Tuning with Physics at the Exploratorium

Overtones are produced by differing wave behaviors as seen in the picture below. The waves have more nodes and antinodes, which change the wavelength. The formula V=Fλ, with V being the velocity of sound, F being the frequency of waves, and λ being the wavelength, states that frequency and wavelength are inversely proportional. When the number of nodes and antinodes increases, the wavelength decreases, therefore increasing the frequency. Pitch is directly proportional to frequency and it rises as a result, creating overtones of different pitches.

Photo obtained from http://netzero-usa.com/site/media/harmonic-levels-and-harmonic-filtration-energy-management-systems-from-net-zero-usa.jpg

When the tunning fork is struck, it produces its fundemental tone and series of overtones. The overtones can be heard in different locations along the tuning fork, which is why different pitches can be heard when moving your head between the prongs. Eventually the overtones can no long be heard but the fundemental pitch is still audible. The fundemental pitch can then be used to accurately and easily tune instruments. Below is the description of the "Big Tuning fork" exhibit at the San Francisco Exploratorium.

Photo taken by Ms. Stefan

And finally, a picture of the Tuning Fork itself:

Photo obtained from: http://exs.exploratorium.edu/wp-content/uploads/2009/10/102_0288-167x300.jpg