• Two-Slit Photon: New module added.

There is no new download for this version. (Version 6.1)

• Photoelectric Effect Module: New module added.
• All: Major changes in the Website.

The download has been updated. (Version 6.0.0)

• Geometrical Optics: Added Magic Screen feature to show virtual rays (displayed in yellow). Added On/Off button to toggle the source display. Added a viewpoint.

There is no new download for this version. (Version 5.0.2)

• Geometrical Optics: Added Ground Glass Screen feature. Added "F" source. Changed colors of rotating source.

There is no new download for this version. (Version 5.0.1)

• Planar Waveguide Module: New module added.
• Geometrical Optics: Added Unknown Lens feature. Added "Hide/Show Widgets" button. Removed "New Rays" button.

The download has been updated. (Version 5.0.0)

• Geometrical Optics: Fixed problem of input panels not displaying after loading scripts.

There is no new download for this version. (Version 4.9.6)

• Geometrical Optics: Fixed problem of image flickering when playing back a script containing dragging of the observation screen.

There is no new download for this version. (Version 4.9.5)

• Geometrical Optics: Changed labels on Donut Stop input panel to "Inner D" and "Outer D".

There is no new download for this version. (Version 4.9.4)

• Geometrical Optics: Fixed problem of image dimming at image point. Added scripting for the screen transparency widget. Fixed problem with Donut Stops' radius dragging widgets.

There is no new download for this version. (Version 4.9.4)

• Eye: The physical model for the eye has been improved; values are now consistent with standard optometric data. Note that the maximum focal length is now properly different from the length of the eye in the case of normal vision, because the eye is filled with water and not air.
• Wave: Changed the default amplitude and wavelength for new point sources to be the same as the values used for the two present when the module loads.
• Geometrical Optics: Improved the behavior of the screen transparency widget. There is still flakyness here; some extraneous output may occur, and some futzing (with the screen size widget) may be needful to get things working entirely correctly.
• All Modules: Increased the time period allowed for the VRML scene to finish loading before deciding that an error has occurred; this should reduce the frequency of arbitrary load-failures.
• All Modules: Hiding the navigation panel (with the red button) once again properly hides the viewpoint-selection icons as well as the navigation controls.
• Grating: Reduced the sensitivity of the pan and zoom controls.
• Two/Three Media: Adjusted the predefined viewpoints, principally to get the scene out of the navigation panel.

There is no new download for this version. (Version 4.9.3)

• Grating: Allowed subtler Intensity Factor changes. Improved handling of user-defined lamps. Changed script format to allow easier changes to the list of predefined lamps. Note that most scripts recorded with previous versions of this module will no longer play correctly; see the Troubleshooting Page for more information.
• Fabry Perot: Added a angle and intensity readout accessible by moving the mouse over the screen.

There is no new download for this version. (Version 4.9.2)

• All Modules: Removed extraneous debugging output.

There is no new download for this version. (Version 4.9.1)

• All Modules: Improved efficiency of the navigation panel, particularly for recording scripts. Resulting scripts will be as little as half the size of old scripts.
• All Modules: All modules now support the viewpoint reset feature: if the navigation panel becomes inaccessible (because it is behind an object in the scene), click on the console and press F12 to restore the default viewpoint. Note that this is not meant for general use and may not interact well with script recording.
• Polarization: New waveforms are now introduced into the scene at the speed of the light waves; this creates a more natural and more physical appearance for the electric field vectors. Added an option for displaying the histories as continuous traces rather than sets of dots.
• Fabry Perot: Reversed the sense of the reflectivity widget; reflectivity now increases when the widget is dragged to the right.
• Michelson: Added a position and intensity readout accessible by moving the mouse over the screen.

There is no new download for this version. (Version 4.9)

• All Modules: Several more directions and theory pages have been uploaded, and minor changes made to many of those already existing.
• All Modules: Many of the example scripts have improved accuracy and play faster. Some are also much smaller in file size.
• Polarization: A bug has been fixed that prevented access to one section of the in-depth theory pages.
• WSL: Removed the scripting library's dependence on the Microsoft JVM in anticipation of better cross-platform support. The new version of the scripting library (version 3; version 2 was completed long ago, as described below, but was never released) is available as an upgrade to the existing library. (Real Soon Now there should be a proper installer for it, which will replace the current one for version 0.) Everything is still compatible all around.

There is no new download for this version. (Version 4.8)

• Geometrical Optics: Fixed a problem with loading Donut Stops from a script. Moved the 'T at infinity' to the same position as the 'point at infinity' (keeping its angular size constant).

There is no new download for this version. (Version 4.7.1)

• Geometrical Optics:
  • Added a GUI element for the angle of the rotation source.
  • Made mouse position readout for the rotation source three-dimensional.
  • Added a new kind of optical element, the Donut Stop.
  • Changed color of observation screen.
  • Added widget to control transparency of observation screen.
  • Fixed some scripting problems.
• Fabry Perot: Re-wrote module to use modern libraries. Improved low-resolution rendering accuracy.
• Other Modules: Updated many things (more details forthcoming).
• WSL: Updated to version 3.2; this version has a simpler and cleaner playback system (which fixes some bugs), as well as having a new state system -- in particular, the 'reset' button will now be more rational in how it acts as well as when it can be pressed.

There is no new download for this version. (Version 4.7)

• All Modules: Fixed a minor and occasional problem with the navigation panel.
• Fabry Perot: Many small changes for consistency with other modules.

There is no new download for this version. (Version 4.6.9)

• Documentation: Small corrections and additions were made to most of the documentation in the site.

There is no new download for this version. (Version 4.6.8)

• Scattering: Fixed a bug in reading the initial conditions in a script.

• Michelson: Fixed the bug that caused updates to be much slower when phi was 0.

• Documentation: Small corrections were made to most of the documentation in the site.

• Reflection and Refraction Vectorial: Made the play speed field accessible irrespective of polarization. Redesigned GUI.
• Michelson Interferometer: Fixed the distance field's range (which was +/- 0.01 cm) to agree with the widget (+/- 0.02cm). Disabled input boxes during script playback.
• Two/Three Media: Fixed the rendering of the media divider lines while a widget is being dragged. Fixed the problem with animation starting when pool resolution is changed.
• Scattering: Disabled widgets during script playback.

• Reflection and Refraction Vectorial: Fixed wave velocity problems with unpolarized light. Fixed a bug that would occasionally misdisplay reflected polarized light.

• Reflection and Refraction Vectorial: Fixed an animation problem in the unpolarized mode (introduced in version 4.6).
• Polarization: Restored the ability to play scripts involving unpolarized light (accidentally removed in version 4.5.3).

• Reflection and Refraction Vectorial: Improved the speed with which widgets update the scene.

• Reflection and Refraction Vectorial: Re-released the module: the Java panel and the VRML scene have been retuned, and many minor problems have been addressed, particularly with resetting the module and with scripting.
• General: Retroactively changed to major.minor[.revision] version numbers for greater flexibility.

• Reflection and Refraction Vectorial: Added option to display plane of incidence.

• Two Media: Removed "Animation" button from panel, corrected the labels on Wave Visibility button and set the labels to update during script playback, scripted "Hide/Show Vectors" button.
• Three Media: Removed "Animation" button from panel, fixed "distance" variable updating upon script load problem, added and scripted "Hide/Show Vectors" button, set Wave Visibility button labels to update during script playback.
• Reflection and Refraction Vectorial: Moved incident angle plate in "Perpendicular" mode so Eperp vectors are not under the plate.

• Two Media: Fixed initial angle problem and the problem of the reset button not updating the values in the number boxes.
• Waves: Fixed angle and phase widget feedback problems for linear source and changed maximum angle for a linear source to 360 degrees.

• Circular: Added Obstacle mode.
• Polarization: Removed Wave Plate option from Unpolarized mode.
• Reflection and Refraction Vectorial: Fixed recording of initial phase of the wave.

• Geometrical: Fixed ray density problem with "Point at Infinity" and "T at Infinity" sources and fixed ray-ring problem that occurred while using the "T at Infinity" source and dragging a lens.
• Circular: Removed wave line.

• Geometrical: Fixed problem of added lenses being displayed in the wrong position.

• Geometrical: Added scripting, fixed reset button / lens position problem, added "T at infinity" source, added touch sensor for the source, changed the maximum diameter of lenses and stops to 10cm, added S and S' status bar display for lenses.
• Waves: Fixed sampling stick value update problem when using selection box.
• Rayleigh: Fixed maximum angle problem.

• Circular: Fixed unit problem.
• Reflection and Refraction Vectorial: Fixed WSL scripting playback pause problem.

• Reflection and Refraction Vectorial: Fixed phase widget reset problem.

• Geometrical: Fixed problem of changing diameter of stop with widget and source/reset update problem.
• Reflection and Refraction Vectorial: Fixed change of wavelength type-in box problem and changed inital play speed to 1.0.
• Waves: Fixed phase range problem.

• Geometrical: Fixed focal length field for diverging lenses.
• Waves: Fixed scripting of sampling stick position fields; fixed aliasing problems with removing and then adding widgets. Fixed linear source's angle field.
• Two/Three Media: Fixed crasher bug with loading a script involving animation.
• Polarization: Fixed various problems with wave plate thickness field.
• Scattering: Fixed feedback with certain widgets.
• Many Modules: Improved input field labelling.

• Geometrical: Fixed bad ray patterns appearing during a drag.
• Rayleigh: Fixed diameter display problems.

• Polarization: Switched module to use NumberBoxen; fixed support for resetting the module in a script.

• Waves: Fixed sampling sticks' display of wave heights during animation.

• Rayleigh: Fixed display of minimum angle.

• Polarization: In Unpolarized mode, fixed module to remove wave plates and fixed initial intensity display. Fixed wavelength text field's maximum. Increased default spacing between filters to improve visibility.

• Scattering: Bugs with the theta and phi widgets fixed.
• Geometrical: Greatly improved speed of module; added support for diverging lenses. Further updates and refinements to come shortly.

• All Modules: Many minor bugs fixed.
• Lasers: Updated the Theory page to describe recent updates.
• Fabry Perot: Some interface improvements.
• Waves: Simplified animation interface. Added support for sampling sticks (they read out the pool's height); to be further described in forthcoming update to the directions page. Fixed crashing bug (widgets may now be safely handled during animation).
• WSL: Modified programmatic script-loading interface to simplify automatic script loading from HTML.

• Lasers: Added support for convex mirrors; improved stability checking.

• Waves Reflection/Refraction: Renamed this module to Waves Two Media.
• Waves Three Media: Added this module. This replaces the TIR "module", which is now accessible as an example for the Waves Two Media module.

• Circular: Added the ability to read the intensity on the screen with the mouse; added a plot of the intensity across the screen.
• Transmission Grating: Changed the default lamp to helium and increased the maximum number of grooves for better line resolution.

• All Modules: Re-released all modules with various improvements and bug fixes. The script used for rendering the menus was improved.

• Rayleigh and Circular: The VRML files have been updated to fix problems with the coloring. Many wavelengths of light now render much more smoothly.
• Rayleigh: Various optimizations have been made in the rendering; the module responds more smoothly to widget drags.

• All Modules: Updated the JAR files to fix various problems and add features. Simplified the loading of example scripts. Corrected some of the HTML files. Added directions, examples, and exercises for several modules.
• WSL: A new version of WSL is in use; it provides more feedback on script problems and allows for simpler module code. A new version of the trusted library (the "recording feature") that makes the most of this new version will be available soon; however, the version of the trusted library heretofore available is completely compatible with the new version of WSL.

• All Modules: Internal standardization increased; various bugs corrected.

• Polarization: Updated to enhance phase difference widget.
• Scattering: Updated to enhance widget behavior.
• Waves/Reflection Refraction: Minor corrections.
• TIR: Added a direct link to the TIR mode of the Reflection/Refraction: Waves module.

• All Modules: The JAR files have been changed to allow for new module organization and to prepare for forthcoming enhancements.

• Eye Module: Minor corrections.

• Eye Module: Scripting support added.

• All Modules: Adjusted the size of the simulations to take advantage of more screen space.
• All Modules: Fixed (I hope) the bug that makes the menu bring a blank page.

• All Modules: Changed the menu for accessing all modules. Made some small corrections on all modules. Added the Geometrical Optics Module and the Reflection/Refraction: Waves Module.

• Eye Module: Added.
• Beta Testing: Version 2.30 with new menus accessible at http://webtop.msstate.edu/new/ (Note: That beta test has concluded. Please refer to the main page.)

• Transmission Grating Module: Added.

• All: Improved the recording feature. After this change, the recording feature must be installed only to save your own sessions. Users can play scripts that are placed on the server.

• Scattering: Miscellaneous bug fixes.

• Single Slit, Circular, and N-Slit: corrected minor typos.
• Scattering: Some bug fixes. Added associated pages.

• Reflection: Now loads automatic scripts properly.
• Scattering: Scripts-automatic load does not work yet.

• Rayleigh: Corrected title in theory page.
• Michelson: Corrected the exercises page.
• Polarization: Corrected the exercises page.
• Reflection/Refraction: Corrected the exercises page. Scripting support added.
• Scattering: Added examples page and scripts.
• Waves: Corrected the exercises page, the theory page and the examples page.

• Single, N-Slit, Circular, and Rayleigh: Added "reset" and "hide widgets" buttons to the console.
• Michelson: Corrected the script for example 3.

• Scattering: Improved screen visibility; added support for scripting.
• Polarization: Made the polarizers more visible.
• Reflection/Refraction: Corrected example text.

• Wave Simulation: When loading a script, the line source's angle now is set correctly.
• N-Slit: The wavelength wheel now currently increases its value when turning clock-wise.
• Michelson: The "distance" wheel now correctly decreases its value when turned clock-wise.