Don't Flatten Your Clarinet
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
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.