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#2980 by Mulletron on 01 Feb, 2018 00:59
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SSI to begin releasing videos of the 2017 Advanced Propulsion Workshop
http://ssi.org/advanced-propulsion-workshop-2017/QuoteLast November Space Studies Institute NASA Innovative Advanced Concepts (NIAC) Team Principal Investigator Dr. Heidi Fearn and Team Consultant Dr. James Woodward invited a group of friends and colleagues to discuss updates in engineering and testing of Propellant-less Propulsion, The “Woodward Effect,” The Machian Principle and other advanced physics and propulsion engineering topics.
Greg Meholic of The Aerospace Corporation, a presenter at the 2016 Estes Park Breakthrough Propulsion Workshop, offered an excellent space for this gathering in the Sally Ride Board Room at The Aerospace Corporation’s El Segundo, California headquarters.
The Space Studies Institute recorded the three day event and we are proud to begin releasing the full-length videos of the presentations starting this week on the SSI YouTube Channel
https://www.youtube.com/c/SSISpaceStudiesInstitute
There were a few papers about the EM Drive presented at this workshop...
For example, this one by Prof. Martin Tajmar that was just posted a few minutes ago:
Very good presentation by Dr. Tajmar. I'm working through all of the other videos. Thanks for bringing these to our attention Dr. Rodal. I wish the NRL would report. In my opinion below, I believe that the lessons learned from the "copper can" versions of the EMdrive have been learned, and they've had their day, and it's time to apply what we've learned from the EMdrive more generally and to greater effect by adding together the effect of countless millions of smaller cavities. We've discussed microcavities in previous threads, and more recently I brought up the idea I found in a work of fiction, which served to confirm my bias.
https://imgur.com/gallery/aGJN3 -
#2981 by dustinthewind on 01 Feb, 2018 02:43
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Capacitive distance sensors are state of the art but i think less useful in such pendulum experiment because of the (distant dependent!) additional force applied by charged capacitor plates.
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Edit3: Nevermind the striked through should not work. I am not sure there is a way to make the plates as equally repulsive as they are attractive.
Perhaps put one capacitive distance sensor on each side, one tending to rotate the torsion wire clockwise and one anti-clockwise.
If the force from each is constant, you are done - at worst the torsion wire will just settle off-centre if the forces are different. If the forces are non-constant with distance, to first order you probably just change the effective stiffness of the torsion wire a little if the change in force is linear with displacement on each side.
Thanks. I think it would change the expected behavior of the pendulum unless the forces are reduced to being insignificant. If the capacitor is kept at constant voltage then the force varies something like the inverse of distance squared. Other issues are that if your using an AC signal to measure capacitance there are some repulsive forces via the changing magnetic field. Another issue is for a pendulum one of the capacitor plates doesn't just come closer but slightly changes in angle.
The laser method seems inherently better at measuring small changes in angle "if" you want to enhance an already existing pendulum. I guess the torsion pendulums are already quite sensitive and one would have to determine if they were enhancing it beyond what is needed, or if it is needed.
Osculating a torsion pendulum to enhance amplitude of deflection may be more than enough if one needed to enhance detection.
A torsion pendulum plus osculation plus angled precision mirrors may be over kill.
Probably the most important is eliminating unwanted measurements such as thermal effects and magnetic interference. That was my primary reason for suggesting double enclosing a pendulum in a free to rotate ferrous box, which is enclosed in a non-rotating ferrous box. The non rotating ferrous box shunts external magnetic fields around the device. The internal ferrous box shunts internal magnetic fields from the pendulum back to the pendulum. Ideally the pendulum is then free to osculate with out regards to interference.
Enclosing the device in an airtight insulated bubble may help eliminate thrust from uneven heating but limits heat dissipation. May contribute to buoyancy which may not be a problem with a torsion pendulum.
The contact-less power transfer peter suggested may help if not using batteries.
I was considering was how to eliminate vibrations from a vibrating MET (mach effect thruster) with the laser method. The laser method is probably overkill and not good for vibrations but had the neat idea of using the pezio sensors to active damp viberations. If a pendulum isn't enough, pulsing thrust at the resonant frequency of the pendulum may be.
I think some have a laser mounted on the pendulum and let it deflect over a distance and for "small angle" 2*pi*r*theta/360=dx .
Interferometry is another I think so maybe not overkill in that light.
It's exciting to see their plans in the video for a free rotating system in vacuum. I guess that's better than storing energy in osculations with damping. -
#2982 by Peter Lauwer on 01 Feb, 2018 09:51
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SSI to begin releasing videos of the 2017 Advanced Propulsion Workshop
http://ssi.org/advanced-propulsion-workshop-2017/QuoteLast November Space Studies Institute NASA Innovative Advanced Concepts (NIAC) Team Principal Investigator Dr. Heidi Fearn and Team Consultant Dr. James Woodward invited a group of friends and colleagues to discuss updates in engineering and testing of Propellant-less Propulsion, The “Woodward Effect,” The Machian Principle and other advanced physics and propulsion engineering topics.
Greg Meholic of The Aerospace Corporation, a presenter at the 2016 Estes Park Breakthrough Propulsion Workshop, offered an excellent space for this gathering in the Sally Ride Board Room at The Aerospace Corporation’s El Segundo, California headquarters.
The Space Studies Institute recorded the three day event and we are proud to begin releasing the full-length videos of the presentations starting this week on the SSI YouTube Channel
https://www.youtube.com/c/SSISpaceStudiesInstitute
There were a few papers about the EM Drive presented at this workshop...
For example, this one by Prof. Martin Tajmar that was just posted a few minutes ago:
I only had time to browse through the first part of Tajmar's presentation. At first glance, it doesn't sound very positive for the existence of an "EmDrive effect".
What I understand from my brief views:
- They measured forces of a few micronewton/watt with the frustum at normal orientation (0 degrees)
- The force reversed when rotating the frustum by 180 degrees
So far so good. But
- They also measured these forces when putting the frustum upright (90 degrees rotation)
Which sounds rather suspect: Probably heat effect or Lorentz forces. And
- They measured with a 40 dB attenuator before the frustum input. And still measured the same forces.
Again: probably Lorentz forces or heat effect (but not from the frustum, therefore not a heat effect which would depend on the orientation of the frustum).
It remains strange then, considering all this, that the forces reversed when rotating the frustum by 180 degrees.
Yes, I have to study Tajmar's presentation more carefully.
Peter -
#2983 by RERT on 01 Feb, 2018 10:38
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I only had time to browse through the first part of Tajmar's presentation. At first glance, it doesn't sound very positive for the existence of an "EmDrive effect".
What I understand from my brief views:
- They measured forces of a few micronewton/watt with the frustum at normal orientation (0 degrees)
- The force reversed when rotating the frustum by 180 degrees
So far so good. But
- They also measured these forces when putting the frustum upright (90 degrees rotation)
Which sounds rather suspect: Probably heat effect or Lorentz forces. And
- They measured with a 40 dB attenuator before the frustum input. And still measured the same forces.
Again: probably Lorentz forces or heat effect (but not from the frustum, therefore not a heat effect which would depend on the orientation of the frustum).
It remains strange then, considering all this, that the forces reversed when rotating the frustum by 180 degrees.
Yes, I have to study Tajmar's presentation more carefully.
Peter
Agreed, very pessimistic. Your last point seems only a small ray of hope. I hope he doesn't give up before implementing the mu-metal shielding and Helmholtz coils, which could be definitive. They seem to have a fabulous measurement setup and should find what the thrust is, even if it is essentially zero. -
#2984 by Peter Lauwer on 01 Feb, 2018 13:08
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Agreed, very pessimistic. Your last point seems only a small ray of hope.
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Or one must assume that the frustum under test generates a force with a direction of 45 degrees (between the axis and the vertical).
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#2985 by dustinthewind on 01 Feb, 2018 13:40
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I only had time to browse through the first part of Tajmar's presentation. At first glance, it doesn't sound very positive for the existence of an "EmDrive effect".
What I understand from my brief views:
- They measured forces of a few micronewton/watt with the frustum at normal orientation (0 degrees)
- The force reversed when rotating the frustum by 180 degrees
So far so good. But
- They also measured these forces when putting the frustum upright (90 degrees rotation)
Which sounds rather suspect: Probably heat effect or Lorentz forces. And
- They measured with a 40 dB attenuator before the frustum input. And still measured the same forces.
Again: probably Lorentz forces or heat effect (but not from the frustum, therefore not a heat effect which would depend on the orientation of the frustum).
It remains strange then, considering all this, that the forces reversed when rotating the frustum by 180 degrees.
Yes, I have to study Tajmar's presentation more carefully.
Peter
Agreed, very pessimistic. Your last point seems only a small ray of hope. I hope he doesn't give up before implementing the mu-metal shielding and Helmholtz coils, which could be definitive. They seem to have a fabulous measurement setup and should find what the thrust is, even if it is essentially zero.
I think they have a lot more to test. Testing on a dummy load instead, or maybe operation of a null mode "if we knew what that was". More than one cavity to test. Dielectrics. Different modes of operation. I would be curious the mode they did test and the apparent stretching of the wavelength. Thermal images of excitation matching predicted currents. I think they are only getting started. Even after all testing a definitive negative result is better than inconclusive. It's exciting they have more than one propellant-less option to test such as MET's.
After the video there was also a moving mirror device based on the dynamic casimir force. I pondered if the optimal displacement of the mirror could be related to the optimal displacement of the MET's but its a little different in that they can just shut the mirror off. Still might work though. Pondered if the moving mirror could possibly be related to an advancing front of quasi particles or advancing holes. Not sure I know enough about it. -
#2986 by Augmentor on 01 Feb, 2018 15:22
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Dynamic Casimir effect has not been excluded yet.
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#2987 by WarpTech on 01 Feb, 2018 15:51
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Agreed, very pessimistic. Your last point seems only a small ray of hope.
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Or one must assume that the frustum under test generates a force with a direction of 45 degrees (between the axis and the vertical).
I think it has to do with feeding the frustum from the side and not from the concentric axis. The antenna + coaxial cable will recoil when the field is emitted by the antenna. Since the feed is on the side... It would be nice if we knew which side the input was on when that test was done, but he didn't show it or mention it.
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#2988 by Monomorphic on 01 Feb, 2018 17:23
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The Navy Research Lab's presentation has been posted:
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#2989 by tchernik on 01 Feb, 2018 19:04
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The Navy Research Lab's presentation has been posted:
This looks like the kind of experiment needed to close the debate of the existence of the Emdrive.
If this one and Dr. Tajmar's experiments find nothing, the debate is over for me. If there's still something... I don't dare speculate.
A negative result may be disappointing for most people following this, but let's remember that knowing the truth is way better than not.
Also and regardless of the outcome, it leaves a legacy of public awareness of what it takes to prove similar proposals and ideas. -
#2990 by oyzw on 02 Feb, 2018 00:02
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The Navy Research Lab's presentation has been posted:
Hello ！ Can you tell me the conclusion of the us naval laboratory? -
#2991 by RotoSequence on 02 Feb, 2018 07:14
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The Navy Research Lab's presentation has been posted:
Hello ！ Can you tell me the conclusion of the us naval laboratory?
The video discusses how they plan to conduct the experiment. There are no results to report yet. -
#2992 by flux_capacitor on 02 Feb, 2018 09:02
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I only had time to browse through the first part of Tajmar's presentation. At first glance, it doesn't sound very positive for the existence of an "EmDrive effect".
What I understand from my brief views:
- They measured forces of a few micronewton/watt with the frustum at normal orientation (0 degrees)
- The force reversed when rotating the frustum by 180 degrees
So far so good. But
- They also measured these forces when putting the frustum upright (90 degrees rotation)
Which sounds rather suspect: Probably heat effect or Lorentz forces. And
- They measured with a 40 dB attenuator before the frustum input. And still measured the same forces.
Again: probably Lorentz forces or heat effect (but not from the frustum, therefore not a heat effect which would depend on the orientation of the frustum).
It remains strange then, considering all this, that the forces reversed when rotating the frustum by 180 degrees.
Yes, I have to study Tajmar's presentation more carefully.
Peter
Agreed, very pessimistic. Your last point seems only a small ray of hope. I hope he doesn't give up before implementing the mu-metal shielding and Helmholtz coils, which could be definitive. They seem to have a fabulous measurement setup and should find what the thrust is, even if it is essentially zero.
Jim Woodward builds Mach Effect Thrusters aka MEGA drives himself (well, with the help of other people, as it's a teamwork) at CSUF, then ships these test articles directly to researchers anywhere in the world, who investigate their behavior on their own balance rig, trying to replicate Woodward's data and better characterize these devices. Martin Tajmar has one or several of these stacks for testing at TU Dresden.
Why in the world nobody asks Roger Shawyer to send them an old EmDrive design (copper 1st gen) to test on their own setup? Why everyone tries to reinvent the wheel without even bothering to ask Shawyer for a working (and according to him, very efficient, with several hundreds of mN/kW) thruster, exactly like Woodward does?
Sonny White didn't even bother to ask Shawyer for one of his thrusters nor his basic design principles, so Paul March had to handmade a frustum at home in his own living room for Eagleworks, apparently similar but having in fact fundamental differences departing from canonical EmDrives (especially regarding Shawyer's design factor and small end "cut-off rule" as well as the use of dielectrics). Tajmar at least asked for Shawyer's advice for his first inefficient mini design out of resonance, with an abysmal Q factor and a giant hole on one side, although we do not know exactly at what point of the development, nor how much Shawyer gave recommendations.
Why every lab (Eagleworks, NWPU, TU Dresden, NRL…) tries to replicate Shawyer's EmDrive design by approximately rebuilding a frustum, instead of asking Shawyer to test a thruster he has already made, is beyond me.
Only Boeing acknowledged to have done so ten years ago, but since their test results are still classified, this is pointless. -
#2993 by Kenjee on 02 Feb, 2018 11:30
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#2994 by francesco nicoli on 02 Feb, 2018 12:00
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I only had time to browse through the first part of Tajmar's presentation. At first glance, it doesn't sound very positive for the existence of an "EmDrive effect".
What I understand from my brief views:
- They measured forces of a few micronewton/watt with the frustum at normal orientation (0 degrees)
- The force reversed when rotating the frustum by 180 degrees
So far so good. But
- They also measured these forces when putting the frustum upright (90 degrees rotation)
Which sounds rather suspect: Probably heat effect or Lorentz forces. And
- They measured with a 40 dB attenuator before the frustum input. And still measured the same forces.
Again: probably Lorentz forces or heat effect (but not from the frustum, therefore not a heat effect which would depend on the orientation of the frustum).
It remains strange then, considering all this, that the forces reversed when rotating the frustum by 180 degrees.
Yes, I have to study Tajmar's presentation more carefully.
Peter
Agreed, very pessimistic. Your last point seems only a small ray of hope. I hope he doesn't give up before implementing the mu-metal shielding and Helmholtz coils, which could be definitive. They seem to have a fabulous measurement setup and should find what the thrust is, even if it is essentially zero.
Jim Woodward builds Mach Effect Thrusters aka MEGA drives himself (well, with the help of other people, as it's a teamwork) at CSUF, then ships these test articles directly to researchers anywhere in the world, who investigate their behavior on their own balance rig, trying to replicate Woodward's data and better characterize these devices. Martin Tajmar has one or several of these stacks for testing at TU Dresden.
Why in the world nobody asks Roger Shawyer to send them an old EmDrive design (copper 1st gen) to test on their own setup? Why everyone tries to reinvent the wheel without even bothering to ask Shawyer for a working (and according to him, very efficient, with several hundreds of mN/kW) thruster, exactly like Woodward does?
Sonny White didn't even bother to ask Shawyer for one of his thrusters nor his basic design principles, so Paul March had to handmade a frustum at home in his own living room for Eagleworks, apparently similar but having in fact fundamental differences departing from canonical EmDrives (especially regarding Shawyer's design factor and small end "cut-off rule" as well as the use of dielectrics). Tajmar at least asked for Shawyer's advice for his first inefficient mini design out of resonance, with an abysmal Q factor and a giant hole on one side, although we do not know exactly at what point of the development, nor how much Shawyer gave recommendations.
Why every lab (Eagleworks, NWPU, TU Dresden, NRL…) tries to replicate Shawyer's EmDrive design by approximately rebuilding a frustum, instead of asking Shawyer to test a thruster he has already made, is beyond me.
Only Boeing acknowledged to have done so ten years ago, but since their test results are still classified, this is pointless.
1. afaik, Shawyer never wanted to share details. And for the "working prototype" he would have asked substantial money (as he did with Boeing?) and his own supervision.
2. Are you sure Boeing results are "classified"? afaik, they simply terminated the contract saying they are not interested. Different thing.
3. I am pretty sure that they would be very glad if Shawyer sent him a test item for trials and validation. I am pretty sure it won't happen. -
#2995 by flux_capacitor on 02 Feb, 2018 13:10
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1. afaik, Shawyer never wanted to share details. And for the "working prototype" he would have asked substantial money (as he did with Boeing?) and his own supervision.
So what? Doesn't it cost money also to build oneself a proper, dimensionally stable or tuning frustum with a high Q factor, from scratch and without years of refining such design? What is the purpose of these labs: to build the cheapest test article with copper foils themselves, which may not work; to make a particular lab or researcher look good in the media; or to finally measure thrust levels clearly above the noise? One should decide. This is not a hobby.
Let's remember Shawyer's first prototype would have produced a thrust of 16mN @850W in 2002, and the subsequent Demonstrator Engine shown on websites is claimed to have produced an effective measured thrust of ~120 mN @400W (specific thrust of ~300 mN/kW) in 2006. This is not the same playground than anything that has been tested elsewhere since.
I may add that the Flight thruster Boeing acquired, that you mentioned, was at that time some very "advanced" model at SPR Ltd, in 2010. Eight years laters, advanced projects have moved to cryogenic and superconducting designs according to Shawyer, yet only an access to the prior demonstrator or even the now fifteen years old "archaic" first prototype would be enough. Not even the Flight Thruster. Because a thrust efficiency of hundreds of millinewtons per kilowatt of input RF power would be enough to settle the case without keeping asking about how much convection currents play a role, or thermal expansion, or Lorentz forces with or without DC ground loops, or any unknown bizarre lateral force component, etc.Quote2. Are you sure Boeing results are "classified"? afaik, they simply terminated the contract saying they are not interested. Different thing.
Some turn of phrase indeed. But my point is: Boeing tested the thing, but never released the data, period. If a research center, a magazine, an organization, whatever… (not just one ordinary man in the street) ask them to analyse the data, they should give it, as the results are said to be negative and they claim they are "no longer pursuing this avenue". But they won't (at least I think so, but did anyone ever tried?*). Why? I don't know, but existing information that nobody can access is the same thing for me as classified information. Pretty much the same definition. Give it the term "secrete" or "sensitive" instead, if you think that the term "classified" refers too much to some governmental thingy. But secrete or sensitive information unavailable to anyone about something that does not work and is no longer studied is weird, to say the least.Quote3. I am pretty sure that they would be very glad if Shawyer sent him a test item for trials and validation. I am pretty sure it won't happen.
Maybe, but as I said above for myself, thinking (being "pretty sure") is not knowing for a fact. This is a preconception. So why people in that research circle do not even try to ask him?
This would settle a bit more the degree of desire of Roger Shawyer to shed some light and give some credit about his technology, without compromising his commercial NDA contracts about "more advanced designs".
* At least a year ago I tried myself to do something concrete, i.e. to encourage (as a non-US citizen but closer to circles who are able, know and already did it) people to make an FOIA request in order to access Boeing's data of SPR Ltd flight thruster testing. Nobody seemed interested. -
#2996 by PotomacNeuron on 02 Feb, 2018 14:16
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I looked at the "Deep Space" wiki page at https://en.wikipedia.org/wiki/Deep_Space_1 , and it said (color added by me),
"The NASA Solar Technology Application Readiness (NSTAR) electrostatic ion thruster, developed at NASA Glenn, achieves a specific impulse of 1000–3000 seconds. This is an order of magnitude higher than traditional space propulsion methods, resulting in a mass savings of approximately half. This leads to much cheaper launch vehicles. Although the engine produces just 92 millinewtons (0.33 ozf) thrust at maximal power (2,100 W on DS1), the craft achieved high speeds because ion engines thrust continuously for long periods."
Now look at Shawyer's thruster, as you said, "120 mN @400W in 2006". If it is true, there is no reason for him to hide it for 12 years and counting, especially with the fact that he is not young any more. The only reasonable conclusion is he had not achieved even 1/10 of the claimed thrust.
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#2997 by graybeardsyseng on 03 Feb, 2018 15:29
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I looked at the "Deep Space" wiki page at https://en.wikipedia.org/wiki/Deep_Space_1 , and it said (color added by me),
"The NASA Solar Technology Application Readiness (NSTAR) electrostatic ion thruster, developed at NASA Glenn, achieves a specific impulse of 1000–3000 seconds. This is an order of magnitude higher than traditional space propulsion methods, resulting in a mass savings of approximately half. This leads to much cheaper launch vehicles. Although the engine produces just 92 millinewtons (0.33 ozf) thrust at maximal power (2,100 W on DS1), the craft achieved high speeds because ion engines thrust continuously for long periods."
Now look at Shawyer's thruster, as you said, "120 mN @400W in 2006". If it is true, there is no reason for him to hide it for 12 years and counting, especially with the fact that he is not young any more. The only reasonable conclusion is he had not achieved even 1/10 of the claimed thrust.
I suspect you are correct. While I'm not quite ready to say that is the "ONLY" reasonable conclusion - I can conjure other scenarios which "MIGHT" be reasonable - I fear that your analysis is most probably correct. I fail to understand how Shawyer's decades long approach to dribbling bits and pieces of frequently outdated information - often partial data for a specific design - so as to virtually prevent anyone from duplicating his work - can be anything but some for of disinformation campaign. Perhaps it is motivated by some commercial advantage viewpoint, perhaps from some attempt to protect classified information, but I suspect it is primarily self aggrandizement and self promotion.
graybeardsyseng
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#2998 by Mulletron on 03 Feb, 2018 21:42
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I think a good idea is to move away from microwave cavities and instead to counterpropagate (when I say counterpropagate, I mean launch laser light through each end of the bundle in order to create a partial standing wave, vice a standing wave; unequal amplitude so you need dissipation, or unequal wavelength to create beats, but you still need dissipation so that energy doesn't remain constant) light modes through photonic crystal fiber bundles. The cavities in photonic crystal fibers are an analogue to the EMdrive cavity, only obviously shorter wavelength and more of them. I'm thinking in lines of curl G=- 2/c dBg/dt (from Mashhoon and Bini et al) and my reasoning is trying to accelerate (really abruptly change the acceleration of) the invariant mass of counterpropagating photons to achieve a very weak effect (gravitational induction) and to place in linear superposition many tiny effects (unmeasurable acceleration with curl) into a cumulative large macroscopic effect.
I'm pretty serious about this, I decided to buy a thousand .3mm ID capillary tubes after some research into figuring out what I needed to engineer, and fill them with diatoms (a natural photonic crystal) to try out thanks to some inspiration from a complete work of fiction I read (yeah I know, it's funny how that works, it actually really bothers me) that popped out to me from the noise because I learned about the physics they were talking about from studying the EMdrive for the past few years. The author sure has a gift for blurring fact and fiction to say the least. I didn't want to talk about it, but I decided that I must be honest with others no matter what. It's weird experiencing something like this and I wonder if it's something others have experienced throughout history, getting ideas from fiction which have their roots in basic research.
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#2999 by Rodal on 03 Feb, 2018 22:45
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... to try out thanks to some inspiration from a complete work of fiction I read (yeah I know, it's funny how that works, it actually really bothers me) ...
You should not let this bother you
! On the contrary, it makes sense that creativity (really new ideas) may be triggered by works of fiction. And many scientists not only read fiction, but actually write fiction !. You are not going to be really creative and break the mold by making small increments on what has been done for decades 
! On the contrary, it makes sense that creativity (really new ideas) may be triggered by works of fiction. And many scientists not only read fiction, but actually write fiction !. You are not going to be really creative and break the mold by making small increments on what has been done for decades