> Henri Kluytmans wrote:
>
> > Brian Atkins wrote :
> > >Interesting article on this in the new Wired 6.03
> > >I remember reading about this a long while back, but it seemed
> > >to be dismissed... now, maybe not.
> >
> > However there is a fundamental problem with gravity shielding,
> > it could be used to construct a perpetual motion machine thereby violating
> > the principle of conservation of energy !
>
> Only if it is an over unity system, which I would doubt. A machine could be
> made to move perpetually, but so long as the sheild is energized. I would
> expect that conservation of energy would mandate that the energy required to
> sheild x amount of gravity would be more than the e/t that could be generated
> from the bias in the field, thus it would still need an external source of
> additionally energy to keep from running down.
So what people are really talking about is a "force field" rather than
a gravity shield. I have tried coming up with a "reasonable" gravity
shield for some science fiction games, but it stumbles on the fact
that once you set up such a shield you could put in as many
gravity-driven devices (like a wheel with one side lighter than the
other) as you want and extract an arbitrary amount of energy from the
shield, even if they are very remote.
I'm very sceptical of this area, I don't see how it could be made to
fit with what we know of general relativity.
-- ----------------------------------------------------------------------- Anders Sandberg Towards Ascension! asa@nada.kth.se http://www.nada.kth.se/~asa/ GCS/M/S/O d++ -p+ c++++ !l u+ e++ m++ s+/+ n--- h+/* f+ g+ w++ t+ r+ !y