Alan Baker wrote:
In article ,
Jim Logajan wrote:

Any change in pressure is *by definition* a change in the number of
particles in the fluid that are impacting the surface.

That assertion is incorrect. You are no dummy so I'm sure you'll correct it
when you realize the errors.

Sorry, but it's not. Pressure is created by particle collisions.

Hmmm...looks like Jim expected too much from you: the kinetic theory of
gases has it that pressure may be computed from the temperature AND the
density of gases... that is to say, by retaining the SAME molar quantity
of gas, and raising its temperature (which translates to a higher
velocity), the pressure is increased P.V = R.t and all that....

Put it another way: each "hotter" molecule reverses direction at a
surface with greater force.

Brian W