This applet shows slow motion of light entering a prism.
Use the mouse to change the shape or the light source ([b]drag arrow[/b] to change position and direction).
Then click [b]play[/b] to see the slow motion of light path.

VIEW or DOWNLOAD ejs xml source
then click to translate strings for selected locale.

Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop.