To Mars in 70 days: Expert discusses NASA's study of paradoxical EM propulsion drive

Discussion in 'Astronomy, Exobiology, & Cosmology' started by paddoboy, Dec 7, 2016.

1. Q-reeusValued Senior Member

Messages:
3,010
Calling you out. Link to the actual posts that would back your fool claim. Because then I will humiliate you and link to the relevant post(s) supporting me.

to hide all adverts.
3. paddoboyValued Senior Member

Messages:
21,703

So your saying that no known law of physics will be broken whether this is proved to be a goer or a no goer, as they claim,
In other words if it is a goer, then there obviously is some as yet unknown situation afoot.
While I'm here, what are your thoughts on the following paper.......

https://arxiv.org/pdf/1604.03449v1.pdf

Testing quantised inertia on the emdrive:

Abstract:

It has been shown that truncated cone-shaped cavities with microwaves resonating within them move slightly towards their narrow ends (the emdrive). Standard physics has no explanation for this and an error has not yet been found. It is shown here that this effect can be predicted by assuming that the inertial mass of the photons in the cavity is caused by Unruh radiation, whose wavelengths must fit exactly within the cavity, using a theory already applied successfully to astrophysical anomalies such as galaxy rotation where the Unruh waves have to fit within the Hubble scale. In the emdrive this means that more Unruh waves are allowed at the wide end, leading to a greater inertial mass for the photons there, and to conserve momentum the cavity must move towards its narrow end, as observed. The model predicts thrusts of: 3.8, 149, 7.3, 0.23, 0.57, 0.11, 0.64 and 0.02 mN compared with the observed thrusts of: 16, 147, 9, 0.09, 0.05, 0.06, 0.03, and 0.02 mN and predicts that if the axial length is equal to the diameter of the small end of the cavity, the thrust should be reversed.

5 Conclusion
More than eight tests in four independent labs have shown that when microwaves resonate within an asymmetric cavity an anomalous thrust is generated pushing the cavity towards its narrow end. This force can be predicted fairly well by using a new model for inertia (MiHsC) which assumes that the inertial mass of the photons is caused by Unruh radiation whose wavelengths have to fit exactly inside the cavity so that the photons’ inertial mass is greater at the wide end. To conserve momentum a new force appears to to push the cavity towards its narrow end, and the predicted force is similar to the thrust observed. MiHsC suggests that the thrust can be increased by increasing the input power, the Q factor, or using a dielectric. As a direct test MiHsC predicts that the thrust can be reversed by making the length L equal to the width of the narrow end.
++++++++++++++++++++++++++++++++++

Your view would be appreciated as it seems you are probably the only one really qualified either way to comment.
Thanks.

to hide all adverts.
5. paddoboyValued Senior Member

Messages:
21,703
From that paper at post 17, the following is the point that I believe will be shown to be valid.........

"We consider the possibility that the exhaust is in a form that has so far escaped both experimental detection and theoretical attention".

to hide all adverts.
7. Q-reeusValued Senior Member

Messages:
3,010
One can start here: http://www.sciforums.com/threads/em-drive-doesnt-defy-newtons-3rd-law-after-all.156764/
and just work through. And, as a point of obvious embarrassment to your brown-nosing appeal in #22, take note of #6 there. Not that appeals to any authority is my style - but since you like that route....

Messages:
21,703
9. paddoboyValued Senior Member

Messages:
21,703
https://arxiv.org/pdf/1505.06917v1.pdf

Einstein-Maxwell equations for asymmetric resonant cavities:

Abstract:

We analyze the behavior of electromagnetic fields inside a resonant cavity by solving Einstein– Maxwell field equations. It is shown that the modified geometry of space-time inside the cavity due to a propagating mode can affect the propagation of a laser beam. It is seen that components of laser light with a shifted frequency appear originating from the coupling between the laser field and the mode cavity due to gravity. The analysis is extended to the case of an asymmetric resonant cavity taken to be a truncated cone. It is shown that a proper choice of the geometrical parameters of the cavity and dielectric can make the gravitational effects significant for an interferometric setup. This could make possible to realize table-top experiments involving gravitational effects.

10. paddoboyValued Senior Member

Messages:
21,703
From the OP article:

Q. Is there anything else you would like to share about the EM Drive to help us understand?

A. No, but over my professional life I have seen several of these exciting experimental or theoretical results reported in peer-reviewed literature. So far only the reality of black holes has come through. So, based on my experience, the probability of this holding up under further analysis and testing appears slim. But it's not zero.

11. danshawenValued Senior Member

Messages:
3,950
What an excellent thread.

Newton's third law never really specified, 'action relative to what?', or 'reaction or acceleration relative to what?' It also neglects spin, or rotation, both quantum and classical, as well as time dilation, which depends ONLY on instantaneous velocity, not acceleration in the physical if not mathematical universe.

But we know what, don't we? It is a mass acting against subdivided parts of itself, and if those parts of itself are subdivided and accelerated to within a fraction of the speed of light, it's akin to pushing against a wall WHICH CANNOT MOVE FASTER, no matter how much energy is put into it. Converting the rest frame for bound energy into something arbitrarily close to c requires energy expenditure in excess of total conversion of rest mass into energy. Or doesn't it? The vacuum isn't 'really' inertialess either. Quantum spin / entanglement energy of the vacuum also needs to be taken into account. Hint: it's rather a lot bigger amount of energy than you think. It also does not default to spinning in only one direction. Even a quantum spin of zero is RELATIVE to something that is not spinning, and that can occur iff there exist equal and opposite spin components, even for relativistic vector spin addition.

Now do you understand why my posts rag on and on about bound vs unbound energy and the origin of time? No? Didn't think so.

If a thruster could make use of quantum spin energy, likely we wouldn't still be tinkering with rocket engines. And we would not require Newton's third law to make something massive or energetic enough to push against.

Gravity already works like that. Guess Newton never really reconciled that idea with his third law either. I wonder why?

Nature worked all of this out long before evolution gifted us minds capable of manipulating symbols to imperfectly represent or discuss the situation. It knows what the real difference between kinetic and potential energy is, and why exactly it is conserved. You think you have a better handle on it with your incomplete Lagrangian or Hermitian dynamics? Or Newton's second or third law? Think again. You have to get his first law right first. Energy and time IS inertia. But the speed of light is not the fastest process in the universe. Not by a long shot. To answer that question, you must first understand what time is.

Finished trashing the ideas of Newton and Einstein. Carry on.

Last edited: Dec 15, 2016
12. Q-reeusValued Senior Member

Messages:
3,010
So I wasted time skimming through the V2 available at: https://arxiv.org/abs/1505.06917v2
Somewhat sophisticated BS, but BS that could impress anyone lacking a real feel for the worth of the arguments and impressive looking equations. It's clear the author has no sense of what even an average experimentalist would recognize as a hopelessly impractical pipe-dream. With no chance of observation even if the BS theory held water.

danshawen likes this.
13. danshawenValued Senior Member

Messages:
3,950
I don't think it's hopeless (a reactionless thruster), but you aren't going to build one with a wheel of pivoting hammers. Or microwaves. You can achieve thrust with respect to vacuum energy by changing unbound energy of the vacuum into bound energy (matter). Have we done that yet?

We've learned to fly through the air with jet thrusters and aerodynamics. We've also used gravity to slingshot spacecraft. Plans for using solar sails are in the works. So far, so good. You need to crawl before you can walk efficiently and safely.

Last edited: Dec 15, 2016
14. billvonValued Senior Member

Messages:
13,847
Photons escaping should be easily detectable with a spectrum analyzer. It should also be quite easy to calculate the amount of momentum such photons would impart (see photonic thrusters.)

danshawen likes this.
15. rpennerFully WiredRegistered Senior Member

Messages:
4,833
The "dark diphoton" invisible exhaust model has a few theoretical problems too.
Pairs of photons don't cancel at the dark spots on interference patterns, their wave functions do. That's why you get interference patterns even if your photon source is so weak only one photon is in flight at any time. The dark spots are simply where the photons are not.
Bound pairs of photons are still photons and couple to the electron field. Thus there is no reason for the metal of the cavity to be transparent to them, especially at 1937 MHz.
Nothing in physics just turns on in the laboratory. A photon-photon coupling like this would have observational implications for electromagnetism long before the EM drive apparatus.
Conservation of momentum requires that emission of bound pairs of photons would cost no more momentum than the lost photons would, limiting the momentum per energy (thrust per watt) to 1/c or 0.00334 millinewtons per kilowatt which is much smaller than the reported value of $1.2\pm0.1\, \textrm{mN}/\textrm{kW}$.

Last edited: Dec 15, 2016
danshawen likes this.
16. nebelValued Senior Member

Messages:
1,239
just to mention that a current New Scientist article attributes the "thrust" measured to interaction with the Earth magnetic field, not asymmetric interior forces.

Messages:
3,010