PhET Progress Report

Sam Reid

June 21, 2007

An online version of this report is available here.

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

PhET Dependencies

· Organized dependencies in PhET’s Java simulations for which we do not hold copyright, for purposes of licensing/legal issues.

· Wrote software to assist in classification and visualization of media usages.

a) Images

b) Audio

c) Software

· A similar thing should be done for Flash simulations.

· Didn’t include build subproject dependencies yet, since it’s not clear we would want to relicense them.

· Should have a discussion about several items:

1. Some images may not have a compatible license (or a known license). We should discuss the tradeoff of substituting a compatible image or drawing our own.

2. One dependency used in Bound States and Quantum Tunneling is GPL only; I have contacted the authors, and am waiting for a reply. It would take us roughly 15-25 hours to rewrite this code ourselves.

3. Our build system has a known dependency on Proguard, a GPL only product. We could remove this dependency with (probably) less than 5 hours of work.

Rotation

· Cleanup of charting code

· Initial support for aligning time series (for numerically estimated derivatives)

· Documentation

· Testing

Associated Legendre Polynomials

· Identified license for associated legendre polynomials used in Hydrogen Atom.

· Rewrote & Tested algorithm, compatible with previous results up to L=5 only (discrepancy not known why), sufficient for Hydrogen Atom sim.

Piccolo PSwing drag bug

· Identified & resolved this problem (with John)

o More difficult than we expected (not just a sign error)

Source Distribution

· Posted a downloadable source distribution of PhET’s Java simulations on our SourceForge host site:

http://sourceforge.net/projects/phet/

We should advertise this somehow.

Moving Man

· Removed dependency on Java Expression Parser (GPL + $)

· Switched to another evaluation engine “beanshell” (LGPL)

o Not all functions are directly supported yet, currently supports Java expressions and shortcuts for cos, sin, pi, log, pow. Easy to add more, if we like

Nuclear Physics

· Main site version was broken in Java 1.6; replaced with working copy.

Upcoming Work

· Rotation/Torque (with John)

1. Time Series

2. Physical model (with correct offsets in derivatives)

3. Charts (with correct layering for data series?)

· Interview with Beth Lindsey

· Licensing issues/Meet with Kate Tallman?

· GUI for translation system

· CCK

1. remove old CCK, upgrade to CCK DC Only version after some small fixes