At the time when Java was new, and applets were considered a recent emerging technology, lots of scientists have learned Java applet programming just to describe they ideas in the form of visualization. Frequently they were written by people highly competent in the subject being illustrated (biology, physics, higher mathematics) rather than in programming. Where the licensing permits (as a rule, must be open source), permitted, we have collected, reviewed and fixed such applets from the whole web, as well as offering a collection of our own applets. Below, you will find the overview of that we have already done. Few applets only required to find them however programming effort was often necessary to revive them for a second life.
The articles next to applets were editable as well, and some contribution has been received. All applets were running as untrusted (this means, restricted by Java security manager). They were subject by both automated scan during compilation (the modified OpenJDK compiler was checking against the database) and, most important, manual code inspection. Nobody ever attempted to contribute malware of any kind, by the way.
Starting from Java 7 update 51, now Oracle Java virtual machine blocks unsigned applets by default, while they have been running on a web since Java first came on. This essentially disabled the site for the end user who just wants to read articles and view animations, ending the whole project. However we decided not to shut down the site as applet descriptions and they open source code still may be interesting for developers. Also, as now applets cannot be executed, they plain-picture screen shots become valuable.
Contents of this page:
We present several topics on electrophysiology that were written by professionals and once released under GPL. Visualizations on morphogenesis and plant orientation were also written to supplement scientific papers in the past. The flock visualizer reliably shows that a group of individuals may have very coordinated activity without having any leader. Biomorphs illustrate some hypothesis on how the evolution may happen.
Due recent contribution we also have a good introductory series about complex plane and also Besicovitch set and Penrose map from the same source. The interactive demonstration of image processing (2D FFT) is available. On SourceForge we found a nice WMC framework to create visualizations of the simple curves with very little programming, but due us being busy with other parts of the project only parabola and logistic growth have been implemented. Generalized Lambda distribution is our first "extinct" applet that ceased to exist anywhere apart our site. The first applet of our project, Mandelbrot set (kind of something "must to have"), was also a mathematical applet.
Mathematical section also contains a "mystery visualization" of the fundamental domain - the only applet for that we were not able to write any article as did not manage to understand that it is showing. Maybe you could help?
Analog electronics include quite important Poles and Zeros topic about analog filtering of the signal, and how to compute such filters with desired parameters. The collection also contains a single cascade transistor amplifier circuit that allows user to alter many parameters and shows the simulated currents and voltages. Depending on how resistors are set, it can demonstrate the work of both grounded collector and grounded emitter.
In Conway's Game of Life series a single applet shows evolution of various colonies, depending on parameters. The user can pause, step and add or remove cells at any step of evolution. Rubik's cube is a working example of 3D visualization even without any graphic acceleration and could also be configured to show up differently. There is a very comprehensive applet on Sudoku, while seems not very popular for some reason. Dissociated press is just a part of the whole hacker culture. There are also two variations of Tic tac toe.
Ray diagram that we initially took from SourceForge but extended in a number of ways seems the most popular applet in all project. From optics, we also have our own Prism. Also Wikipedia uses a screen shot of our Atomic orbitals visualization that we have contributed there. This group also contains pendulum, the only finished visualization of Labs4Wikiversity, the first active project to use applets systematically in encyclopedic material. We have found unusually well prepared open source visualization and explanation of two dimensional collision. Rutherford scattering, while easy enough to understand, can be very nicely illustrated with the applet. Differently, wave packets brings us into the true physical jungles of the wave particle dualism. Brownian motion, while easy enough to understand without visualization, offers interesting experiments due its "time machine". There are also many less popular but also interesting topics in this category.
Near 30 topics can be directly or indirectly assigned to this category, too many for talking about them all in the front page. Please visit the category page to see them all.
You can just play with applets from this mystery collection, as children do with mandelbrot set. This last group is the attic of the project, and we do not expect to have a lot of visualizations there.