[extropy-chat] unidirectional thrust

[Hal Finney]

Mike Lorrey writes:
> The error you start off with is that you are using the thrust it
> demonstrates at atmospheric pressure, using atmosphere as the
> dielectric medium. Try first adjusting the thrust to that predicted by
> the dielectric value for vacuum. Fix that error and you wind up well
> within the realm of mundane sub-unity efficiency.... lets try again.

Fine, but it's not going to matter.  Suppose constant power leads to
constant thrust, as the principle of relativity would imply.  Constant
power implies that total energy used will be proportional to time;
but constant acceleration makes velocity proportional to time, and
kinetic energy is proportional to v^2, which means it is proportional
to time squared.  Any time you have input energy proportional to time
while output energy is proportional to time squared, it should be clear
that you will go over unity after enough time.

But if you want some specific figures, I need to know
what value to use for the vacuum thrust.  I looked at
<http://www-personal.umich.edu/~reginald/liftvac.html> and
<http://www.t-spark.de/t-spark/t-sparke/liftere.htm>, both of which
described lifter experiments in vacuum (it didn't lift) but couldn't get
any thrust values there.

Or if you want, I could use that document you pointed to,
<http://www.geocities.com/ekpworld/doc/EKP_satellite_maneuvering.doc>.
He reported a thrust of 2.38 mN in atmosphere and 0.31 mN in vacuum,
with his setup (much smaller than the one used by Naudin).  That would
imply that vacuum thrust is 1/8 that in atmosphere.

Do you want me to do it that way?  Use 1/8 the thrust I did before?
Instead of 0.3 N, about 0.038 N?  It will still go over unity, but it
will take more time.

Just give me the vacuum thrust figure, I'll work it out for you.

I assume you are interested in learning whether this device will violate
conservation of energy?  How will that affect your opinions about it?

Hal