Visible Effects of The Invisible

Visible Effects of the Invisible graphically demonstrates resonant frequencies. A horizontal, clear glass tube is partially with clear fluid. Sound generated by a speaker housed at one end of the tube causes the air in the tube to vibrate and geysers appear in the fluid where the motion of air is greatest. The geysers are generated at various sections of the tube by the adjusting the resonant frequency of the speaker which causes pressure differentials.

Educational Resources

Resonator
If you vibrate something at just the right frequency, you can get a big reaction.
Slinky in Hand
Model transverse and longitudinal wave resonances. Learn about notes and antinodes.
Finding the Sweet Spot
Use a hammer to find one of the “sweet spots” on a baseball bat.
http://www.exploratorium.edu/baseball/sweetspot.html
Resonant Rings
One reason not all buildings are equal in an earthquake.
TED: Making Sound Visible Through Cymatics
A talk about sound visualization with beautiful examples
http://www.ted.com/talks/lang/eng/evan_grant_cymatics.html