"Bob Cain" wrote in message

Bob Cain wrote:



Arny Krueger wrote:


Sorry Bob, but I'm not buying.


How about this, then:

1) It is the bulk velocity, the flow of air, at the rest position
that propagates out as the velocity wave.

Frankly, over my head.

2) The bulk velocity at the rest position is the same as the surface
velocity of the piston.

Frankly, over my head.

And, finally:

3) In the frame of reference of the rest position of the
piston, no Doppler shift can be observed.

That seems wrong, because the following is right:

In the frame of reference of the piston, no Doppler shift can be observed.

That's the listener riding the same train as the whistle.