"Directions for Gravitational Wave Propulsion
<http://www.gravwave.com/docs/DirectionsForGWPropGraWaV.pdf>" cites the
aforementioned "relatively recent paper on high frequency gravity waves
<https://www.sciencedirect.com/science/article/pii/S1875389212025163>
mentioning
'third time derivative of mass motion'". An evocative excerpt:
"Equation (1) indicates that *the power emitted is proportional to the 6th
power of the frequency*; obviously, the higher the frequency, the higher
the power. Note that the denominator implies that the gravitational waves
will be very weak. For real world materials a different analysis is
required. In fact the actual limit is the ability to keep the emitting
object in rotation (and or vibration) at the highest possible frequency and*
avoiding that it breaks apart because of excessive internal stresses*."
The proposed mechanism conserves momentum with "massive gravitons"
(corresponding to longitudinally polarized gravitational waves):
"In the linearized approximation in flat space-time, GWs are purely
transverse; therefore the interaction of GWs with matter is not useful for
inducing longitudinal motion. In spite of this supposed inapplicability,
the production of gravitons with mass is possible and it is the method that
may permit propulsion by GWs15,31. If gravitons have mass while exiting the
generator, propulsion by conservation of linear momentum is a
straightforward possibility."
Now, I'm not claiming any of this theory is correct, let alone that it is
likely to result in easily observable effects, let alone the explanation
for the phenomenon I encountered in "Weird Fun With Propulsion". But it
does have the appearance of something worth vetting by those sufficiently
motivated to pursue "reactionless" drives.
On Wed, Mar 13, 2019 at 2:43 PM Henry Spencer <hspencer@xxxxxxxxxxxxx>
wrote:
On Wed, 13 Mar 2019, James Bowery wrote:
Keith may recall my "Weird Fun With Propulsion" saga involving anapocryphal
reactionless drive, and the connection with Harry Stine's fascinationwith
"The Fourth Law of Motion" dependent on asymmetric "Jerk" (a=m/s^3).recent
I pretty much forgot about this guy until I ran across a relatively
paper on high frequency gravity waves mentioning "third time derivativeof
mass motion"...
As I understand it -- not a field I'm really up on -- this isn't new:
such things show up with some regularity in General Relativity.
However, this has *zero* connection to any device you can build in
(today's) machine shops or demonstrate in (today's) laboratories.
Gravity is such a feeble force that making such GR effects detectable
generally would require enormous masses moved around at tremendous
accelerations (somehow). This doesn't keep theorists from writing papers
about such devices, but building them is another story.
The apparent similarity to some of the ideas of the reactionless-drive
enthusiasts is pure coincidence. In the (unlikely) event that one of
their gadgets actually performs as claimed, the theory required to explain
this would have to be something completely different.
Henry