[extropy-chat] Relativity drive: the end of wings and wheels?

[Keith Henson]

At 11:04 PM 9/8/2006 -0700, Eliezer wrote:
>Keith Henson wrote:
> > At 06:53 PM 9/8/2006 -0700, you wrote:

snip

> > Thought experiment.  The power you can get out of a moving object is the
> > product of speed and force.
> >
> > So let a vehicle with a reactionless drive on a zero friction bearing
> > accelerate to a high enough speed.  Then you lower a wheel and draw enough
> > power to run the drive.  Let it go a little faster and you are making
> > power.  (This assumes the drive force is invariant to the reference
> > frame.)  QED, a reactionless drive is the same thing as a perpetual motion
> > machine that *makes* power.
>
>Only if the reactionless drive requires no power to run, or if it
>requires less power to run than the corresponding work produced.  They
>made some strange claims, but not that one.

The claim is implicit, a consequence of any claim to have produced a 
reactionless drive.

And no matter *how* much power the drive takes, you can always get more 
power than it takes to run it by going to a high enough velocity.

It's not that I dismiss reactionless drives out of hand, it is just that if 
you have one, it can be used to create energy out of nothing.

Which would be really amusing.

Keith Henson