"cavelamb" wrote in message
...
Rich Grise wrote:
On Sun, 20 Sep 2009 17:26:04 +0000, David Lesher wrote:
"David R.Birch" writes:

4. Who is Feynman?

Andrew VK3BFA.
-100 points for you!
http://en.wikipedia.org/wiki/Richard_Feynman
More importantly; read up on Feynman and the sprinkler problem.....

http://en.wikipedia.org/wiki/Feynman_sprinkler

Why is that a problem? When sucking the fluid out, the pressure on the
"nozzle" side is reduced, so the pressure on the opposite side _pushes_
the sprinkler arms "in reverse". Probably not as fast as the jets would
push it forward, but it seems ovbious that it would turn "in reverse".

It's like sucking an egg into a milk bottle. The milk bottle doesn't
"suck" anything - atmospheric pressure _pushes_ the egg into the bottle.

To do this experiment, you need an old-fashioned milk bottle, or any
bottle whose mouth diameter is slightly less than the minor diameter
of a boiled egg. Light a piece of paper, drop the burning paper into
the bottle, and set the egg on top.

Cheers!
Rich



If you say so...

But let's see you "push" it back out!

Easy.
Drop a piece of dry ice in and hold the bottle neck down.

Paul K. Dickman