On Thu, 16 Sep 1999 13:39:35 -0400 "Robert A. LaBudde" writes: > >It is my understanding that a sound generated from a single point >would >propagate by spherical (not hyperbolic) waves, which can be >approximated by >plane waves at long distances from the source. > True, I'd expect the sound to travel out in a sphere. However, the curve you get where the DIFFERENCE in distance to two points is a constant is a hyperbola. Let's see if I can remember it... I think it's 1 = x^2/a^2 - y^2/b^2 You get various conic sections by messing with this. The minus makes it a hyperbola. Change it to a plus and you get an ellipse where a and b are half the length of the axis. Make them equal and they are the radius of the circle. Harold Harold Hallikainen harold@hallikainen.com Hallikainen & Friends, Inc. See the FCC Rules at http://hallikainen.com/FccRules and comments filed in LPFM proceeding at http://hallikainen.com/lpfm ___________________________________________________________________ Get the Internet just the way you want it. Free software, free e-mail, and free Internet access for a month! Try Juno Web: http://dl.www.juno.com/dynoget/tagj.