Hands on is physical. Can't explain the physics of it, but try it.
robo hippy

On Mar 4, 3:06*am, "George" wrote:
"robo hippy" wrote in message

...
George,
You don't have to use sand paper to proove it, use your hand, and feel
the heat differences generated at different speeds and different
pressures.
robo hippy

Sorry, follows the physical laws here. *Must be the latitude.