Large glass bowl with ping pong balls and violin bow.

Vibrational modes of a thin glass bowl. The apparatus consists of a large glass bowl 12" in diameter, surrounded by a ring of balls near the lip. The edge of the bowl is caused to vibrate in standing wave patterns, by use of a violin or cello bow. The harmonic can be selected by defining nodes on the lip with mild pressure from a finger on the hand not using the bow. Balls residing over nodes will not move while the bowl is being stimulated; balls located over antinodes will vibrate and bounce noticeably.