PhET Progress Report

Sam Reid

Feb 15, 2007


An online version of this report is available here.

Here’s a pie chart representation of the time distribution.


Energy Skate Park

  • Meetings to discuss bugs & tradeoffs in design
  • Collaborated with Dubson
  • New physics (feasibility test)
    • Dynamics are in coordinate frame of spline
    • Spline arc length numerical approximations
    • Motion is constrained inherently
  • New spline implementation
  • Improved test cases
    • “Save” also stores skater’s initial conditions.
    • Test cases load quickly
    • Easier to create and use test cases.
  • Added 4 test cases.


Build Process

  • Collaborated with De Goes
  • Discussed build, deployment, proguard, jnlp, etc.



  • Discussion with Malley & De Goes about version control
  • Creation of Subversion repository on Sourceforge
    • Hooks, etc.
  • Tested new Subversion repository


Molecular Reactions

  • Collaborated with De Goes
  • Stopwatch w/ Piccolo, Swing, phetcommon


Upcoming Work (in order of proposed activity)

  1. Energy Skate Park

a.       Collaborate with Dubson to improve physical model

b.      Track should bump up when beneath ground

c.       Evaluate new physical model before working on any physics-related bugs.

  1. Collaborate with De Goes/Malley to convert source code repository to Subversion
  2. Rotational Motion Simulation I

a.       Time series/playback

b.      Lots of minor user interface updates

c.       Performance enhancement

  1. Rotational Motion Simulation II
  2. CCK…



  • Kathy and/or Wendy please prioritize: big list of todo’s
  • Continue spline physics reimplementation with Dubson?
    1. Discussion of cost/benefit?
  • Collaborate with De Goes on Rotational Motion/Torque?