2000-11-02 10:50
URBANA, IL--While attempting to do some productive work, I got sidetracked by a fellow procrastinator who was trying to figure out why clarinets go flat in the winter, necessitating a shorter neck. Using the all-powerful laws of physics, We figured out a solution.

If you have ever sucked helium from a balloon to make your voice high and squeaky, you already understand how this works. Sound travels faster in lighter gases, like helium. Water (atomic mass 18) is present in the air around us in the form of water vapor, as is Nitrogen (N2, atomic mass 28). In the summer, the humidity is higher, hence more light water vapor in the air. In the winter, it is much drier outside, and there is a higher percentage of heavy Nitrogen in the air.

Since sound moves more slowly in Nitrogen, the wavelength of the sound is longer, and the frequency lower, and the note goes flat. The difference in the speed of sound is so different, that clarinets go so far out of tune, they cannot be corrected by pushing the mouthpiece all the way in, so they need a shorter neck to compensate.

Hope this tidbit satiates your curiosity so you can get back to useful work. As for me, I've gotta go teach.