Create a basic model of the eye, then get into it and use it as a pinhole theater. Learn more about your detector - they eye - by modeling it!
Exploratorium's worksheet on the same idea: http://www.exo.net/~emuller/activities/personal_pinhole.pdf
A classroom activity on detector characteristics - specifically how the eye works!
A worksheet explaining the algebra of color - how color can be treated algebraically in order to see what colors might appear when adding lights or when mixing pigments.
A description of the set-up and conducting of the colored shadow activity.
Using straws and tape you make a simple wave machine.
Toys from Trash version of the Straw Wave Machine: http://www.arvindguptatoys.com/toys/waves.html
The Exploratorium's Straw Wave Machine write-up (more math) http://www.exploratorium.edu/files/ti/alumni/participants/summer_participants_2008/sum084weekphotos/math/course_links/Coupled%20Resonant%20Straws.pdf
Pendulums
Learn the details on making a pendulum snake necklace or a quick pendulum snake with tape.
The Exploratorium's version of the pendulum snake: http://www.exo.net/~donr/activities/Pendulum_Snake.pdf
A worksheet to help you explore and make sense of the pendulum snake.
Worksheet exploring the relationship between length of a pendulum, period of the swing and frequency.
Explore the math behind the pendulum snake exhibit, as well as the math behind pendulum swings!
How to make coupled resonant pendulums.
When two pendulums interfere with one another in a regular manner they are called coupled pendulums. How quickly they interfere with each other - trading off the energy from one pendulum to another is related to their beat frequency. This worksheet explores the beat frequency.
This activity looks at relative motion and inquiry using pieces of PVC pipe.