Experiment with light and vision, sound, and hearing.
Our eyes and ears respond to light and sound waves, but these are just the first steps in perceiving the world. Playing with light and sound is the best way to learn how they work. Investigating real phenomena can also give you a deeper understanding of the scientific process.
Here’s an exhibit where watching is at least half the fun. You can create any number of gravity-defying illusions that will amaze you and your friends: Levitate, fly, swim though the air, grow limbs (and dissolve them), crawl straight up the wall like a lizard—the sky’s the limit.