Conja Summerlin <[email protected]> wrote: On Wed, Feb 10, 2010 at 20:52, Jerry Houston <[email protected]> wrote: Not to mention the loss of heat due to evaporation of your moist breath, the rate of which would depend on the relative humidity of the air in the horn ...
I would expect once the horn has been played a little I would expect the air in most of the horn's length to have similar humidity to breath exhaust. Let's not forget relative barometric pressure. No, let's forget relative barometric pressure. The pressure of a gas makes no difference to the speed of sound in that gas. The _composition_ and temperature of the gas is what makes the difference (including slight effects of relative humidity) but the absence of effect due to pressure is what makes it possible to play the same horn at sea level and in elevated cities such as Denver. In Denver, if you were playing outdoors, the adiabatic temperature would make the temperature about 10 degrees C colder than the temperature at sea level, and this would make a difference. This is why most concert halls have central heating, especially in Denver. At extreme altitudes (e.g. the stratosphere) the speed of sound changes because the composition of atmosphere changes with altitude. But the composition is relatively constant throughout altitudes where it is possible to play. ========== In a vacuum no one can hear you clam. _______________________________________________ post: [email protected] unsubscribe or set options at https://pegasus.memphis.edu/cgi-bin/mailman/options/horn/archive%40jab.org
