Originally Posted By: paul
well , you know talk is cheap , and you can write anything.

but just by writting something doesnt mean anything , it is
only showing that that is what your opinion is on this subject.

you havent shown where any laws have been broken

Actually, kellog and I have been showing exactly which physical law you've been breaking since day 1 - momentum.

Your pipe is a closed system, and momentum is conserved in a closed system.

From wikipedia:

Momentum is a conserved quantity, meaning that the total momentum of any closed system (one not affected by external forces) cannot change. Although originally expressed in Newton's Second Law, it also holds in special relativity

To increase the speed of your pipe - i.e. use it as an engine for a space craft - you need to change its momentum. This is impossible using forces generated within the closed system (i.e. within your pipe).

In order to get a change in momentum of your pipe you must either:

1) Act on it from the outside - i.e. apply a force to the outside of the pipe, or

2) Open the system (i.e. open your pipe) to the outside environment - in other words, make it an open system.

The former requires an outside energy source/source of force. The later turns your device into an overly complex rocket engine.