On Thu, 16 Oct 2008 14:19:05 -0700, Richard Clark
wrote:

On Thu, 16 Oct 2008 13:57:44 -0700, Jeff Liebermann
wrote:

Worse, the back pressure created by the
immovable column of sand will force some sand particles into the
conduit around the edges with the "reflected" air pressure.

H E R E S Y

Hershey Bar (Chocolate Rules). Besides, following the orthodoxy lacks
entertainment value.

Reflected waves do NOT have power in them - or so goes the catechism.

This new and dangerous introduction of a side topic can only lead to
endless debate about the superposition phase properties of sand in
vacua (particel theories inhabiting the crevices in the science of
Equal Librium)

Yeah, but I like playing in the sand. Try this experiment next time
you have an air compressor and nozzle handy. Find a cardboard,
plastic or metal tube at least 3 ft long. A vacuum cleaner extension
pipe will suffice. Plug up the other end with whatever is handy. Blow
air into the center of the tube. Run your fingers around the edges of
the tube and note which way the air is flowing. That's what will
happen if the compressed air is not sufficient to blow 30 lbs of sand
into the air. The air and the sand will flow back into the pipe in
the opposite direction as the compressed air.

73's
Richard Clark, KB7QHC

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558