[extropy-chat] unidirectional thrust

[Mike Lorrey]

Fine, now use the same equations to show how a Bussard Ramjet is also
over unity by your definition.

--- Hal Finney <hal at finney.org> wrote:
> Now I will analyze this thrusting device using relativistic rather
> than Newtonian physics.  A quick review.
> 
> With uniformly accelerated motion, let the proper time as measured by
> the accelerating observer be t' ("t prime").  Let the acceleration by
> "a", and for convenience let us use geometric units where c is 1.
> Then velocities are dimensionless values which are interpreted as
> fractions of the speed of light, and accelerations have units of
> 1/time.
> 
> The standard formulas are:
> 
> x = 1/a * (cosh(a*t') - 1)
> t = 1/a * sinh(a*t')
> v = tanh(a*t')
> E = m * cosh(a*t')
> 
> cosh, sinh and tanh are the standard hyperbolic functions.  x, t, v,
> and
> E are position, time, velocity and energy as measured in the rest
> frame.
> The E term is in geometric units where c=1.  It includes the rest
> energy
> of E=m (commonly written as E=mc^2 when using non-geometric units),
> so to
> get the kinetic energy we would subtract that:
> 
> KE = m * (cosh(a*t') - 1)
> 
> It remains to estimate the acceleration "a".  Mike several times has
> pointed to a document,
>
<http://www.geocities.com/ekpworld/doc/EKP_satellite_maneuvering.doc>,
> which is the only one I have found which actually claimed to have
> measured
> lifter thrust in air and in vacuum.  The author 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 lifter vacuum thrust
> is
> 0.13 times that in atmosphere.
> 
> So, instead of my previous analysis using Naudin's lifter which gave
> 0.3 Newtons of force, I will scale that down by this factor of 0.13
> and take the force in vacuum as 0.039 N.  With a 20 kg device that is
> an acceleration of .00195 m/s/s.  To go to geometric units, we divide
> that acceleration by c and get an acceleration of 6.5E-12/sec.
> 
> Let's see how things are cooking after 60 days of acceleration.  This
> is 5.184 million seconds.  Our device has been drawing 132.9 Watts,
> times 5.184 million seconds is about 690 MJ.  That's how much power
> we've used.

Other errors: you are applying fixed DC when you need to convert that
to pulsed DC and correct for phase angle of the capacitor on the power
factor.

Try these equations:
F= 3.55x10^-8 V^0.722
where F is newtons and V is kilovolts
figure on a thrust to power ratio of 0.00025 newton per applied watt
(not the same as solar panel watt, as turning 12 vdc into 10kv 70 hz
pulsed dc or higher is not quite so easy, plus you need to deal with
the phase angle).

Mike Lorrey
Vice-Chair, 2nd District, Libertarian Party of NH
"Necessity is the plea for every infringement of human freedom.
It is the argument of tyrants; it is the creed of slaves."
                                      -William Pitt (1759-1806) 
Blog: http://intlib.blogspot.com


		
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