Bob – although interesting, in this reference Vonsovskii does not mention the
mass of the spin wave. Or if he did, I missed it, so please supply that
reference.
Having real mass could mean everything in the context of understanding why
conservation of momentum is not violated in the Em - and Wallace provides hard
evidence of massive spin waves.
What’s more – Wallace’s mass is within range of the mass-energy equivalent of
microwave photons, which have no rest mass … but apparently microwaves can give
up some of their mass-energy equivalent when they convert into transverse(or
spin) waves.
I am pretty sure we can make the case for magnons being the functional
equivalent of captured spin waves.
From: Bob Cook
Jones--
Spin waves are discussed in the Ferromagnetism book I identified in this
thread--
Ferromagnetic Resonance: The Phenomenon of Resonant Absorption of a High ...
edited by S. V. Vonsovskii
I did not want to raise any more controversy!Smile
Thanks of keeping me in mind anyway.
Bob Cook
From: Jones Beene <mailto:[email protected]>
Sent: Tuesday, March 15, 2016 8:31 AM
To: [email protected]
Subject: RE: [Vo]:Re: EM Drive(s)
A related but alternative bit of insight comes from John Wallace in the cited
paper on spin waves. I thought Bob Cook was aware of it, but maybe not since he
did not bring up the most important detail - mass.
It would be relevant to Shawyer’s drive if the Frustum were to have an iron
liner component, such as an inner layer of sheet iron or even iron plating,
which is not the case, but anyway this paper is worth a read on the off-chance
that copper can produce spin waves like iron (doubtful).
<http://arxiv.org/abs/0901.1631> http://arxiv.org/abs/0901.1631
In Wallace’s hypothesis, applied to Sawyer, RF would be converted into
transverse (spin) waves. These waves have special properties and importantly
they have mass. One dispersion curve yielded a real but exceedingly small
effective mass of 1.8 10^{-39}kg for spin waves… which is not too far removed
from the mass energy of the microwave photon which created it. But unless the
copper frustum acts to release the same spin wave as does iron this explanation
does not work for Em. Plus, since these waves have mass, they can be depleted
over time without a replenishment source which spoils the idea of very long
space missions. Most of the idealists balk at a theory that doesn’t get them
access to intergalactic Sci-Fi missions. J
There are other partial explanations which actually mesh with spin waves.
Shawyer claims that a standing wave interference pattern is created by
geometry, operating frequency path lengths. And he claims that “stress energy
of space” is altered by the interference pattern. That sounds a lot like
aether. A chiral aether with effective mass, together with spin waves of
effective mass – that would explain everything - yet observers shy away. Too
bad.
A third slant is Puthoff's patent - showing that a small but detectable curl
free potential can be created from interference patterns passing through
barriers, presumably like a copper wall. If the microwaves remain inside the
cavity, then there is no interaction with the vacuum except by invoking a
massive wave, and consequently, there is no established theory to give external
thrust to the device except the Wallace approach, which comes the closest since
it predicts wave-particles of low-but-real mass. Wallace does have real
uncontested data for spin waves whereas Shawye’s data is challenged.
Original Message-----
From: Eric Walker
Bob Cook wrote:
If a pulsed magnetic field is involved in the EM drive it may be that effective
momentum is sent off into space as a pulsed magnetic field with some effective
mass associated with the average intensity of the magnetic field pulse—energy
associated with the pulse.
This is along the lines that I was thinking.
Consider a simple thought experiment. We have a microwave waveguide with the
output focused in a single direction sitting out in the middle of space where
there is little in the way of an external field. Attached to it is a battery
sufficient to drive a magnetron at 10 W for some period of time. We turn on
the magnetron remotely. Microwave photons with a total power amounting to 10 J
per second are now being emitted in a preferred direction. For the sake of
argument we will go with the well-accepted assumption that photons have no
mass. Nonetheless they have momentum, and in order for the system to conserve
momentum it will move in a direction opposite the majority of the photons.
We have yet not specified what the system is pushing off of, but I don't think
we need to in order for the thought experiment to work.
Eric
