Physics Educational Software

Written by Daniel V. Schroeder and others.

All of this software is available free, as is. Read on to learn more...

New: JavaScript/HTML5 Demonstrations

These have only minimal interactivity, but they demonstrate the feasibility of using the new standard web technology for computationally intensive physics simulations with animated graphics. They even run (slowly) on mobile devices!

• Ising model
• Molecular dynamics
• Fluid dynamics

Here's a blog article summarizing my benchmark results with these three demos, and explaining why I've decided to switch from Java to JavaScript/HTML5 for web-delivered physics simulations.

Java Applets

Run these quick, before Java support in web browsers disappears completely!

• Radiation Applet by Andrew Flinders (WSU student): draws and animates field lines of an accelerated charge.

• Molecular Dynamics Applet: simulates molecular motions in two dimensions.

• EField Applet: draws electric fields for any two-dimensional arrangement of charges.

• Sky Motion Applet: a planetarium simulation designed especially to show heavenly motions.

• Zoomer Applet: a modest attempt to show earth's place in the universe.

Older Thermal Physics software for Mac and Windows

• Molecules is a two-dimensional molecular dynamics simulation, similar to the Molecular Dynamics applet listed above. This version has somewhat different features including the ability to simulate two types of dissimilar particles. The program is available for several platforms:
  • Mac OS 8-9. Also runs in the Classic environment under OS X. Click here to download (.sit format, 792k).
  • Mac OS X. Also runs under OS 9 with CarbonLib. Note that, due to the double-buffered graphics on OS X, the Classic version (above) gives better performance and smoother animation (though with some flicker). Click here to download (.sit format, 975k).
  • Windows 95 or better. Click here to download (.zip format, 536k).
  • REALbasic project source file. If you have REALbasic, just click here to download the project file (.sit format, 143k).
  • Source code in plain text format (61k; possibly useful if you want to see the algorithms or port the program).
  • This software is issued under the GNU General Public License, which you should read if you intend to modify or distribute the program.

• Ising is a Monte Carlo simulation of the two-dimensional Ising model, demonstrating phase transitions of a magnetic system. You can adjust the temperature, magnetic field, and lattice size (up to 400x400) while the simulation is running. Besides graphical output, the program keeps track of the current value, average, and standard deviation of the energy and magnetization, which you can copy and paste into a spreadsheet for further analysis. The current version of Ising is 1.1, posted 22 September 2002 (see source code for a list of changes since version 1.0). This program is available for several platforms:
  • Mac OS 8-9. Also runs in the Classic environment under OS X. Click here to download (.sit format, 728k).
  • Mac OS X. Also runs under OS 9 with CarbonLib. Note that, due to the double-buffered graphics on OS X, the Classic version (above) gives slightly better performance and smoother animation in the "update continuously" mode. Click here to download (.sit format, 910k).
  • Windows 95 or better. Click here to download (.zip format, 473k).
  • REALbasic project source file. If you have REALbasic, just click here to download the project file (.sit format, 89k).
  • Source code in plain text format (32k; possibly useful if you want to see the algorithms or port the program).
  • This software is issued under the GNU General Public License, which you should read if you intend to modify or distribute the program.
  • There's also a stripped-down Java version of this program: click here to view or download the source code.
  • To see a bare-bones version of this program for True BASIC, click here.

Really Old Mac Software

The programs described below were developed for the Macintosh computer circa 1985-92. They are small, fast, and easy to use, but lack the color graphics that everyone expects these days. As far as I know, all of them run fine on PowerPC-based Macintosh systems, including OS X systems under the Classic environment. It might be possible to run them on Intel-based systems using third-party emulation software, but I've never tried this. Except for the Radiation and EField Applets (see above), I have no versions of these programs for Windows or other operating systems. However, the Spins program has been ported to Java by a group at Oregon State University. Click here for more information about this Java version of Spins.

All of the programs described below, except for the Radiation program, were written by Dan Schroeder and Michael Martin. To download an archive of all of these programs, click here (.hqx format, 213k). The Radiation program is in a separate archive (see below).

• E-Field shows the electric field (represented by arrows) of an arbitrary two-dimensional distribution of point charges or of infinite-line charges (running perpendicular to the screen). It has a very easy user interface and is suitable for high school or college introductory courses. (Unless you're on a pre-OSX Mac, use the EField applet instead of this program.)

• B-Field is similar to E-Field but shows the magnetic field of an arbitrary arrangement of infinite wires running perpendicular to the screen.

• Radiation draws and animates the electric field lines around an accelerated point charge undergoing various motions, as described here. This program was created by Blas Cabrera, Sha Xin Wei, and Jim Terman; it is now in the public domain. Click here to download this program (.hqx format, 40k). (Unless you're on a pre-OSX Mac, use the new Radiation Applet instead of this old program.)

• Q-Wave is similar to Fourier, but can analyze a wavefunction using any of three different sets of basis functions, corresponding to box, harmonic oscillator, and linear potential energy functions.

• Schrodinger animates the time dependence of a one-dimensional wavefunction built as a linear superposition of the first six basis functions for either the box or harmonic oscillator potential.

  

• Quantum1D is a bare-bones animation (with no user interface) of one-dimensional scattering of a wavepacket from a step potential. A few parameters can be specified by the user upon startup.

• Spins allows the user to link together Stern-Gerlach devices to explore the mysteries of quantum mechanics for a system that is mathematically very simple. This program is described in an article in American Journal of Physics 61, 798-805 (1993). New: a Java version of this program is now available from Oregon State University.

Last modified on March 2, 2013.