Alan Baker wrote:

Nope.

I'm making the point that the upper surface contributes absolutely *no*
lifting force.

None.

Zero.

In fact, it provides a downward force. Every time.



....and you are making the point that when you are breathing in, you are
not SUCKING air at all. It's atmospheric pressure on your chest that
inspires the air. Wow! Who would have guessed? :-)

Brian W