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#360
by
Star One
on 06 Sep, 2016 10:23
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After the announcement of Dr. Rodal, I have modified my draft explaining NASA's results. The idea is that the theory to be used is a Brans-Dicke instead that a pure general relativity, inside the cavity. The question of what theory really describes our universe is widely open as the Brans-Dicke theory exactly recovers general relativity in all the known tests. But the former allows for a varying Newton constant as seems to be seen in NASA experiments.
If this would be confirmed, it would appear a breakthrough in our knowledge as it would seem that the Brans-Dicke theory is preferred to general relativity even if both theories coincide for all practical purposes.
The draft is here enclosed. It is my paper appeared on arxiv with added a new section before conclusions about Brans-Dicke theory. The computation shows that, just inside the cavity, the electromagnetic field can change the Newton constant because of its energy density. Outside the cavity, the ordinary Newton constant is recovered.
The new version of the paper appeared today on arxiv at
http://arxiv.org/abs/1505.06917
Here I get a general equation for the gravitational constant in the Brans-Dicke model determined by the square of the energy density of the e.m. field inside the cavity. As already said, the gravitational constant, in this case, is modified just inside the volume of the cavity making the effect markedly larger than expected from Einstein gravity. In such conditions, the device does not appear reactionless, as claimed by somebody, but just use gravity.
Brans-Dicke model is a serious contender to Einstein's general relativity since '60 when was formulated. Presently, cosmological tests constrain it but does not rule it out at all.
I looked this theory up on Wikipedia and it was quite hard to follow for a layperson such as myself how it differs from Einstein's theory and why it isn't regarded as applicable to reality?
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#361
by
Flyby
on 06 Sep, 2016 10:33
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StrongGR,
Although i really tried to understand what you did, i must admit the math is just beyond my understanding.
To give you an idea, the first time I ever heard about tensors was here on NSforum. And self study doesn't get me far enough that i can fully grasp whet you did..
But...
I noticed something: between (72) and (73) you give an example with real numbers, using a frequency of 210ghz for a frustrum 100mm high, r1=25mm and r2=100mm to ensure the correct resonance mode.
I do recall a post of Dr. Rodal about the observation that lowering the frequency and making the frustum bigger would generate more force.
As I do not fully understand what you did in developing your ideas, could you have a look into dr Rodal's idea by using real numbers?
It would be nice to know if the notion of "bigger is better" is also supported by your elaborated theory, as it would help to orient future experimental research.
I'll try to dig up dr. Rodal's post, it was outside this topic, but EMdrive related, but cant find it for the moment..
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#362
by
Star One
on 06 Sep, 2016 10:40
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StrongGR,
Although i really tried to understand what you did, i must admit the math is just beyond my understanding.
To give you an idea, the first time I ever heard about tensors was here on NSforum. And self study doesn't get you far enough that i can fully grasp whet you did..
But...
I noticed something: between (72) and (73) you give an example with real numbers, using a frequency of 210ghz for a frustrum 100mm high, r1=25mm and r2=100mm to ensure the correct resonance mode.
I do recall a post of Dr. Rodal about the observation that lowering the frequency and making the frustum bigger would generate more force.
As I do not fully understand what you did in developing your ideas, could you have a look into dr Rodal's idea by using real numbers?
It would be nice to know if the notion of "bigger is better" is also supported by your elaborated theory, as it would help to orient future experimental research.
I'll try to dig up dr. Rodal's post, it was outside this topic, but EMdrive related, but cant find it for the moment..
Is this theory related to the idea that Gravity is different at the local scale in the universe than to the far scale, which is an alternative to Dark Matter theory?
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#363
by
Flyby
on 06 Sep, 2016 11:22
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No, I dont think it was dark matter related. I recall a post of dr.Rodal where he made the observation, through formula's, that Q increased with bigger frustum. As it is a consensus that obtained force is related to Q, it would mean bigger resonating frustums generate bigger forces (on condition the effect is real, ofc)
added:
I think I found the topic :
http://forum.nasaspaceflight.com/index.php?topic=39214.msg1474347#msg1474347from his post (colored for emphasis):
Therefore one concludes that the force per input Power (for all three theories: McCulloch, Shawyer and Notsosureofit) scales like the square root of any geometrical dimension, for constant resistivity and magnetic permeability of the interior wall of the cavity and for constant geometrical ratios, constant medium properties μr,εr, and for the same mode shape m,n,p.
If confirmed, it indicates that research should not be searched in miniaturization, but just in the opposite direction.
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#364
by
Star One
on 06 Sep, 2016 11:38
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In that case if you attached a number of increasingly large EM drives to a test rig wouldn't that make things a whole lot easier to detect and measure?
Is it financial limitations that EW are using such a small device?
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#365
by
TheTraveller
on 06 Sep, 2016 11:39
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No, I dont think it was dark matter related. I recall a post of dr.Rodal where he made the observation, through formula's, that Q increased with bigger frustum. As it is a consensus that obtained force is related to Q, it would mean bigger resonating frustums generate bigger forces (on condition the effect is real, ofc)
added:
I think I found the topic :
http://forum.nasaspaceflight.com/index.php?topic=39214.msg1474347#msg1474347
from his post (colored for emphasis):
Therefore one concludes that the force per input Power (for all three theories: McCulloch, Shawyer and Notsosureofit) scales like the square root of any geometrical dimension, for constant resistivity and magnetic permeability of the interior wall of the cavity and for constant geometrical ratios, constant medium properties μr,εr, and for the same mode shape m,n,p.
If confirmed, it indicates that research should not be searched in miniaturization, but just in the opposite direction.
Seems Cannae are following that approach in their Space Tug, that is to achieve greater area, Q and thrust to design in lower freq. Where lower thrust is OK, then to use higher freq, which results in smaller cavities, which use less volume.
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#366
by
Flyby
on 06 Sep, 2016 12:09
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In that case if you attached a number of increasingly large EM drives to a test rig wouldn't that make things a whole lot easier to detect and measure?
Is it financial limitations that EW are using such a small device?
I suppose the main problem is to find the right generator, so that physical dimensions match with the frequency, in order to obtain the required resonance mode.
The reason to why most DIY frustums are around 20-25cm long, is due to the easy availability of commercial magnetrons that have that ±2.4ghz range.
I have no idea if any cheap Rf generators are available in, fe, the sub 1ghz range?
Construction of a larger frustum maybe be a bit more tedious, but not really problematic, from a technical point of view.
For the moment, it is still a pure intellectual challenge so see if all these theories end up with the same conclusion, that bigger is better...
But if the EMdrive effect is indeed confirmed by the Eagleworks papers, better more conclusive evidence and experiment repeatability will be required.
Larger sized frustum operating with lower frequency might then be a better path to proceed, no?
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#367
by
flux_capacitor
on 06 Sep, 2016 12:42
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I recall a post of dr.Rodal where he made the observation, through formula's, that Q increased with bigger frustum. As it is a consensus that obtained force is related to Q, it would mean bigger resonating frustums generate bigger forces (on condition the effect is real, ofc)
added:
I think I found the topic :
http://forum.nasaspaceflight.com/index.php?topic=39214.msg1474347#msg1474347
from his post (colored for emphasis):
Therefore one concludes that the force per input Power (for all three theories: McCulloch, Shawyer and Notsosureofit) scales like the square root of any geometrical dimension, for constant resistivity and magnetic permeability of the interior wall of the cavity and for constant geometrical ratios, constant medium properties μr,εr, and for the same mode shape m,n,p.
If confirmed, it indicates that research should not be searched in miniaturization, but just in the opposite direction.
Not only the
Q and the generated force should increase, but bigger frustums would also allow an easier control over tuning the distance between end plates, controlling their deformation, as well as better radiative cooling.
Financial requirements appart, only from a state-of-the-art (not DIY) engineering point of view, do you guys know how much large could a frustum be built? The size of a fridge? A church bell? A room? Even bigger?
What about the availability of the required RF generators and the associated frequencies? Are RF wavelengths way outside of the domain of microwaves allowed for a big RF cavity? (in a nutshell:
f < 1 GHz and λ > 30cm)
EDIT: basically I have the same concern as Star One and Flyby in their post before mine.
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#368
by
Star One
on 06 Sep, 2016 12:50
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Also if you scale up the drive if there is evidence of other effects such as gravitational couldn't this be raised to a dangerous level? I mean can we even theorise the effects of large EM drives?
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#369
by
StrongGR
on 06 Sep, 2016 13:08
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...
I looked this theory up on Wikipedia and it was quite hard to follow for a layperson such as myself how it differs from Einstein's theory and why it isn't regarded as applicable to reality?
The idea in Brans-Dicke theory is to add a scalar field (something that has as a value just numbers over all space and time) to standard general relativity. To do that, one assumes that the Newton constant is not really a constant but exactly that scalar field. Anything that has energy couples to gravity, so such a scalar field has an effect back on gravity and vice versa.
This theory is considered a contender to Einstein's theory as it recovers all the tests the general relativity and it could be used to see how far is our universe from Einstein's theory by giving a measurement of the parameters that make the difference between these two theories.
So, on cosmological and planetary scales, one gets that these theories are identical for all practical purposes provided a parameter (omega) is taken large enough.
What makes the difference for a resonant cavity is that you get a significant amount of energy well localized and tests of the two theories in this case are not known. It could be that Brans-Dicke theory performs better in this case supporting the conclusions by NASA on their measurements (remember that we have to see their paper yet).
I hope this help. I can expand if you need it.
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#370
by
krio
on 06 Sep, 2016 13:15
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I recall a post of dr.Rodal where he made the observation, through formula's, that Q increased with bigger frustum. As it is a consensus that obtained force is related to Q, it would mean bigger resonating frustums generate bigger forces (on condition the effect is real, ofc)
added:
I think I found the topic :
http://forum.nasaspaceflight.com/index.php?topic=39214.msg1474347#msg1474347
from his post (colored for emphasis):
Therefore one concludes that the force per input Power (for all three theories: McCulloch, Shawyer and Notsosureofit) scales like the square root of any geometrical dimension, for constant resistivity and magnetic permeability of the interior wall of the cavity and for constant geometrical ratios, constant medium properties μr,εr, and for the same mode shape m,n,p.
If confirmed, it indicates that research should not be searched in miniaturization, but just in the opposite direction.
Not only the Q and the generated force should increase, but bigger frustums would also allow an easier control over tuning the distance between end plates, controlling their deformation, as well as better radiative cooling.
Financial requirements appart, only from a technical point of view, do you guys know how much large could a frustum be built? The size of a fridge? A church bell? A room? Even bigger?
What about the availability of the required RF generators and the associated frequencies? Are RF wavelength way outside of the domain of microwaves allowed for a big RF cavity? (in a nutshell: f < 1 GHz and λ > 30cm)
The problem is also in power output for available RF generators at different frequencies and price of superconductors if you are going to go gen2 at some point. I think there's a confusion in objectives here. Scalability is a long-term engineering task which will be solved one way or another, what is more crucial right now IMHO is to prove that it can produce significant forces and do it as cheaply as possible for others to easily reproduce, write peer reviewed papers about and post youtube videos. That's why I'm asking questions about pulse magnetrons that are used in radars. Those go from $1000 to around $5000 apiece if sourced from the right places.
See here for a general idea:
http://www.radartutorial.eu/08.transmitters/Radar%20Transmitter.en.html
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#371
by
StrongGR
on 06 Sep, 2016 13:37
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StrongGR,
Although i really tried to understand what you did, i must admit the math is just beyond my understanding.
To give you an idea, the first time I ever heard about tensors was here on NSforum. And self study doesn't get me far enough that i can fully grasp whet you did..
But...
I noticed something: between (72) and (73) you give an example with real numbers, using a frequency of 210ghz for a frustrum 100mm high, r1=25mm and r2=100mm to ensure the correct resonance mode.
I do recall a post of Dr. Rodal about the observation that lowering the frequency and making the frustum bigger would generate more force.
As I do not fully understand what you did in developing your ideas, could you have a look into dr Rodal's idea by using real numbers?
It would be nice to know if the notion of "bigger is better" is also supported by your elaborated theory, as it would help to orient future experimental research.
I'll try to dig up dr. Rodal's post, it was outside this topic, but EMdrive related, but cant find it for the moment..
With the first version of the paper, I made a Maple worksheet available with the computations. It evaluated the frequency of the mode and from it it yielded a value of the expected thrust. We agreed with Dr. Rodal that the numbers were way too small with respect to the measured ones (if ever confirmed). This made the paper interesting but not directly applicable to the case. If you like, I can provide the Maple worksheet for you to play with.
This new version fits the bill and should yield values of the thrust in agreement with those NASA has found. For the new version, I have not yet done numerical work. This is somewhat more complex as I have to solve numerically an integral equation. Work for the near future.
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#372
by
StrongGR
on 06 Sep, 2016 13:41
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...
Is this theory related to the idea that Gravity is different at the local scale in the universe than to the far scale, which is an alternative to Dark Matter theory?
Not exactly so. You should imagine a theory where the Newton constant G, the one entering into the well-known equation -Gm
1m
2/r
2, varying from point to point. It was invented before any idea of dark matter and so, was not aimed for it.
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#373
by
PNeilson
on 06 Sep, 2016 13:44
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Marco
As the cavity fills up with photons - what happens to the relative permittivity and permeability in the cavity?
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#374
by
StrongGR
on 06 Sep, 2016 13:57
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Marco
As the cavity fills up with photons - what happens to the relative permittivity and permeability in the cavity?
As far as I can tell, these are constants depending on the material put inside the cavity.
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#375
by
Star One
on 06 Sep, 2016 14:06
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Does the EM drive then distort gravity within the cavity and/or outside it as part of the 'exhaust'? And scaled up sufficiently would this in any way be visually apparent?
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#376
by
StrongGR
on 06 Sep, 2016 14:14
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Does the EM drive then distort gravity within the cavity and/or outside it as part of the 'exhaust'? And scaled up sufficiently would this in any way be visually apparent?
Just inside the cavity where the e.m. energy resides. I think that the effect of the exhaust is really tiny to be seen in some way. The smart thing to do is to shot a laser beam through the cavity in a interferometric experiment. EW just did this. It is ongoing work yet.
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#377
by
Star One
on 06 Sep, 2016 14:37
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Does the EM drive then distort gravity within the cavity and/or outside it as part of the 'exhaust'? And scaled up sufficiently would this in any way be visually apparent?
Just inside the cavity where the e.m. energy resides. I think that the effect of the exhaust is really tiny to be seen in some way. The smart thing to do is to shot a laser beam through the cavity in a interferometric experiment. EW just did this. It is ongoing work yet.
This hopefully will be covered in the AIAA paper then?
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#378
by
StrongGR
on 06 Sep, 2016 14:45
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Does the EM drive then distort gravity within the cavity and/or outside it as part of the 'exhaust'? And scaled up sufficiently would this in any way be visually apparent?
Just inside the cavity where the e.m. energy resides. I think that the effect of the exhaust is really tiny to be seen in some way. The smart thing to do is to shot a laser beam through the cavity in a interferometric experiment. EW just did this. It is ongoing work yet.
This hopefully will be covered in the AIAA paper then?
No, indeed. As far as I know, Dr. White was asked to remove any physical explanation in the paper to appear and publish it on a physics journal. I am not involved in EW activities.
Also, the interferometry studies are ongoing work yet and so, nothing will be said about.
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#379
by
Star One
on 06 Sep, 2016 15:11
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Does the EM drive then distort gravity within the cavity and/or outside it as part of the 'exhaust'? And scaled up sufficiently would this in any way be visually apparent?
Just inside the cavity where the e.m. energy resides. I think that the effect of the exhaust is really tiny to be seen in some way. The smart thing to do is to shot a laser beam through the cavity in a interferometric experiment. EW just did this. It is ongoing work yet.
This hopefully will be covered in the AIAA paper then?
No, indeed. As far as I know, Dr. White was asked to remove any physical explanation in the paper to appear and publish it on a physics journal. I am not involved in EW activities.
Also, the interferometry studies are ongoing work yet and so, nothing will be said about.
Thank you. It's a shame the two things have been decoupled.