Sound

333 Tricks
pg 9: Tie a string tightly around the glass and loosely around the pencil. Hold the pencil and let the glass hang down. As the pencil is turned, a peculiar noise comes from the glass.

Pg 10: Drive the nails half way into the can, as shown, and stretch the rubber band between them. Pluck the band with the finger and a sound will be heard. Wrap the band around the nails a few times, pluck it, and the pitch heard when the band is plucked will be higher.

Light

Martin Gardner
pg 69: Find the blackest sheet of paper you can and cut out a square about 4 inches to a side. With an ice pick or sharp pencil point, make a tiny hole in the enter of the square. Place the paper on top of a porcelain cup that is all white inside. Under a lamp, the hole clearly is blacker than the paper.

pg 65: Tie a small wight to one end fof a 2-foot length of string. Stand at one end of a room and swing the weight back and forth like a pendulum. A person stands on the other side of the room so that the plane of the pendulum's swing is perpendicular to her line of vision. She holds one lens of a pair of dark glasses over one eye, but keeps both eyes open. The weight will seem to travel in an ellipse. If she shifts the dark glass to the other eye, still keeping both eyes open, the weight appears to go around the ellipse the other way.
pg 70: Fold a black sheet of paper in half twice, then draw a circle about 3 inches across on the folded paper. Cut through all four thicknesses of the paper to produce four black disks. From each disk, cut out a quarter section. Place the mutilated disks on a white surface. Because your brain always makes the best bet in interpreting perceptions in the light of past experience, you will see what looks like a white paper square on top of the disks.

pg 72: With black ink, draw the pattern shown on thin cardboard. Each die face should be about 3 inches on the side. Cut out the pattern, fold it, and tape the edges to make the faces of an inside out die. Place it on a table, stand across the room, and close on eye. Keeping the eye closed, move a few feet to either side. The die seems to rotate in a direction opposite to your motion. Hold the model on the palm of a hand while you stare with one eye at its far corner. In a moment, your brain will snap the die from concave to convex. Now turn your hand in different directions. The die seems to float above your hand, always twisting in directions opposite to the direction your hands turn.


Gravity and Spacetime
Turning The World Inside Out.
Pg 13: Dropping an accelerometer onto different surfaces and from different heights shows qualitatively the dependence of deceleration on the initial speed and the stopping distance.