On Oct 8, 8:17 pm, wrote:
On Oct 8, 12:37 am, Jim Logajan wrote:





Le Chaud Lapin wrote:

"the molecules stay in contact with the solid body"...?????????????

Why?

It's what gases do. The particles are constantly bouncing away from each
other. This is pretty simple physics - something that should almost be
intuitive. If you have a cylinder of gas with an air-tight piston and pull
back on the piston and double the size of the volume do you seriously think
the gas will not expand into the other half as fast as it can to try and
stay in contact with the piston?

If you are having this much trouble on a basic concept of gases, then I see
no value in you or anyone else investing time in dealing with your
questions, which you chose to post to an inappropriate newsgroup anyway.

Grumble. Now I recall why I had established a personal policy to stay away
from discussions of aerodynamics on this newsgroup: futility avoidance.

I applaud. Very well put.

Not well put.

What Jim is describing here and what I was refuting are two different
things.

Jim is describing why a fluid would have propensity to follow the
piston wall of an expanding cylinder chamber. I have never doubted
that reason the fluid follows the wall is because of intermolecular
bombardment, and with walls...etc.

That was not what I was refuting.

If you read carefully my post, you will see that I was refuting what
the article claims, which is that the fluid follows the piston because
the piston actually pulls on the molecules in the chamber, which, of
course, is ridiculous.

-Le Chaud Lapin-