Re: Doppler Effect Question

[Hugh Haskell <hhaskell@MINDSPRING.COM>]

>         Your muddying the water.  Your first answer is correct as
> far as it goes.
> I demonstrate the Doppler effect with an apparatus I build using one of
> those obnoxious solid state beepers from Radio Shack. (As my musical
> friends tell me, they are obnoxious because they produce a pure sine wave
> and not a musical note, but this makes them ideal for this demonstration.)
> It is mounted on a small piece of wood with an nine volt battery, The wood
> is fastened to a stout cord so that it can be sung around my head. The
> students in the class hear the Doppler effect as it changes speed in their
> direction. I, at the center, hear only a small effect since my ears are not
> exactly at the center of rotation.
>         One of the real powers of the method of analysis we use in
> physics is that
> we are always making simplifications, when you start relaxing those the
> answers can quickly become murky. Since I have two ears, I probably can
> hear some phase variation as well, but I have always attributed most of the
> change to the small velocity component because the ear is not at the
> center. If I make the string truly at the center of my head will I also
> hear a beat do to the opposite Doppler effects in each ear? Into the
> mud we go!
>
> Gary
> Gary Karshner

Thanks, Gary, for bringing this thread back to reality before it got
completely out of hand. We on this list like to spend a lot of time
wallowing in the mud of complexities far beyond those envisioned by
the original questioner. I marvel at the number of times that, by the
time a thread is finished the originator of the thread has learned
far more than they ever wanted to about the subject.

Not that the mud is unimportant, or uninteresting. I, as a frequent
lurker (and less frequent contributor) on many of the threads, have
often learned a great deal that I hadn't realized before and I value
that. But we often forget that these complexities, while interesting
to us, often only serve to confuse the person who had the original
question. I certainly don't want the contributors to this list to be
bashful about contributing their complexities (as if I could!), but
it is important for all of us to remember that, while it is
interesting and important to know that almost any problem has
complexities that lies below the surface, one must start with a
simpler model and only add the complexities once the simpler model is
understood.

Hugh
--

Hugh Haskell
<mailto://hhaskell@mindspring.com>

Let's face it. People use a Mac because they want to, Windows because they
have to..
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