some analysis, and Rhett offers a video response doing out… Continue reading How Deep Does Veritasium’s Bullet Go?

Physics of the Bouncy-Bounce

With SteelyKid inside the bouncy-bounce at SteelyPalooza.

SteelyPalooza came off very well, despite high disaster potential. We were, after all, inviting a dozen five-year-olds plus assorted siblings to our house, on a day when Kate and The Pip were out of commission due to coxsackie virus. Everything went smoothly, though: the kids loved the bouncy-bounce, SteelyKid’s playset and playhouse, and the six-person… Continue reading Physics of the Bouncy-Bounce

Driving a Simulated Pendulum

A simulated pendulum driven near resonance.

Some time back, I spent a bunch of time writing a VPython program that simulated the motion of a pendulum, which turned out to do some strange things. In the comments to that, there were two things worth mentioning: first and foremost, Arnoques at #5 spotted a small error in the code that fixes the… Continue reading Driving a Simulated Pendulum

Reflecting, Totally; or Why the Pool Looks Shiny from Underwater

Total internal reflection of a laser off a water surface.

The other day, I made a suggestion to one of my research students of an experiment to try. When I checked back a day later, she told me it hadn’t worked, and I immediately realized that what I had told her to do was very stupid. As penance, then, I’ll explain the underlying physics, which… Continue reading Reflecting, Totally; or Why the Pool Looks Shiny from Underwater

Baseball Is Pretty Random

Batting averages compared to career totals for six famous players.

After Thursday’s post about sports and statistics, a friend from my Williams days, Dave Ryan, raised an objection on Facebook: There’s an unstated assumption (I think) in your analysis: that there is some intrinsic and UNALTERABLE statistical probability of getting a hit inherent in every hitter. If that is the case, then yes — a… Continue reading Baseball Is Pretty Random

Mysteries of the Simulated Pendulum

Pendulum with a spring constant of 25 N/m, unstretched (left) or pre-stretched (right).

Last week, I spent a bunch of time using VPython to simulate a simple pendulum, which was a fun way to fritter away several hours (yes, I’m a great big nerd), and led to some fun physics. I had a little more time to kill, so I did one of the things I mentioned as… Continue reading Mysteries of the Simulated Pendulum

Simulating a Pendulum

Screen shot of VPython simulation of a pendulum

There’s a famous story about Richard Feynman at Cornell suffering from the science equivalent of writer’s block, after WWII. He was depressed and feeling like everything he did was pointless, until one day he spotted a student throwing a plate up in the air in the cafeteria. As the plate spun, it wobbled, and the… Continue reading Simulating a Pendulum