[AR] Re: Subject: Re: NASA test of quantum vacuum plasma thruster
- From: John Schilling <John.Schilling@xxxxxxxxxxxxxx>
- To: arocket@xxxxxxxxxxxxx, Jake Anderson <jake@xxxxxxxxxxxxxxx>
- Date: Sat, 09 Aug 2014 07:02:52 -0700
On 8/8/2014 10:08 PM, FreeLists Mailing List Manager wrote:
Date: Fri, 08 Aug 2014 17:31:58 +1000
From: Jake Anderson<jake@xxxxxxxxxxxxxxx>
Subject: [AR] Re: Subject: Re: NASA test of quantum vacuum plasma thruster
On 08/08/14 16:04, John Schilling wrote:
>For an ideal photon drive, P/F comes to exactly 299,792,458 m/s.
>
>Sound familiar? Yep. A photon drive becomes a perpetual motion machine
>the moment you attach it to a generator whose armature moves faster than
>light, and no sooner.
>
>Conservation of Momentum, Conservation of Energy, Special and General
>Relativity, they've all got each other's back.
>
That's the thing, the link I posted shows they are getting ~3000x the
efficiency of a photon drive because they bounce the photons back
between a pair of mirrors, which seems to be throwing a spanner into
those works.
Coming up with some spinning system that allows for the same bouncing
isn't really that hard.
So you get a speed of 3MMs / 3K = 100km/sec which is "exciting" but not
ruled out by physics and not enough for red shift to really be playing a
massive role?
or would it, hmm that might kill it off, each bounce the light makes
will red shift it just a little, after 3000 odd bounces it'll wind up
zeroed out.
That sound right to you?
OK, I see the link you posted, and on reflection (heh), I've seen that
before.
Calling that gadget a "photon thruster" is like calling my .45 automatic
a "rocket launcher". The Photonic Laser Thruster uses trapped photons
to transfer momentum between a "launcher" mirror and a "payload" mirror,
just like a gun uses hot gas as a working fluid where a rocket uses it
as reaction mass.
Means you have to add an extra body to all the calculations. As a
further complication, they postulate some applications like formation
flying where the "launcher" and "payload" have identical masses, a
thing rarely seen in gun/bullet combinations. Though that damn fool
.50 BMG pistol someone came up with might come close...
And yes, if you track the energy among the three bodies, what winds
up in the payload comes directly out of the repeated redshifts of the
trapped photons bouncing off the moving mirror(s). If the payload
velocity is negligible, the energy lost to redshift is negligible,
but go back to P = F * V. If the payload velocity is negligible,
the energy transfer to the payload is negligible even if the force
is very high.
That's the bit that tripped up Thomas Gold on solar sailing, so even
very smart people can miss that one if they aren't careful.
John Schilling
john.schilling@xxxxxxxxxxxxxx
(661) 718-0955
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