The Tricky Thing About Simulated Dynamics

The minimum separation as a function of the release position in the toy model of the charged tape system.

In the previous post about simulating the attraction between sticky tapes using VPython, I ended with a teaser mentioning that there was a discrepancy between the simulation and the theoretical solution from directly solving the equations. The problem is kind of subtle, but clearly visible in this graph from that post: In this, we see… Continue reading The Tricky Thing About Simulated Dynamics

Physics Hangout in Need of Better Title

What with the umpteen zillion articles declaring the Death of the Blog, I’ve been toying with the idea of doing something podcast-ish for a while. Rhett Allain from Dot Physics was game, too, and suggested using Google+ to do a video hangout, so here we are talking about our classes this term: The video quality… Continue reading Physics Hangout in Need of Better Title

Simulated Tape and Universal Behavior

Comparison of the two different simulations, scaled to the "tipping point" showing the universal behavior.

Having spent a lot of time solving equations related to sticky tape models, including trying to work solutions in my head while driving to Grandma and Grandpa’s with the kids, and making some measurements of real tapes, there was only one thing left to do: try simulating this problem in VPython. Because I’m a physics… Continue reading Simulated Tape and Universal Behavior

Atomic Physics with Sticky Tape

Two pieces of sticky tape with the same sign of charge, hung from an incredibly sophisticated measuring apparatus.

In addition to making a toy model to show the tipping-point behavior of charged pieces of sticky tape, I spent some time on Tuesday trying to do something quantitative with this. Of course, Tuesday is the one day of the week that I don’t teach, and I didn’t want to go to campus to do… Continue reading Atomic Physics with Sticky Tape

Charged Tape, Toy Models, and Dimensionless Parameters

The toy model of the charged-particle detection discussed in the text. Two charges start out a distance L apart, one of them is attached to a spring with spring constant k.

One of the labs we do in the introductory E&M class I’m teaching this term involves investigating charged particles with sticky tape. If you haven’t seen it before, “invisible” tape picks up an electric charge when it’s peeled off a surface quickly, and with a little care, you can create both positively and negatively charged… Continue reading Charged Tape, Toy Models, and Dimensionless Parameters

Niskayuna by Fermi

The other morning, I was lying in bed and for some reason, found myself wondering what the population of Niskayuna is. While this is easily Google-able, as I said, I was in bed, and didn’t want to get up to get a device with Internet connectivity. So I tried to Fermi-problem my way to an… Continue reading Niskayuna by Fermi

Overwrought Arguments About TED Are an Existential Threat to Our Civilization

Me speaking at TED@NYC. Photo by Ryan Lash.

When I wrote about Benjamin Bratton’s anti-TED rant I only talked about the comment about the low success rate of TED suggestions. That was, admittedly, a small piece of his article, but the rest of it was so ludicrously overheated that I couldn’t really take it seriously. It continues to get attention, though, both in… Continue reading Overwrought Arguments About TED Are an Existential Threat to Our Civilization

Miscellaneous Liberal Education Stuff

The posts on box-checking and liberal arts teaching generated a fair number of comments that I haven’t really had time to address individually, across a few different social media platforms. So I’m going to collect some of the more important stuff here, in one catch-up post. –A few people, mostly in places that aren’t conducive… Continue reading Miscellaneous Liberal Education Stuff

Physics of Snow Photo Contest

Snow hanging off the edge of SteelyKid's playset.

A couple of weeks ago, I got a cool picture of snow hanging off SteelyKid’s playset, and posted a call for people to suggest physics-y ideas about that. I only got one response, probably because nobody really read the Internet over the holidays. Anyway, the next time I’m likely to have the free time to… Continue reading Physics of Snow Photo Contest