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#740 by rfmwguy on 20 Sep, 2016 00:40
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Hello All,
There are those who would say that that an open cone is simply a "nozzle" so I would focus on what exactly is being focused or directed outwardwards. There is someone already experimenting with an open cone, Nassikas from Greece. Believe his design is superconductive magnetic...not following it closely.
(...)
If this sounds too complex and fantastic for you then let me summarize and add this key takeaway: Q may represent resonance, but resonance does not necessarily imply thrust. For thrust to occur, most theories rely on the energy density (read: imbalance) of the electromagnetic fields. The best route to improve thrust then is focusing on internal geometries, especially focusing on photon channeling for the maximum density of the photon clouds. In other words the frustum should not be empty just for the sake of better resonance, as others have noted. -
#741 by dustinthewind on 20 Sep, 2016 00:58
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Yes, I am giving a presentation (not anything I have discussed so far at NSF-EM Drive) on Tuesday, 20 September, during Block 3, 1:30PM-3:10PM, sharing this block with Prof. Heidi Fearn (California State, Fullerton). I will discuss a self-consistent solution, derived from Hoyle-Narlikar theory of gravitation, a computational model and several comparisons with experimental force results conducted in a vacuum chamber. Also experimental impedance spectroscopy results.
Are you presenting Dr. Rodal? If so, do you have a quick summary of what you're covering?
Shell
I hadn't heard of Hoyle-Narlikar gravitation before, so I Wikipedia'd myself up to speed.Quote from: Stephan HawkingOn the Hoyle-Narlikar Theory of Gravitation
It is shown that the direct-particle action-principle from which Hoyle & Narlikar derive their new theory of gravitation not only yields the Einstein field-equations in the 'smooth-fluid' approximation, but also implies that the 'm'-field be given by the sum of half the retarded field and half the advanced field calculated from the world-lines of the particles. This is in effect a boundary condition for the Einstein equations, and it appears that it is incompatible with an expanding universe since the advanced field would be infinite. A possible way of overcoming this difficulty would be to allow the existence of negative mass.
This should be interesting!
I will focus my presentation for space propulsion on an exact solution assuming a) solid material velocities much smaller than the speed of light and b) very small inertial mass fluctuations, and its comparison with experiments.
But addressing your question regarding the paper from Hawking in 1965, the Einstein-de Sitter model (used by Hawking) does not allow for an accelerating expansion. Heidi Fearn has a possible answer to that issue in this paper (pages 9 to 13):
https://www.researchgate.net/publication/269721882_Mach's_Principle_Action_at_a_Distance_and_Cosmology
EDIT: Basically, the expansion of the universe ( Nobel Prize in Physics 2011 https://www.nobelprize.org/nobel_prizes/physics/laureates/2011/advanced-physicsprize2011.pdf ) allows one to define a Rindler cutoff for the advanced waves and so their integral, does not diverge. Of course Hawking back in 1965 did not know the universe was accelerating.... So Hawking was right at the time.
There are other possible answers (besides Hawking's answer regarding negative mass, and H. Fearn's answer), for example an n-dimensional Kaluza-Klein theory like this one
https://www.researchgate.net/publication/278121181_N-dimensional_Kaluza-Klein_universe_in_Hoyle-Narlikar_C-field_cosmology
In any case the present accelerating expansion phase of the universe, including the dark energy hypotheis, is still not satisfactorily explained to the complete satisfaction of the majority of physicists
The paper also mentions the Wheeler Feynman connection with signals propagating backwards in time and the negative energy fields. This reminded me of the thought that the vacuum may be made up of matter and anti-matter superimposed with time running backwards for anti-matter, and it also having anti-mass. With anti-mass running backwards in time, it seems like it would appear to have positive mass, which then allows us to push off it with normal momentum. If the anti-matter/mass/time overlaps with its mirror twin, then maybe it seems the anti-mass may lose its positive mass properties becoming negative mass and canceling the positive mass, cloaking into the vacuum.
Some thoughts on the matter were that if we have polarization waves of matter/anti-matter and anti-matter has reversed time then that might give us an idea why we have the duality of advanced waves along with retarded waves. It might also give us a source of a negative energy C field?
I was thinking, in a cavity, normally the electric and magnetic fields are not highly superimposed over each other. They are out of phase in time and mostly separated in the cavity. However, if large enough electric fields were to cause polarization of the vacuum such that a current developed in the vacuum, and at the same time there was a magnetic field superimposed over the electric field then both charges would experience a force in the same direction. This might serve as a propellant which could absorb momentum and then re-merge to pass through the cavity. Any thoughts?
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#742 by VAXHeadroom on 20 Sep, 2016 02:34
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Not to fear...there is an emdrive hardware expo in the works...will keep people advised once it shapes up more than general chatter. Seems like the organizers will be insisting on proof of a legitimate design/build/test, which is probably a good thing. Not going to be a centauri deams type of thing from what I gather. An interesting year ahead for all of us I suspect...Locale? East Coast.New EmDrive article on conference: http://www.ibtimes.co.uk/emdrive-controversial-space-propulsion-will-be-discussed-by-scientists-actual-conference-1582115
I was in Estes Park yesterday. Stopped by The Stanley and asked if the conference was being held there. Turns out it is being held at the YMCA. Unfortunately I had to fly back today and couldn't change my schedule to attend. Doh!
If you don't already have a venue in mind, I've got a line on a good one near the BWI airport.
-- Emory
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#743 by JonathanD on 20 Sep, 2016 03:59
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New EmDrive article on conference: http://www.ibtimes.co.uk/emdrive-controversial-space-propulsion-will-be-discussed-by-scientists-actual-conference-1582115
Confirmed we will have emdrive tie fighters. Source: random article stock photo
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#744 by Chrochne on 20 Sep, 2016 05:14
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New EmDrive article on conference: http://www.ibtimes.co.uk/emdrive-controversial-space-propulsion-will-be-discussed-by-scientists-actual-conference-1582115
Confirmed we will have emdrive tie fighters. Source: random article stock photo
Well we do not have any picture of the recent EmDrive units as people are keeping them to themselves. So I guess that is the reason for that picture. If you might have any pictures I have connections that can push them through. -
#745 by OnlyMe on 20 Sep, 2016 05:22
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That non-believer on reddit you referred to might be me. I post that post in a hurry and (cherry-) picked some facts, most were from memory, just to prevent the post from being deleted by the modulator. It suffered being not complete as a result.
I'm fine with an incomplete or hurried text/article, if it wasn't for inappropriate use of the word "trend".
That made me react, because it was clearly a biased way of formulating.
It was however the perfect excuse to stand up for neutrality in this bizarre case of a "propellantless engine", so I hold no grunge...
The point is how to weigh all these DIY results : there is a minority of tests that are most certainly negative and there is a majority of "possible positive".
Do the 100% null results count for more then the uncertainty of all the APPARENT positive tests? hard to judge...
"Trend" is about null results are more recent and positive tests are older.
The only trend that can be reliably arrived at from the experiments that information is available from, experimenters building different frustrums, test beds and the using different EM power sources.., is that different frustums, power sources and test beds get different results.
All of the positive results could be artifacts and or systemic error or the real deal...., and all of the null results could be proof of bad designs or that the thrust is some kind of artifact....
We will never know for certain from any of the null result tests. Only when experiments that have returned thrust have been independently repeated with the same EXACT builds, and all systemic and other variables have been ruled out or identified as the source of the thrust, will any of us know anything with any certainty. BTW while Prof. Yang has every right to modify her conclusions, there is nothing about her second experiment and paper that nullifies the first. The two were far different in to many ways to be thought of as anything but different experiments with different builds, and I never saw anything published with enough detail that anyone could reproduce either frustum or experiment. That is the real trouble none of what has been shared about the many builds has shown two builders performing identical experiments.
I want to believe the EMDrive does produce useable thrust. Even small amounts (xxx mN) would be good enough. If that turns out to be the case no matter how it does it, it will require in the least a rethinking of our understanding of some fundamental interpretations of physics that has stood for over three hundred years.
I am skeptical that Gravity (as in Spacetime) is being manipulated, but I would be thrilled if that turned out to be the case. The potential for a concentration of energy, creating a gravitational field, has been in the math for close to a hundred years now. We just don't see gravity where we don't also see mass. So that part of the math remains theoretical.
Personally if there is real thrust (and I believe there is) I expect it will require no more than a far more mundane reinterpretation / understanding of the relationship and importance of conservation of momentum (CoM) and conservation of energy (CoE), with a greater emphasis on the CoE aspect. IOW as long as the energy balances out in the end, one could argue that CoM has not been violated even where the only exhaust is a dissipation of energy.
As long as I am on a rant here.., the idea of unlimited acceleration is almost laughable. There has been a lot of discussion about the Quantum Vacuum (QV), but not a great deal of clear description of just what that means. Still there is a growing consensus that the QV does exist, even where agreement on just what it is, is lacking. In any event, without a warp drive or some sub space engineering, that could take whatever QV model you believe in out of the picture, any object composed of atoms does not appear to be able to exceed something between 20-30% the speed of light before the atoms begin to ionize. (Which would result in the spaceship coming apart.) At least not in our labs or anything we can observe with any degree of certainty.., cosmologically. -
#746 by oyzw on 20 Sep, 2016 06:26
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BTW I have offered my spherical end plate frustum design to EW for their consideration as their next build.
这个位置电场强度低，耦合度低，我都进行过仿真。
It should generate Flight Thruster like performance but at the 2.45GHz their existing Rf system can drive. -
#747 by Chrochne on 20 Sep, 2016 07:09
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https://goo.gl/oUOHsX
YMCA Estes Park Colorado - You can walk right inside the building. Nice google street feature. Something for us that are on another side of the world
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It is very nice place for conference about the EmDrive :-). -
#748 by R.W. Keyes on 20 Sep, 2016 07:35
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I just read the IBTimes article regarding the SSI Estes Park conference which starts today. There's something about it, which I can't put my finger on, that worries me. I worry that too much is going to be said which will disrupt research and give the media sharks more chum.
One of the disadvantages of this forum its its open nature. On the other hand, if it wasn't fairly open I wouldn't likely be able to be here. The Groucho Marx gag, for sure.
I am concerned that I don't see mention of Prof. McCulloch presenting, or even attending. IMHO, his theory is the best explanation of the EMDrive effect. -
#749 by RERT on 20 Sep, 2016 07:46
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I wouldn't take issue with the catalogue of success/fails in DIY testing recently posted, but I don't think all votes are equal.
If EW comes out with an unequivocal yes, given the apparently massive pressure on them not to stoke speculation casually, I think counts for many votes.
Read SPR's accounts for the last decade or so. Shawyer has had a lot of $$$ and many years to test his effect. To maintain it works, either it does or he is somewhere in the crooked/delusional/mistaken spectrum. It will be interesting to see if SPR continues to make money this year.
Cannae have a torsional pendulum operating in a vacuum capable, they say of 0.2 microNewton resolution. They claim to have measured thrust, and have announced plans to put up/find $$$ to launch a cubesat test. Again, they have either seen something, or are crooked/delusional/etc.
Yes, there is Rossi!
But there is a growing collection of powerful votes in favour of the tech actually working. I'd guess that explains the recent positive tone of this forum, and perhaps the timing of the conference. -
#750 by RERT on 20 Sep, 2016 08:03
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There is an article on page 34 of the 20th August issue of the New Scientist on 'the ignorosphere'.
'...below 300km, [the atmosphere] is too thick for satellites to survive the drag forces for more than a few months.'
Cannae's cubesat is targetted at 240km for six months.
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#751 by Mezzenile on 20 Sep, 2016 08:24
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... We just don't see gravity where we don't also see mass.
This is wrong. There are non trivial solutions to the equations of General relativity with no mass present. These solutions without mass are called Calabi-Yau spaces-time, they present curvature and so gravity. -
#752 by Unentitled on 20 Sep, 2016 08:28
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I just read the IBTimes article regarding the SSI Estes Park conference which starts today. There's something about it, which I can't put my finger on, that worries me. I worry that too much is going to be said which will disrupt research and give the media sharks more chum.
One of the disadvantages of this forum its its open nature. On the other hand, if it wasn't fairly open I wouldn't likely be able to be here. The Groucho Marx gag, for sure.
I am concerned that I don't see mention of Prof. McCulloch presenting, or even attending. IMHO, his theory is the best explanation of the EMDrive effect.
While also concerned with the ibtimes method of presentation of forum posts, I, for one, am happy to see some pointed collaboration taking place at the SSI conference regarding the EMdrive and multiple other related/unrelated (it is physics though) theories in a more private or intimate setting.
I believe more may be gained by such interactions, at least to those invested in rigorously investigating the matter at hand. And of course those willing and or lucky enough to attend.
I agree with the chum statement and personally don't agree with the way that article is displaying forum posts in a way disingenuous to the actual forum discussion and adding an unknown narrator's perspective of it. Which may be why I prefer such interest parties have the opportunity to collaborate in a way outside of the realm of news media.
I also wish McCulloch will have a say at this event. If not in person then through video of the event and further discussion that may, hopefully, be shared through this forum. Granted I'm more than happy to see some NSF posters being present!
Apologies for the non-technical interjection. Looking forward to further discussion as I've thoroughly enjoyed what this forum has to offer. -
#753 by Flyby on 20 Sep, 2016 08:34
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I wouldn't take issue with the catalogue of success/fails in DIY testing recently posted, but I don't think all votes are equal.
It was never the intend of the listing to favor either side of the obtained results, but to illustrate the need for caution and not to jump to hasty conclusions.
........
But there is a growing collection of powerful votes in favour of the tech actually working. I'd guess that explains the recent positive tone of this forum, and perhaps the timing of the conference.
The obtained DIY results are not straightforward and as indicated previously , I find it -in its current state- very difficult to attribute a "clear winner side".
So...with what we know today, anyone claiming positive or negative results from the EM drive is jumping the gun.I am concerned that I don't see mention of Prof. McCulloch presenting, or even attending. IMHO, his theory is the best explanation of the EMDrive effect.
I'm not so sure that McCulloh Unruh effect holds the most promise as you say.
Can you elaborate why you have that opinion?
As outsider, I see 2 main paths in theoretical model development : those who relay on a momentum transfer system (Shawyer) and those who look for an alternative way , that has no direct relation with transfer of momentum (from EM wave to the frustum).
The reason for that is simple : there is an apparent (*) conflict with Conservation of Momentum.(CoM)
Those scientist looking for alternative ways (micro-gravity, unruh, QVP, etc) do realize the CoM conflict and are looking for creative ways to get around that elephant in the room.
Those alternatives appear, with today's knowledge, quite exotic and maybe even far fetched. This is also why there is so much hand wavering from traditional oriented scientists.
(*) note that I prefer to use the word "apparent", because I like to leave the question open whether we fully understand momentum transfer. -
#754 by Mezzenile on 20 Sep, 2016 08:40
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There is an article on page 34 of the 20th August issue of the New Scientist on 'the ignorosphere'.
The satellite GOCE has conducted a close to 4 years mission at 250 km altitude (255 -235 km over the full life). This satellite was devoted to make very accurate measurements of the Earth gravity (it was able to easily detect the additional mass of water in Amazonia during rain season). This satellite had an aerodynamic shape to reduce the residual atmosphere drag and was equipped with xenon ionic thruster to offset this drag.
'...below 300km, [the atmosphere] is too thick for satellites to survive the drag forces for more than a few months.'
Cannae's cubesat is targetted at 240km for six months. -
#755 by giulioprisco on 20 Sep, 2016 12:52
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SSI is to be applauded in this approach in sponsoring this veritable mind-meld of Physicists, PhDs, Educators, Engineers and even the highly interested who have a common mindset and goal.
Let us dream.
Shell
YES. Dreaming bold and beautiful dreams is essential to the mental health of individual and societies. And sometime hard and smart work makes those dreams come true. -
#756 by Gilbertdrive on 20 Sep, 2016 13:07
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As long as I am on a rant here.., the idea of unlimited acceleration is almost laughable. There has been a lot of discussion about the Quantum Vacuum (QV), but not a great deal of clear description of just what that means. Still there is a growing consensus that the QV does exist, even where agreement on just what it is, is lacking. In any event, without a warp drive or some sub space engineering, that could take whatever QV model you believe in out of the picture, any object composed of atoms does not appear to be able to exceed something between 20-30% the speed of light before the atoms begin to ionize. (Which would result in the spaceship coming apart.) At least not in our labs or anything we can observe with any degree of certainty.., cosmologically.
Since, in GR, as in Newtonian physics, there is no local difference between uniform motion, and immobility, I do not see why this limit to 20-30% of C.
In it's own referential, the speed of any ship will always be zero.
At the opposite, the most distant galaxies are moving away from us at 90% of C. Also, in the referential of one of them, the earth is moving to 90% of C, and I am still no totally ionized
Since the speed is only relative to a referential (as it was told for Kinetic Energy in thread 7) and since there is no absolute referential in GR, there is no speed limit other than C. There is no ionisation or coming apart. But, of course, micrometeorites become very dangereous, if their speed is high relatively to the ship -
#757 by Rodal on 20 Sep, 2016 13:09
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...I am concerned that I don't see mention of Prof. McCulloch presenting, or even attending. IMHO, his theory is the best explanation of the EMDrive effect.
My understanding is that the organizers were planning to enable a workshop discussion with a few such notable authors in this field (Breakthrough Propulsion), using a video and/or audio connection, due to their remote location. Hopefully this video and/or audio connection will be successfully accomplished, depending on the speed of the Internet connection at the workshop's facility.
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#758 by meberbs on 20 Sep, 2016 13:42
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For the same builds what is important is the same thrust from the same frustum and antenna design for the same RF input properties. For the rest of the setup, the more different the better as long as measurement sensitivity and accuracy is maintained. Otherwise it still could be a systematic error in the measurement. Also specific modifications showing predictable changes in thrust would be useful as well (e.g. a coating to deliberately reduce Q by a factor of 2 also reducing thrust by that factor) Of course that is the second step, after a reliable signal is found to begin with.
We will never know for certain from any of the null result tests. Only when experiments that have returned thrust have been independently repeated with the same EXACT builds, and all systemic and other variables have been ruled out or identified as the source of the thrust, will any of us know anything with any certainty. BTW while Prof. Yang has every right to modify her conclusions, there is nothing about her second experiment and paper that nullifies the first. The two were far different in to many ways to be thought of as anything but different experiments with different builds, and I never saw anything published with enough detail that anyone could reproduce either frustum or experiment. That is the real trouble none of what has been shared about the many builds has shown two builders performing identical experiments.
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Also you must have missed the part in Yang's second paper where she provided an explanation of an error source in the original that either would be the full cause of the result, or at least swamp any real signal making the data from the first experiment useless. While more detail on how she determined this would be helpful, there is no good reason to doubt the conclusion. -
#759 by OnlyMe on 20 Sep, 2016 14:09
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... We just don't see gravity where we don't also see mass.
This is wrong. There are non trivial solutions to the equations of General relativity with no mass present. These solutions without mass are called Calabi-Yau spaces-time, they present curvature and so gravity.
Yes! This is why I mentioned the fact that the potential has been in the math for a very long time. The difficulty is demonstrating the solution experimentally or through some unambiguous or perhaps undebatable natural observation.
With the exception of Dark Matter and even perhaps to some extent Dark Energy, both of which remain unproven theoretical solutions, where do we find any gravitational field that we can say with any certainty originates from anything other than the presence of mass?
While mass IS (in my opinion) a concentration of energy, not all concentrations of energy can currently be described as mass.
In a sense my point was and is, in that comment, that even though GR and for that matter even the Brans-Dicke theory are very successful descriptions of what we do observe of gravitational fields, as has been pointed out, not all solutions and/or predictions have been observed or confirmed.
None of this means that any non-trivial solution that has not been observed is not a real representation of reality. It just means that until it(they) has been observed in nature or recreated in the lab, they remain theoretical predictions.
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