wow! very interesting applet, it can be used to show reflection . thanks!

i copy here for the benefit of google crawling.

by Ji? Schamberger
After starting the user there are two windows. In the left window is a gray area at the bottom of the reflecting surface (mirror). The position, labeled source flips particles reflected from the reflecting surface, and we will register it in the position labeled detector. Reflections marked with blue, green and red, are some possible paths that particles can pass on the way from the source to the detector.    Control applet in the left window: - When you move the mouse on the source or detector can be moved or source of detector, and their distance is displayed at the bottom of the panel.  - The reflective surface points are located, which can also shift and change as each possible path. Color lines are as follows: red is marked path with the shortest time. Green marked paths that contribute most to the size of the resulting amplitude. The blue color indicates all the other tracks.  - Can be defined wavelength particles.  - Check windows "geometrical " shows run, the impact and fulfilling the law of reflection (yellow).  - Press "Reset" to the applet back to the default state.  - At the top of the panel are: change the number of possible paths. Maximum number is 100   - After pressing the "Random" or "Gauss" you can generate paths randomly across the surface reflection or near the expected rebound with a normal distribution.  In the right window displays the amplitude of the probability of belonging to individual runways and their sum - the resulting probability amplitude.    Instructions to control the right window:  - The shift point on the surface reflection in the left window, click "Recalculation" and the paths are again converted in the correct order (from left to right) - For a better view, use the zoom on the left