Posted by Nick Hall (195.74.122.243) on May 05, 2003 at 01:41:44:
In Reply to: Some thoughts and info posted by Vlad on May 04, 2003 at 21:28:05:
Vlad wrote:
:Anyway, basically the whole end point of it is that it shows that you CAN shift the weight of something spinning to a different point on a lever WITHOUT actually moving the weight
This principle was researched by a British Engineer - Eric Laithwaite - in the 1980's. In fact, the principle is not "shifting weight" but rather shifting _mass_ seemingly without the 'penalty' of Newton's 3rd law. In other words, a spinning bike wheel on the end of a rope (as in the demo) rotates with circular motion around the end of the rope from which it is suspended, but the end of the rope does not itself move...you have an 'action' (circular motion) without a reaction (turning force on the pivot itself).
Laithwaite believed this could be used for "thrustless propulsion" and gave a 'celebrated' lecture at the Royal Society. They were not amused and struck the lecture from their archives!
Laithwaite died before fully exploiting the idea (although he managed to patent the principle in the context of a propulsion unit for space travel).
Nick