Gerry Ruch: automated urban astronomy

Gerry told us about the University of St. Thomas’ efforts to build and use a fully automated 17″ astronomical telescope. He described how they dealt with vibrations (it’s mounted on the top of a parking garage), alignment, automation, outreach, and pedagogy. The ultimate goal is to let students from anywhere make a job and then analyze the data.

Here’s the recording.

We’re off for the next few weeks. Our calendar (found on our blog) should be up to date.

Eugenia Etkina: ISLE-based teaching and new textbook

We talked Eugenia Etkina about the Investigative Science Learning Environment (ISLE) and the new textbook she has spent more than a decade developing to support ISLE teaching. 
Link to Physics text:

Here’s the recording link.

This week (4/2 9:30 pm ET) we’ll be talking with Gerry Ruch about his work installing a share-able telescope in an urban environment.

Physics Student Journal Club #1

We talked with Jim Reardon about his work on optimizing running 400m and 800m track races. We talked about various physical models and talked about how we can use relatively simple models to investigate complex phenomena. Jim is happy to continue to interact with any students with questions, simply send questions to Andy Rundquist (firstname.lastname@gmail).

Here’s the recording.

This week (3/26) we’ll be hosting Eugenia Etkina to talk about her new calculus based physics text. Join us!

Physics Student Journal Club prep

This Wednesday (3/19/2014) we’ll be joined by Jim Reardon to talk about his paper about the optimal way to run 400 and 800 meter races. Here are some questions you can use to get your students thinking about this:

  • Should you always run your hardest?
  • Should you try to go the same speed the whole time?
  • Should you be exhausted by the end?
  • For how long should you accelerate?
  • Jim says that entropy is the key, what does that mean to you?

Here are some ideas about the three models propose:

  1. You provide propulsion, friction slows you down, let’s keep track of the energy.
    1. \frac{dv}{dt}+\frac{v}{\tau}=f(t)
      1. v is velocity
      2. \tau is the friction coefficient
      3. f is the propulsive force (per unit mass)
    2. \frac{dE}{dt}=\sigma-fv
      1. E is the runner’s energy supply
      2. \sigma is the replenishment rate
    3. you get all the values by fitting to the races we have data for
    4. predicts that you should run your second half of the race faster
  2. Energy comes both aerobically and anaerobically
    1. aerobic is constant
    2. anaerobic decays
    3. max power is used
    4. energy goes into kinetic energy, drag losses, and heat
    5. \lambda S_0e^{-\lambda t}+R=A v+\frac{1}{2}\rho v^3 S C_D+m v \frac{dv}{dt}
      1. S is the effective area
      2. rho is the air density
      3. the rest are fit parameters
    6. predicts deceleration in the 100m race
    7. still gets 400 and 800 meter elite races wrong
  3. X factor
    1. entropy is key!
    2. calculus of variations
      1. maximize distance in given time
      2. similar to Brachistochrone approach
    3. matches data very well!

Physics Student Journal Club

Unfortunately the web conferencing software we use is suffering an outage tonight (3/12) so we’re postponing this discussion until next week (3/19).

Upcoming weeks:

  • 3/19 Rescheduled Physics Student Journal Club
  • 3/26 Eugenia Etkina talking about her new general physics textbook
  • 4/2 Gerry Ruch: Urban telescope at University of St. Thomas in St. Paul MN

Tom Jordan: QuarkNet

Tom told us about the history and future of QuarkNet. We talked about the value to both the researchers and the teachers involved. It was interesting to hear about their efforts to build a community of physics educators.

Here’s the recording.

This week (Wednesday 3/12 at 9:30pm ET) we’ll be doing our first physics student journal club. The paper we’ve chosen is entitled “Optimal pacing for running 400m and 800m track races” by Jim Reardon (who will be joining us). If you’re interested, encourage your students to join us, or have them send along any questions to Andy Rundquist (

Eric Mazur: New general physics textbook

Eric talked with us about the format, design, implementation, and philosophy issues he and his collaborators dealt with when writing the new book. He talked about how conservation theorems are front and center in the book and he shared new approaches to teaching collisions and energy.

Here’s the recording.

There is no meeting this week. Join us next week (3/26) when we host Tom Jordan to talk about QuarkNet.

New initiatives: physics student journal club and student simulations

Physics Student Journal Club
Last week we met to brainstorm what a Physics Student Journal Club might look like. We decided that we’d give this a try:

  • Pick an article
    • Accessible (both logistically and content-wise)
    • By someone we might cajole into joining our conversations
    • Has conclusions that can be critically analyzed (so not just a report about some new cool thing)
  • Have teachers commit to having their students read it and contribute to a wiki of sorts to see how others are struggling/thinking about the article.
  • Commit a Global Physics Department night to a general conversation about the paper

So here’s the plan. We’ve selected a paper entitled “Optimal pacing for running 400m and 800m track races” by James Reardon (that’s the ArXiv link so it’s accessible to everyone), who we will reach out to. We’ll schedule March 12 for our first try of a meeting.

Physics Student Simulations
We’re going to start a new category on our blog site ( to collect student simulations. They’ll provide both artifacts (movies, plots, etc) and a description. For this month the prompt is: True or False: electrons released from rest always follow trajectories that follow electric field lines.

Submissions should be emailed to Andy Rundquist (first name dot last name at gmail).

Here’s the recording of our meeting.

Join us this week as we host Eric Mazur to talk about his new introductory physics text that is centered around conservation theorems.

Georg Rieger: 2 stage exams

Georg shared with us his experiences using two-stage exams. We talked about the impact to classroom climate, student learning, and instructor planning. Here’s a link to a recent article about it.

Here’s the recording.

Join us this week (1/29 at 9:30 pm ET) as we talk to people from Note that’s a change from the original plan to brainstorm a student physics journal club, which we’ll do the next week.