Scientific Java simulations

Web pages are no longer limited to static material, or even prerecorded image sequences. By embedding a Java "applet" in a web page it is possible to deliver an interactive application to the user's screen. The capabilities of this environment are in a state of flux, but the medium has already reached a stage where it can be put to good use.

The applets that are included here focus on subjects that are likely to interest physicists (and others in overlapping fields); any perceived bias in this collection is personal. The links labeled [3D] point to alternative applet versions that use Java 3D (for improved imagery); in a few cases, only the 3D versions are available.

Basic physics Masses and springs Kepler problem Electric field mapping Wave tank [3D] Gyroscopic motion Quantum wave packet (1d) Quantum wave packet (2d) [3D]	Granular flow Granular chute flow Sheared granular flow Vibrating granular layer Granular ratchet Horizontal size segregation Balls in rotating cylinder [3D]
Molecular dynamics Soft disk fluid Soft sphere fluid [3D] Rigid body fluid Elastic ball [3D] Vector spin model Self-assembling Soma cube [3D]	Fractals Mandelbrot set Fractal landscapes [3D] L-systems
Monte Carlo Ising model Traveling salesman problem Diffusion-limited aggregation	Patterns Cellular automaton Diffusion controlled chemistry Penrose tiling
Chaos Multiple scattering Lorenz attractor	Miscellaneous Balls in a maze [3D] Hexapod bugs [3D] Abstract machine [3D] Spirals [3D]

Notes

• The set of applets accessible from this page is always under development; since the documentation is rather concise, the reader is assumed to be familiar with the material treated.
  
  
• The files to be downloaded are relatively small (5-25K).
  
  
• Resizing a window that contains an applet should be avoided since it can cause confusion.
  
  
• Actual performance (there may be a lot of computation required) depends not only on the computer (processor and graphics card) but also on the local Java software.
  
  
• The applets have been tested on various systems at different times. The present set are known to work with Java, version 6, under Linux and Windows (use of a recent version of the freely-available Java runtime system from www.java.com is recommended). Note: users of Firefox 3 under Linux should obtain Java update 14 and link to plugin jre/lib/i386/libnpjp2.so instead of libjavaplugin_oji.so (see release notes), otherwise the applets may not function correctly.
  
  
• The applets that use Java 3D software (from java3d.dev.java.net) are known to work with version 1.5.2.
  
  
• The author will appreciate hearing about any problems that are encountered.