By using a pair of polarizing filters and a property of certain materials called birefringence we can photograph the hidden stresses in hard plastics.
http://www.instructables.com/id/Capture-the-Ethereal-Beauty-of-Everyday-Objects-Us/
A spectroscope is a device that lets us find out what things are made of. It works by taking light and splitting it up into its component colors. Different elements make different colors when they glow.
http://sci-toys.com/scitoys/scitoys/light/cd_spectroscope/spectroscope.html
In this section we will build a toy called the Polariscope. As you can see from the above photograph, the Polariscope creates patterns of beautiful colors, somewhat like a kaleidoscope, but by an entirely different mechanism.
http://sci-toys.com/scitoys/scitoys/light/polariscope.html
In this project, we are going to capture those colorful patterns on paper, in a permanent form, so you can view them anytime you like, without a messy puddle.
http://sci-toys.com/scitoys/scitoys/light/permanent_rainbows/permanent_rainbows.html
In this experiment, students will develop a relationship between light intensity and distance from a point source and a line source
http://www.pasco.com/experiments/physics/april_2003/home.html
Surprise your eyes with this optical illusion
http://pbskids.org/zoom/activities/sci/arrowsopticalillusio.html
Send secret messages to a friend
http://pbskids.org/zoom/activities/sci/mirrormessages.html
Secretly scope out stuff with this spying tool.
http://pbskids.org/zoom/activities/sci/periscope.html
Phenawhozeewhatsee? It's an animation invention that Brianna calls a "Winker".
http://pbskids.org/zoom/activities/sci/phenakistascope.html
The scattering of light by the atmosphere, which creates the blue sky and red sunsets, can be modeled when light from a flashlight shines through clear glue sticks.
http://www.exploratorium.edu/snacks/glue_stick/index.html