by PAUL GILSTER on JUNE 18, 2018Marc 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.
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.
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.
[...]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.
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.
Quote from: Star-Drive on 06/18/2018 02:35 pmWhen 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.
Quote from: meberbs on 06/17/2018 12:09 amI 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...
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.
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 cosmosSo, I think it's a no for now
Testing the miniVNA tiny+ with a 1/4 wave stub antenna.
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.
...If The Traveller can't make this work, nobody can: ...So no pressure....
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....
Quote from: RERT on 06/26/2018 03:16 pmI'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.