Hi,

I did say "uniformly ascending mass of air", I didn't say how one got there.

All right. If you put an accelerometer in an ascending mass of air and
then, when it moves with that mass of air, read it, it will show zero.
I concede that :-).

But that is the same thing as saying a vario will read zero when the
pressure around it is not changing.

I cannot quite understand how that relates to "fooling" an
accelerometer. There is no way to get it from lying on the ground
to moving with the uniformly ascending mass of air without it showing
a non-zero value at some point in time.

So, if birds can be made to believe that they are changing altitude by
putting them in a pressure chamber and changing ambient pressure, then
I think accelerometers as sensors are indeed ruled out. At least as
singular source of input.

In these experiments how does one know that the bird thinks it is
climbing or descending? If you put a human into the same chamber it
will likely notice a change in pressure, even if not as small a
change as the bird. But we are rarely able to tell which way, much
less relate the relative change in pressure to absolute change in
altitude.

Designing an experiment where one can make sure the bird translates
pressure change to altitude seems hard to me.

Ciao, MM
--
Marian Aldenhövel, Rosenhain 23, 53123 Bonn.
Fon +49 228 624013, Fax +49 228 624031.
http://www.marian-aldenhoevel.de
"Wie trennt man drei Schlampen von zwei Säufern? Cockpittüre zu!"