A thin beam of light is often called a ray.
When we stand in the sunlight, some of the light is stopped while other rays pass on in a straight-line path.
A shadow is formed where light ray can not reached.
This java applet let you play with shadow and image.
To make it more fun, there are 3 different colors (Red/Green/Blue) light source.
You can also study the mixing of colored light.
Click different color checkbox to turn on that light source. (Default: Red light)
Click "show trace" button to display light paths.
There is a screen on the left. An object is located between light source and the screen.
Right click the object and drag it up/down to change the length of the object.
If you click the mouse button twice continuously, it is toggle between an object or a slit.
(Use similar method to change the width/location for the slit)
Related web page: Mixing color (Director
Your suggestions are highly appreciated! Please click firstname.lastname@example.org
Author¡GFu-Kwun Hwang, Dept. of physics, National Taiwan Normal University
Last modified : More physics related java applets