Author Topic: EM Drive Developments Thread 1  (Read 765505 times)

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #860 on: 09/21/2014 07:37 PM »
There is no distinction between the cavity's interior and the (copper ?) metal wall in the COMSOL finite element analysis display of the Electric Field, so my reading of this is that the metal wall was modeled as a Boundary Condition for the field.

1. I need to get back outside where we are laying block.   Rather massive objects indeed.  But I came in for a drink of hydrogen dioxide, and noticed this.

2. If the boundary condition is as Rodal suggests, then what difference does it make what you make the truncated conical frusturm thingy out of?

3. I will be printing our Rodal's expostulation on goatGuy's math.  A quick glance is not enough.

4. I guess I'll be starting a Mach to Sciama to Woodward thread.  As some have pointed outo on this thread, there are equational difficulties with Woodward's derivations.

5. Nous n'avons pas encore inclure le franais dans le mli-mlo linguistique.

6. Just sayin'.
« Last Edit: 09/21/2014 07:38 PM by JohnFornaro »
Sometimes I just flat out don't get it.

Offline ThinkerX

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Re: EM Drive Developments
« Reply #861 on: 09/21/2014 07:41 PM »
Ok, I am getting confused.  (something which is easily accomplished, but even so)

Quote
<<Moving forward, a new tapered cavity RF resonance system has been designed and characterized using COMSOL with Q-thruster physics. Figure 26 shows some of the COMSOL analysis with the higher performance dielectric resonator clearly visible. This resonator material has a relative permittivity that is an order of magnitude higher than our current tapered cavity test article resonator material. The lessons learned with antenna design and location have been factored in and the design of both the drive and sense antennas have been explicitly optimized to excite the RF thruster at the target frequency and mode (e.g., the optimal location has been analytically determined). The thrust performance of this next generation tapered test article has been analytically determined to be in the 0.1 newton per kilowatt regime.>>

Rodal, where did you get this quote from?  Was it in the original paper?

Also:

0.1 newton per kilowatt seems like a big jump in efficiency from the previous design.  Assuming the next round of tests confirms these results,  would thermal heating, pendulum problems, or other obvious errors still be valid alternate explanations?  Especially if said tests were conducted in a full vacuum?

Would the 'electron approach' still be a viable alternate explanation?  Though I am under the impression the electron solution has almost as many problems as the ones involving exotic physics. 

And finally...suppose the next round of tests does confirm a thrust of 0.1 newton's per kilowatt without significant issues from thermal heating, instrument problems, or an abundance of electrons.  Does this mean rewriting part of modern physics?

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #862 on: 09/21/2014 07:44 PM »
Ok, I am getting confused.  (something which is easily accomplished, but even so)
... 

And finally...suppose the next round of tests does confirm a thrust of 0.1 newton's per kilowatt without significant issues from thermal heating, instrument problems, or an abundance of electrons.  Does this mean rewriting part of modern physics?

No doubt but that I am far more accomplished at being confused than you.

Still, let's not sidetrack into rewriting physics.  There is no experimental cause, and the experimentors are silent without cause.
« Last Edit: 09/21/2014 07:45 PM by JohnFornaro »
Sometimes I just flat out don't get it.

Offline Rodal

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Re: EM Drive Developments
« Reply #863 on: 09/21/2014 07:49 PM »
There is no distinction between the cavity's interior and the (copper ?) metal wall in the COMSOL finite element analysis display of the Electric Field, so my reading of this is that the metal wall was modeled as a Boundary Condition for the field.


2. If the [metal walls are modelled as a] boundary condition is as Rodal suggests, then what difference does it make what you make the truncated conical frusturm thingy out of?

....
6. Just sayin'.

It makes just as much difference as for example when you model the end supports of a beam made with material modulus Ea supported inside another material with modulus Eb at both ends:

1) If the modulus Eb>>Ea one is justified to model the beam with Boundary Conditions such that the rotations at both ends are zero. (A beam clamped at both ends)

2) If the modulus Eb<<Ea one is justified to model the beam with Boundary Conditions such that the rotations at each end are free to rotate at will (a beam with simply supported ends) .

3) If the modulus Eb~Ea then one has to model the Boundary Conditions with springs of a given rotational stiffness (dictated by the stiffness Eb).

Lei capisce ?

It's all in how one models the Boundary Conditions.  Maxwell's equations are differential equations, and to solve them one needs to satisfy Boundary Conditions, just as when one solves a beam equation.

« Last Edit: 09/21/2014 08:51 PM by Rodal »

Offline Rodal

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Re: EM Drive Developments
« Reply #864 on: 09/21/2014 07:52 PM »
There is no distinction between the cavity's interior and the (copper ?) metal wall in the COMSOL finite element analysis display of the Electric Field, so my reading of this is that the metal wall was modeled as a Boundary Condition for the field.

................

4. I guess I'll be starting a Mach to Sciama to Woodward thread.  As some have pointed outo on this thread, there are equational difficulties with Woodward's derivations.

...............



WHO is going to be explaining/defending Woodward's derivation ?

Just sayin'.

Offline Rodal

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Re: EM Drive Developments
« Reply #865 on: 09/21/2014 07:55 PM »
Ok, I am getting confused.  (something which is easily accomplished, but even so)

Quote
<<Moving forward, a new tapered cavity RF resonance system has been designed and characterized using COMSOL with Q-thruster physics. Figure 26 shows some of the COMSOL analysis with the higher performance dielectric resonator clearly visible. This resonator material has a relative permittivity that is an order of magnitude higher than our current tapered cavity test article resonator material. The lessons learned with antenna design and location have been factored in and the design of both the drive and sense antennas have been explicitly optimized to excite the RF thruster at the target frequency and mode (e.g., the optimal location has been analytically determined). The thrust performance of this next generation tapered test article has been analytically determined to be in the 0.1 newton per kilowatt regime.>>

Rodal, where did you get this quote from?  Was it in the original paper?


That quote is from the last page of the "Anomalous thrust ..." paper

Offline Rodal

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Re: EM Drive Developments
« Reply #866 on: 09/21/2014 08:04 PM »
Well, if the RF field can not turn the electron stream without a reacting force, then that leaves

1. Dr. White's idea of the electrons/protons appearing and disappearing from/to the quantum vacuum, and
2. The alternative of the real electrons disappearing into the quantum vacuum.

The first idea has been discounted by critics. The second idea has not been put forward, to my knowledge.

Of course there are the ideas put forth by Shayer, and by the Chinese experimental group, as well as new ideas that might be held Boeing and Cannae groups.

Don't forget (what to me looks like) the (most likely) explanation:

the measured thrust forces are due to spurious testing effects and these tested EM drives will not generate any (translational motion) thrust in space.

« Last Edit: 09/21/2014 08:07 PM by Rodal »

Offline aero

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Re: EM Drive Developments
« Reply #867 on: 09/21/2014 09:02 PM »
Well, if the RF field can not turn the electron stream without a reacting force, then that leaves

1. Dr. White's idea of the electrons/protons appearing and disappearing from/to the quantum vacuum, and
2. The alternative of the real electrons disappearing into the quantum vacuum.

The first idea has been discounted by critics. The second idea has not been put forward, to my knowledge.

Of course there are the ideas put forth by Shayer, and by the Chinese experimental group, as well as new ideas that might be held Boeing and Cannae groups.

Don't forget (what to me looks like) the (most likely) explanation:

the measured thrust forces are due to spurious testing effects and these tested EM drives will not generate any (translational motion) thrust in space.

If we are going to accept that it is measurement error (Shayer, Chinese, Eagleworks) then we may as well cut this discussion off now and accept that there is nothing to prove.

I wish I knew the time-line for the IV&V testing.
Retired, working interesting problems

Offline aceshigh

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Re: EM Drive Developments
« Reply #868 on: 09/21/2014 10:06 PM »
There is no distinction between the cavity's interior and the (copper ?) metal wall in the COMSOL finite element analysis display of the Electric Field, so my reading of this is that the metal wall was modeled as a Boundary Condition for the field.

................

4. I guess I'll be starting a Mach to Sciama to Woodward thread.  As some have pointed outo on this thread, there are equational difficulties with Woodward's derivations.

...............



WHO is going to be explaining/defending Woodward's derivation ?

Just sayin'.

only solution would be to Paul March to return here, or for you to join Woodward's mailing list and keep us updated on your scientific arguments with Woodward himself.

Offline 93143

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Re: EM Drive Developments
« Reply #869 on: 09/21/2014 10:10 PM »
Does this mean rewriting part of modern physics?

Not necessarily.  There could be an explanation that doesn't break anything we thought we knew, without rendering the devices useless for space propulsion.

For instance, it has been suggested that these devices are actually accidental Mach-effect thrusters.  The Mach effect, if valid, does not require throwing away any physics; it was derived from a simplified form of general relativity, and should therefore (if valid) be implicit in the full Einstein field equations combined with known cosmological parameters.

It has been said that Mach's principle is known to be wrong, but this is only true for certain interpretations.  It is admittedly not inherent in general relativity by itself, but according to Sciama it just so happens that in an expanding non-empty Robertson-Walker cosmology (that is, the kind we live in), the equations of general relativity just happen to result in something that behaves exactly like inertia.  According to later calculations, this requires the universe's density parameter to be of order unity (the exact number varies depending on how Einstein's equations are approximated), and recent observations of the universe have pegged this parameter at almost exactly one.  Note that there is still no widely-accepted theory of what inertia is...

...

I've been trying to integrate the hypothetical Wheeler-Feynman-type interaction out to the cosmological horizon (not the Hubble radius; that seems to be a misconception) to test my Doppler effect idea, but either I have a mental block or it's harder than I thought (I am not trained in general relativity and was trying to shortcut around the complicated bits)...  also I have a lot of thermodynamic calculus I need to be doing for work, so I can only pay so much attention to this...

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #870 on: 09/21/2014 10:12 PM »
There is no distinction between the cavity's interior and the (copper ?) metal wall in the COMSOL finite element analysis display of the Electric Field, so my reading of this is that the metal wall was modeled as a Boundary Condition for the field.

... 4. I guess I'll be starting a Mach to Sciama to Woodward thread.  As some have pointed outo on this thread, there are equational difficulties with Woodward's derivations.

WHO is going to be explaining/defending Woodward's derivation ?  Just sayin'.

iS IT NOW BEING SUGGESTED THAT wOODWARD'S MATH CANNOT STAND ON ITS OWN?

Hey.  Who locked the caps key?
Sometimes I just flat out don't get it.

Offline frobnicat

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Re: EM Drive Developments
« Reply #871 on: 09/21/2014 10:24 PM »
Compressed hummingbird wings? (Which is real)  Ground unicorn horns? (Which is fake)

Now we are getting at it, I was sure this new tech development would be an ecological disaster of some sort, how many hummingbird to thrust 80 metric tons to Saturn ? As for the (allegedly fake...) later proposition, you think unicorns aren't rare enough to take a toll on their population diversity ?

Quote
The second case is a bit harder to prove, but still within reach of ordinary algebra:

Ek = mV   ... kinetic energy as a function of V, again.
V = at ... again, now substitute
Ek = mat  and remembering that [F = ma]...
Ek = Ft/(2m)

If F = ma, then F^2 = (ma)^2 = m^2a^2, correct?

GoatGuy doesn't write that.  Instead he writes:

Quote from: goatGuy
Ek = mat

How did he get from Ek = mat to Ek = Ft/(2m)?

Apenas dizendo.

Je peux donner un coup de main sur ce petit exercice d'algbre :

F = ma, then F = (ma) = ma, (1) is correct
We want (well, GoatGuy wants) to get rid of a from  Ek = mat (2)
So from (1) dividing left and right by m we can rewrite that F/m=ma/m=a
That is a=F/m (really we could simply have squared a=F/m to get this one)
Substitution of a by F/m in (2) yields :
Ek = m F/m t =  (m F t) / (2 m) = (Ft)/(2m)  (divide numerator and denominator by m)

CQFD : Ce qu'il fallait dmontrer.

Quote
Nous n'avons pas encore inclure inclus le franais dans le mli-mlo linguistique.
Was almost perfect French, just "inclure" is present infinitive while here we need "participe pass" : "avoir inclus". Had to look into conjugations tables to be sure of the ending s though !

Offline Notsosureofit

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Re: EM Drive Developments
« Reply #872 on: 09/21/2014 10:25 PM »
Where does one find Woodward's math ?  It would be interesting to see how it compares to a General Relativity interpretation.

Offline Rodal

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Re: EM Drive Developments
« Reply #873 on: 09/21/2014 10:42 PM »
Where does one find Woodward's math ?  It would be interesting to see how it compares to a General Relativity interpretation.
Excellent question.  From what I found so far:

1) Woodward's derivation uses a flat Minkowski space.  In that sense he does not use Einstein's General Relativity.  He uses Special Relativity (and says so in a number of places). There is no curvature of space in Woodward's derivation.  There is no covariant, contravariant or mixed tensors. No Riemannian geometry.
Gravity is given "ab initio" (unlike Einstein's General Relativity where gravity is a result of curving of space by massive objects), yet goes on to postulate transient mass effects due in most part to most distant objects.  The justification appears to be isotropy of spacetime and local flatness of spacetime.

2) He uses the [rest energy/volume] relationship to [rest density] Eo=rho c^2 sometimes here and sometimes there.

3) I have not found Woodward's transient mass effect equations in any paper by Sciama.  He apparently uses some results from Sciama's 1953 paper and goes on from there.  From what I can gather Woodward does not use Sciama's 1969 (paper) perturbation of General Relativity.


Many questions...  Perhaps somebody would be willing to explain/correct the above statements
and give a link where Woodward's most complete derivation is contained
« Last Edit: 09/21/2014 11:07 PM by Rodal »

Offline Notsosureofit

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Re: EM Drive Developments
« Reply #874 on: 09/21/2014 10:50 PM »
Yes, but are his papers publicly available and if so where ?

Sorry, didn't mean to sound picky.

OK. So there's a good chance I still have the '64 Sciama here somewhere, at least.
« Last Edit: 09/21/2014 11:20 PM by Notsosureofit »

Offline Rodal

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Re: EM Drive Developments
« Reply #875 on: 09/21/2014 11:20 PM »
Yes, but are his papers publicly available and if so where ?

Sorry, didn't mean to sound picky.
Of the papers that I found in the web, this link (see the Appendix A) has the most complete derivation: http://wqww.theeestory.com/files/Flux_Caps___Origin_of_inertia_04-20-2004.pdf

Yet, not enough for me.  Hope somebody can point to a more complete reference

[Sorry I had the caps key on for a while. It was an accident  :(]
« Last Edit: 09/21/2014 11:22 PM by Rodal »

Offline Rodal

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Re: EM Drive Developments
« Reply #876 on: 09/21/2014 11:30 PM »
[
Je peux donner un coup de main sur ce petit exercice d'algbre :

F = ma, then F = (ma) = ma, (1) is correct
We want (well, GoatGuy wants) to get rid of a from  Ek = mat (2)
So from (1) dividing left and right by m we can rewrite that F/m=ma/m=a
That is a=F/m (really we could simply have squared a=F/m to get this one)
Substitution of a by F/m in (2) yields :
Ek = m F/m t =  (m F t) / (2 m) = (Ft)/(2m)  (divide numerator and denominator by m)

CQFD : Ce qu'il fallait dmontrer.



Ah, je vois !   http://forum.nasaspaceflight.com/index.php?topic=29276.msg1260041#msg1260041




Offline JohnFornaro

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Re: EM Drive Developments
« Reply #877 on: 09/21/2014 11:32 PM »
"oin Woodward's mailing list"

Tried that.  Didn't work.
Sometimes I just flat out don't get it.

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #878 on: 09/21/2014 11:33 PM »
Yes, but are his papers publicly available and if so where ?

Sorry, didn't mean to sound picky.

OK. So there's a good chance I still have the '64 Sciama here somewhere, at least.

That would be a paper that I haven't mentioned, nor know of.
Sometimes I just flat out don't get it.

Offline Notsosureofit

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Re: EM Drive Developments
« Reply #879 on: 09/21/2014 11:36 PM »
Interesting, note the 50KHz vs couple Gig.  Capacitive effect of dielectric surface to microwaves, check.

Virtual proton/positron creation is a strong function of photon energy (Hz).

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