PenguiN wrote:


Okay, Bob, I'm going to add a DC component, but I'm not going to
tell you that this DC component is really a millihertz-frequency sine
wave. How will you know the difference? Just what IS the difference
over a time period of one second?

Enough. :-)


Bob


Woah, wait a second, you're hand-waving your way out of this one
without actually addressing it.

Please explain how, exactly, a DC component changes the "source" of
the signal, but when there's an infinitesimally small frequency, so
small that one can't detect it, but that technically is not DC, the
"source" of the signal suddenly "snaps back" to be the center, or zero
excursion point, of the driver?

Because there is a real difference. Air can't carry the DC
component of velocity but it can carry any time varying
component.

It appears to me that Doppler shift is a consequence of that
difference.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein