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#60
by
Star One
on 18 Jun, 2018 16:24
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Hope people find this of interest.
Marc Millis on Mach Effect Thruster, EmDrive Testsby PAUL GILSTER on JUNE 18, 2018
Marc Millis spent the summer of 2017 at the Technische Universität Dresden, where he taught a class called Introduction to Interstellar Flight and Propulsion Physics, a course he would also teach at Purdue University last November. The former head of NASA’s Breakthrough Propulsion Physics project and founding architect of the Tau Zero Foundation, Marc participated in the SpaceDrive project run by Martin Tajmar in Dresden, an effort that has been in the news with its laboratory testing of two controversial propulsion concepts: The Mach Effect Thruster and the EmDrive. Marc’s review comments on modeling for the former were almost as long as Tajmar’s draft paper. Described below, the SpaceDrive project is a wider effort that includes more than these two areas — neither the EmD or MET thruster had reached active test phase during the summer he was there — but the ongoing work on both occupies Millis in the essay that follows.
My bolding.
You may have noticed a renewed burst of articles about the EmDrive. What prompted this round of coverage was an interim report, part of the progress on Martin Tajmar’s ‘SpaceDrive’ project to carefully test such claims. Tajmar’s conference paper [citation below] is one of the early steps to check for false-positives. I expect more papers to follow, each progressing to other possibilities. It might take a year or so more before irrefutable results are in. Until then, treat the press stories about certain conclusions as highly suspect.
https://www.centauri-dreams.org/2018/06/18/marc-millis-on-mach-effect-thruster-emdrive-tests/Notice that the Mach Effect thruster is looking to be a very different beast than the EM Drive. I imagine this is a attempted corrective article to some of the poor press reporting.
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#61
by
Monomorphic
on 18 Jun, 2018 21:49
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When trying to confirm resonant modes in the frustum that won't load the cavity, you can either spray paint the exterior of the cavity a flat black then IR camera check the exterior surfaces for temp differentials and/or just use a strip of black vinyl electrical tape along the side wall and across both the small and large OD ends of the frustum as I did at the Eagleworks Lab. However I do understand that if your frustum sidewalls and endcaps are too thick, that the thermal diffusion of the surface current induced joule heating of the copper side walls and endcaps will make the IR camera resonant-mode monitoring challenging at best.
Thanks Paul, I have an IR camera, so I will definitely be trying that method with Oyzw's solid copper spun cavity. For when the cavity is mounted inside the draft enclosure, behind plexiglass windows that do not transmit IR, I am looking at thermochromatic paint. It is available at a variety of color transition temperatures such as 72F, 77F, 82F, 88F, 99F and so on:
https://www.amazon.com/Temperature-Activated-Changing-Thermochromic-changing/dp/B0714F3KZ6?th=1That way I can see the mode shape through the plexiglass windows for a period until the entire cavity heated up beyond the transition temp.
Otherwise, I may need to install a small window of material that is IR transparent. The Flir One I use operates between 8-15um, so I'm looking at Potassium Bromide (KBr) or Sodium Chloride (NaCl) windows. Zinc Selenide (ZnSe) is too costly.
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#62
by
AnalogMan
on 18 Jun, 2018 22:47
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[...]
Otherwise, I may need to install a small window of material that is IR transparent. The Flir One I use operates between 8-15um, so I'm looking at Potassium Bromide (KBr) or Sodium Chloride (NaCl) windows. Zinc Selenide (ZnSe) is too costly.
There are one or two modestly priced IR windows on Ebay that might be suitable - try this
link.
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#63
by
demofsky
on 19 Jun, 2018 02:14
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From my spot in the peanut gallery, thermochromic paint looks like a better option because you can see the thermal patterns for the entire fustrum as a whole rather than one spot inside. I could imagine having to build several fustrums with different window positions to get a more complete picture otherwise.
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#64
by
Tcarey
on 19 Jun, 2018 03:47
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Monomorphic,
I just ran a quick test on Saran Wrap as an IR window. Using a Harbor Freight IR gun measuring the temperature of a burner on a gas stove I measured 276° direct and 235° through a single layer of Saran Wrap.
Since you are looking for relative differences more than absolute temperature this might be a quick and very low cost solution for your IR window. I have no idea what IR frequency range the Harbor Freight gun uses but doing a quick test with your IR camera will tell you if Saran Wrap will work for your requirements.
Just a thought.
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#65
by
OttO
on 19 Jun, 2018 08:22
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Otherwise, I may need to install a small window of material that is IR transparent. The Flir One I use operates between 8-15um, so I'm looking at Potassium Bromide (KBr) or Sodium Chloride (NaCl) windows. Zinc Selenide (ZnSe) is too costly.
You can try to use thin sheet of HDPE (0.5mm) (it is the material for passive IR detector lenses)
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#66
by
Star-Drive
on 19 Jun, 2018 14:25
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When trying to confirm resonant modes in the frustum that won't load the cavity, you can either spray paint the exterior of the cavity a flat black then IR camera check the exterior surfaces for temp differentials and/or just use a strip of black vinyl electrical tape along the side wall and across both the small and large OD ends of the frustum as I did at the Eagleworks Lab. However I do understand that if your frustum sidewalls and endcaps are too thick, that the thermal diffusion of the surface current induced joule heating of the copper side walls and endcaps will make the IR camera resonant-mode monitoring challenging at best.
Thanks Paul, I have an IR camera, so I will definitely be trying that method with Oyzw's solid copper spun cavity. For when the cavity is mounted inside the draft enclosure, behind plexiglass windows that do not transmit IR, I am looking at thermochromatic paint. It is available at a variety of color transition temperatures such as 72F, 77F, 82F, 88F, 99F and so on: https://www.amazon.com/Temperature-Activated-Changing-Thermochromic-changing/dp/B0714F3KZ6?th=1
That way I can see the mode shape through the plexiglass windows for a period until the entire cavity heated up beyond the transition temp.
Otherwise, I may need to install a small window of material that is IR transparent. The Flir One I use operates between 8-15um, so I'm looking at Potassium Bromide (KBr) or Sodium Chloride (NaCl) windows. Zinc Selenide (ZnSe) is too costly.
Jamie:
Thanks much to you and everyone else on this thread for their possible alternative IR transmission windows for these types of experiments, much appreciated.
BTW, you don't have to IR view the resonant cavity in the wind enclosure or vacuum chamber all the time. You can just view it while in the lab and not on the torque pendulum to make sure that the selected drive frequency and tuning configuration is driving the desired resonant mode over the desired RF input power range. And as long as there are no nearby frequency resonant modes that might be inadvertently driven, you can be fairly confident of what mode you are driving while you have the resonant cavity on the thrust balance by just verifying the drive frequency and Smith chart display pattern previously documented.
Best,
Paul M.
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#67
by
Mulletron
on 20 Jun, 2018 01:47
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How many visible wavelength optical cavities do you suppose are in this bag?
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#68
by
spupeng7
on 20 Jun, 2018 06:06
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I clearly stated that the only things provided have just been repeating the "future work" information in the paper, which is not criticism, just an indication that the person saying those things did not read the paper.
I read the paper and watched Tajmar's presentation, thank you very much. 
The criticisms noted are valid even though Tajmar plans on ruling most of them out in future experiments. Some of the items pointed out, such as why they claim to be exciting mode TM212 during their presentation, when that mode is 500Mhz away in simulations, and why they are 15Mhz away from any known mode for those dimensions, AND the fact that they chose not to share their smith chart plot, are serious problems that need to be addressed specifically in the next paper.
We also pointed out that the wiring was sophomoric at best as the twisted pairs were not twisted very well, the main power leads were over a meter long, and the ground loops have not been identified. We also pointed out that the amplifier and most other electrical components rotate with the copper frustum, instead of only the frustum rotating. It is not clear if Tajmar plans on addressing these issues in the future.
Once Tajmar confirms the resonant mode with IR camera, or other means, then that will alleviate most of my concerns. I am glad this is planned and look forward to the results. I know that is one of the last hurdles I am working on before I throw in the towel...
Monomorphic,
I do not like the notion of you throwing in the towel... please run as full a test series on each frustum you have, and record the results in exquisite detail, before you even consider any such thing. You may have taken this further than any other amateur and it would be a crying shame if it were not taken to its conclusion after all the work you have put in.
Remember, all the theory that says this can't work is deeply intimate with paradox, it simply cannot be relied upon to rule out Machian effects completely. Please run this movie to the end because there are many of us holding our breath for your results and some of us are confident that you will not be disappointed in the long run. Your methodology is an inspiration to us so please do not quit till you must.
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#69
by
jankeman
on 20 Jun, 2018 21:45
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EM drives sounds more like a warp drive, basically you open up a wormhole to another place. We don't have the technology to bend time and space to reach a place faster. Look at the proposed alcubierre drive, which would connect the space in front of the drive with space behind the drive, thus reach faster-than-light travel. It has similar capabilities, give the vehicle a FTL travel speed, and that requires 'exotic' matter, which has exotic properties. Maybe in 2 decades, we may research newer space technologies that can allow us to create a wormhole to the whole cosmos
So, I think it's a no for now
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#70
by
LowerAtmosphere
on 21 Jun, 2018 08:19
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EM drives sounds more like a warp drive, basically you open up a wormhole to another place. We don't have the technology to bend time and space to reach a place faster. Look at the proposed alcubierre drive, which would connect the space in front of the drive with space behind the drive, thus reach faster-than-light travel. It has similar capabilities, give the vehicle a FTL travel speed, and that requires 'exotic' matter, which has exotic properties. Maybe in 2 decades, we may research newer space technologies that can allow us to create a wormhole to the whole cosmos
So, I think it's a no for now
Please take the time to read as much of the past 10 threads as possible. The goal of our research is to memorize (try to) and reprocess the contents of emdrive.wiki
UPDATE: It appears emdrive.wiki has been dehosted??? Latest archive:
https://web.archive.org/web/*/emdrive.wiki
If dehosted permanently this would be a huge loss. I know many of us contributed to it.
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#71
by
VAXHeadroom
on 21 Jun, 2018 16:40
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EM drives sounds more like a warp drive, basically you open up a wormhole to another place. We don't have the technology to bend time and space to reach a place faster. Look at the proposed alcubierre drive, which would connect the space in front of the drive with space behind the drive, thus reach faster-than-light travel. It has similar capabilities, give the vehicle a FTL travel speed, and that requires 'exotic' matter, which has exotic properties. Maybe in 2 decades, we may research newer space technologies that can allow us to create a wormhole to the whole cosmos
So, I think it's a no for now
Sorry, but it is none of those things. If you'd like to contribute, you have a lot of catching up to do - I did when I first heard of this concept and it took me the better part of 2 years (part time) to be able to understand the problems and concepts the builders and theorists were talking about.
And given all that, I'm pretty sure the answer is YES, but I'm not sure of the magnitude
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#72
by
X_RaY
on 25 Jun, 2018 18:51
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Testing the miniVNA tiny+ with a 1/4 wave stub antenna.
Phil (TT),
would you like to report on your current activities regarding the KISS engine? The community is still curious!
Jamie (Monomorphic) has delivered and generally confirmed the applicability of mode confirmation as suggested by you (although handling the probe does not seem to be easy).
However, a good discussion could result from the publication of your current experiments.
Are you ready to step out of the shadows with real experimental data?
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#73
by
flux_capacitor
on 25 Jun, 2018 20:52
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Yes, I can't wait for TheTraveller's KISS thruster going round and round! Hope he won't go dark again at the same time the EmDrive has to come out of the shadows. A few breadcrumbs would be welcome, as 2018 had to be a very interesting year.
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#74
by
Monomorphic
on 26 Jun, 2018 10:54
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Yes, I can't wait for TheTraveller's KISS thruster going round and round! Hope he won't go dark again at the same time the EmDrive has to come out of the shadows. A few breadcrumbs would be welcome, as 2018 had to be a very interesting year.
Phil is probably realizing it is not as easy as he thought to form the copper using a plastic flower pot. I remember I had to use a thick metal pipe to get the bends needed and it was still not very easy. I was going to recommend that he fill the flower pot with cement to make it more rigid.
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#75
by
RERT
on 26 Jun, 2018 15:16
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I'm up to browser bookmark 414 in this blog. I really need a criteria to enable me to get on with my life!
If The Traveller can't make this work, nobody can: he does seem to have a hotline to Shawyer, and talks a decent game on RF engineering, though I suppose metalwork skills (as above) etc are not a given.
I will try and make myself quit worrying if there is nothing forthcoming from TT this year, or on another announced schedule.
I would regard a positive result from Monomorphic as equally definitive in the opposite direction.
So no pressure....
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#76
by
VAXHeadroom
on 27 Jun, 2018 14:59
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...
If The Traveller can't make this work, nobody can: ...
So no pressure....
Don't count out Monomorphic and SeeShells!!
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#77
by
LowerAtmosphere
on 27 Jun, 2018 20:45
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Don't take my word for it, but I think a lot more funding for space exploration and travel is inbound. Governmental priorities are not some immutable force. At the very least you have done an immeasurable service for the future of humanity. Physics is dogmatic and physicists split into factions far too easily. Here we proved that even if there is squabbling at least serious work has been accomplished, thus I am hopeful for the future of ALL related research. Our main currency is not in funding or design or even the rational genius of connecting disparate concepts, but in encouraging those who would otherwise eternally dwell in silence to come forward and offer their work and research for peer review. Even if I put my own research on the backburner I still created a mesh rack thruster prototype. Remember: your life is fleeting but your work and deductions transcend time and space.
P.S. Read Asimov and Herbert if you even remotely like this topic. Sometimes the best inspiration is in the imaginative and the fictional, for it is there that one must confront ones own assumptions.
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#78
by
TheTraveller
on 27 Jun, 2018 23:03
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I'm up to browser bookmark 414 in this blog. I really need a criteria to enable me to get on with my life!
If The Traveller can't make this work, nobody can: he does seem to have a hotline to Shawyer, and talks a decent game on RF engineering, though I suppose metalwork skills (as above) etc are not a given.
I will try and make myself quit worrying if there is nothing forthcoming from TT this year, or on another announced schedule.
I would regard a positive result from Monomorphic as equally definitive in the opposite direction.
So no pressure....
Hi Rert,
Still waiting for the Silver Epoxy. Seems the supplier had no stock when I ordered. Don't want to clean the edge and outer surface before I have the epoxy and then have it start to oxidize.
As for forming over the flower pot, some of the hoop ring are installed internally, help in position with hot glue, to make the form much stiffer. Then more hoop rings are used externally to form and hold the copper frustum in place. Have done this before, so know it can be done fairly easily. The hoop rings are the trick.
Between that I have installed new side and back fencing plus rebuilding bedroom furniture for a friends son. So no rest.
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#79
by
zen-in
on 30 Jun, 2018 15:33
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I'm up to browser bookmark 414 in this blog. I really need a criteria to enable me to get on with my life!
If The Traveller can't make this work, nobody can: he does seem to have a hotline to Shawyer, and talks a decent game on RF engineering, though I suppose metalwork skills (as above) etc are not a given.
I will try and make myself quit worrying if there is nothing forthcoming from TT this year, or on another announced schedule.
I would regard a positive result from Monomorphic as equally definitive in the opposite direction.
So no pressure....
Hi Rert,
Still waiting for the Silver Epoxy. Seems the supplier had no stock when I ordered. Don't want to clean the edge and outer surface before I have the epoxy and then have it start to oxidize.
As for forming over the flower pot, some of the hoop ring are installed internally, help in position with hot glue, to make the form much stiffer. Then more hoop rings are used externally to form and hold the copper frustum in place. Have done this before, so know it can be done fairly easily. The hoop rings are the trick.
Between that I have installed new side and back fencing plus rebuilding bedroom furniture for a friends son. So no rest.
You don't have to worry about Copper oxidation. Copper oxidizes very slowly at room temperature, in dry air. Conductive epoxy contains Silver and will produce a contact potential with Copper. Another method you might want to look into is to use Copper rivets.
