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#2840
by
WarpTech
on 24 Feb, 2017 16:49
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...
Only if the EM-Field generation was off the torsion pendulum beam. It can't "push on itself" to generate thrust.
My Best,
Shell
Yes, agreed of course, but this is true for this effect acting on the aluminum beam as well.
No electronic equipment attached to the aluminum beam can cause the aluminum beam to self-accelerate either 
Whatever is producing the alternating magnetic field has to be external to what is acting on (the aluminum beam or the copper EM Drive) to get it to accelerate.
But we're not seeing the beam "self-accelerate". We're seeing it oscillate, probably in sync with the binary data packets traveling in the USB cable. What is attached to the beam, can make it self-oscillate, if the signal is pulsed.
One time we connected a 208V, 3Ph transformer to a 480V source by mistake. It blew the 3000A utility fuse for the entire building when the core saturated. Even though all the cables, for all 3 phases were in one metal conduit that completely encased the wires. The conduit was attached to the building rafters and when that fuse blew, the entire building shook and rang like a bell from the enormous pulse of current.
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#2841
by
Rodal
on 24 Feb, 2017 16:52
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...
Only if the EM-Field generation was off the torsion pendulum beam. It can't "push on itself" to generate thrust.
My Best,
Shell
Yes, agreed of course, but this is true for this effect acting on the aluminum beam as well.
No electronic equipment attached to the aluminum beam can cause the aluminum beam to self-accelerate either
Whatever is producing the alternating magnetic field has to be external to what is acting on (the aluminum beam or the copper EM Drive) to get it to accelerate.
But we're not seeing the beam "self-accelerate". We're seeing it oscillate, probably in sync with the binary data packets traveling in the USB cable. What is attached to the beam, can make it self-oscillate, if the signal is pulsed.
One time we connected a 208V, 3Ph transformer to a 480V source by mistake. It blew the 3000A utility fuse for the entire building when the core saturated. Even though all the cables, for all 3 phases were in one metal conduit that completely encased the wires. The conduit was attached to the building rafters and when that fuse blew, the entire building shook and rang like a bell from the enormous pulse of current.
Ok, that is called a
vibration, which can be a forced vibration or a self-excited vibration.
Yes, something can be made to vibrate (oscillate) , and it can be self-excited, or parametric.
And to explain the noise, this is quite applicable, thanks.
--------------------------------
By self-accelerate I was referring accelerating
the center of mass..
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#2842
by
jmossman
on 24 Feb, 2017 17:44
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...
Only if the EM-Field generation was off the torsion pendulum beam. It can't "push on itself" to generate thrust.
My Best,
Shell
Yes, agreed of course, but this is true for this effect acting on the aluminum beam as well.
No electronic equipment attached to the aluminum beam can cause the aluminum beam to self-accelerate either
Whatever is producing the alternating magnetic field has to be external to what is acting on (the aluminum beam or the copper EM Drive) to get it to accelerate.
Perhaps the LDS sensors as well? (which will also have time varying EM fields)
Regardless of the precise source/interaction, SeeShell's earlier recommendation of MuMetal shielding sounded like a pretty good mitigation option. 2 regions of copper foil tape, each grounded to their respective battery, with a surrounding MuMetal shield layer between the aluminum beam and the copper foil tape might help. I'd also envision some insulation material between the various layers of shielding.
Another option is to increase the physical distance between the electronics/cables and the aluminum beam. Although MuMetal shielding would still be needed to reduce/attenuate any interaction with the earth's magnetic field.
http://www.ebay.com/itm/MuMetal-Ultraperm-Permalloy-Alloy-Shielding-Sheet-Mu-Metal-Audio-Shield-80-/152045122881
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#2843
by
SeeShells
on 24 Feb, 2017 20:01
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...
Only if the EM-Field generation was off the torsion pendulum beam. It can't "push on itself" to generate thrust.
My Best,
Shell
Yes, agreed of course, but this is true for this effect acting on the aluminum beam as well.
No electronic equipment attached to the aluminum beam can cause the aluminum beam to self-accelerate either
Whatever is producing the alternating magnetic field has to be external to what is acting on (the aluminum beam or the copper EM Drive) to get it to accelerate.
But we're not seeing the beam "self-accelerate". We're seeing it oscillate, probably in sync with the binary data packets traveling in the USB cable. What is attached to the beam, can make it self-oscillate, if the signal is pulsed.
One time we connected a 208V, 3Ph transformer to a 480V source by mistake. It blew the 3000A utility fuse for the entire building when the core saturated. Even though all the cables, for all 3 phases were in one metal conduit that completely encased the wires. The conduit was attached to the building rafters and when that fuse blew, the entire building shook and rang like a bell from the enormous pulse of current.
This would be the most cost effective for Monomorphic to persue IMHO.
Move the electronics to the bottom of the pendulum bar and build a box of Mu-metal for the components.
This keeps any magnetic fields parallel to the top support beam and any other leveraged effect (heat) pushing on the bottom of the beam instead of the sides where they could induce movement.
My Best,
Shell
PS: jmossman has it correct as well.
http://forum.nasaspaceflight.com/index.php?topic=41732.msg1646732#msg1646732
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#2844
by
Monomorphic
on 24 Feb, 2017 21:21
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Perhaps the LDS sensors as well? (which will also have time varying EM fields)
The LDS sensors are not mounted to the torsional pendulum beam, they are mounted to the structure that supports the beam. I do not think their wires are close enough to be of concern.
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#2845
by
Monomorphic
on 24 Feb, 2017 21:44
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This would be the most cost effective for Monomorphic to persue IMHO.
Move the electronics to the bottom of the pendulum bar and build a box of Mu-metal for the components.
This keeps any magnetic fields parallel to the top support beam and any other leveraged effect (heat) pushing on the bottom of the beam instead of the sides where they could induce movement.
Shell,
This is very close to what I have in mind for plan B. My noise floor now is 5-6 uN. If through shortening wires, using ferrites, and other mitigation techniques I can't get that to ~2 uN, then I will probably do something like this.
I've found that it is important that the weight not be distributed evenly along the beam as it becomes less responsive. Think of the torsional pendulum beam as a spinning ballerina who pulls her arms in to speed up the spin. Keep as much as the mass as possible towards the center so the system is more responsive. Like so:
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#2846
by
Rodal
on 24 Feb, 2017 23:18
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Moo Metal ?
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#2847
by
Stormbringer
on 25 Feb, 2017 00:50
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New poster image for OCD is measuring the mass of snow flakes
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#2848
by
SeeShells
on 25 Feb, 2017 03:30
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Moo Metal ?
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#2849
by
SeeShells
on 25 Feb, 2017 03:36
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This would be the most cost effective for Monomorphic to persue IMHO.
Move the electronics to the bottom of the pendulum bar and build a box of Mu-metal for the components.
This keeps any magnetic fields parallel to the top support beam and any other leveraged effect (heat) pushing on the bottom of the beam instead of the sides where they could induce movement.
Shell,
This is very close to what I have in mind for plan B. My noise floor now is 5-6 uN. If through shortening wires, using ferrites, and other mitigation techniques I can't get that to ~2 uN, then I will probably do something like this.
I've found that it is important that the weight not be distributed evenly along the beam as it becomes less responsive. Think of the torsional pendulum beam as a spinning ballerina who pulls her arms in to speed up the spin. Keep as much as the mass as possible towards the center so the system is more responsive. Like so:
You are of course right and if you see my pendulum wire assy. you'll see I set most of the weight in the center also and used fiber carbon arms to reduce it even further.
You're doing one heck of a job Jamie.
My Very Best,
Shell
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#2850
by
sanman
on 25 Feb, 2017 07:06
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Just FYI - since the question was raised on this thread not too long ago - I had inquired with people in the know at the Indian Space Research Organization to ask whether ISRO was investigating the EMdrive concept. I was told that while ISRO is not currently investigating the EMdrive, they would be doing so in the future.
The issue is that EMdrive is about massless propulsion, for which the fundamental physics has not been proven out yet - and meanwhile I guess with ISRO being more application-oriented, they tend to first focus on technologies with a high Technology Readiness Level, which would be of the more mainstream variety.
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#2851
by
FattyLumpkin
on 25 Feb, 2017 07:54
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40 LY for tidally locked? earth 2.0
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#2852
by
sanman
on 25 Feb, 2017 08:42
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40 LY for tidally locked? earth 2.0
Well, even if it's not ideal - it could be an indicator that there are many more such worlds waiting to be discovered, and that sooner or later we'll find something that's a near-perfect analog of our own Earth.
Once we find someplace that's worth going to, based on habitability and on proximity to us, then perhaps it will create a greater push to seek out and develop viable options for travel there, whether it's EMdrive or whatever.
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#2853
by
Stormbringer
on 25 Feb, 2017 15:24
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40 LY for tidally locked? earth 2.0
Well, even if it's not ideal - it could be an indicator that there are many more such worlds waiting to be discovered, and that sooner or later we'll find something that's a near-perfect analog of our own Earth.
Once we find someplace that's worth going to, based on habitability and on proximity to us, then perhaps it will create a greater push to seek out and develop viable options for travel there, whether it's EMdrive or whatever.
The trappist star system has 7, that's right 7, earth mass rocky planets with three of those definitely in the habitability zone and 4 that are either close or possibly in it too given the variability of factors that can make a planet warmer than crude habitability zone guess work would indicate. Tidal locking is not a show stopper providing the planet has an atmosphere and or oceans. Indications are that these planets formed distal to the Trapist star and migrated inward later meaning youthful flaring of the star may not have baked/irradiated these planets during their youth. The distance is not ideal for actual physical voyages from earth but are not so formidable that it could not be done (sending probes or even intrepid generational pioneers) by determined nations with patient long term visions. Certainly at least we could make astronomical instruments that could examine those planets in detail from home and see if anything there is worth the time and effort for actual missions. Red dwarf stars make up the majority of stars in our neighborhood by far than sol type g dwarfs or k dwarfs so it is heartening that from 60 to 90 percent of them (statistical guesses by experts) have earth sized planets to ogle with upcoming telescopes.
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#2854
by
meberbs
on 25 Feb, 2017 15:41
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I'll spare the mods some effort and just mention that discussion of the awesome planetary discovery goes in
its own thread. This thread gets rather long, so its better to keep it focused. Plus there already is a lot of good discussion of the discovery in that other thread.
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#2855
by
Monomorphic
on 25 Feb, 2017 15:52
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Four hours of cutting, soldering, shielding, and heat shrinking later...
I removed quite a bit of extra wire during cable management. Enough that I had to level the torsional pendulum beam again. I don't have any ferrites yet. I want to run tests first to see if they are necessary.
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#2856
by
FattyLumpkin
on 25 Feb, 2017 16:31
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meberbs, you are correct of course about the appropriate thread. The only reason I put the images up is because questions are already arising as to how "we" can get there. This will compound itself even greater over the next three years when TESS begins pumping out it's data. Sorry for the inconvenience. FL
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#2857
by
jmossman
on 25 Feb, 2017 17:09
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Perhaps the LDS sensors as well? (which will also have time varying EM fields)
The LDS sensors are not mounted to the torsional pendulum beam, they are mounted to the structure that supports the beam. I do not think their wires are close enough to be of concern.
I agree that the LDS sensors are unlikely to be inducing fields in the aluminum pendulum beam due to the airgap.
Instead, I was offering a potential external field that could be interacting with the payload electronics attached to the aluminum pendulum beam. Running a power-on test (with payload on but LDS sensors off) would allow one to quantify how much, if any, interaction was with the LDS sensors.
The "vibration" mode, with the cables wiggling, that you are pursuing certainly sounds like a (more) feasible noise source than the (presumably) low magnitude of LDS sensor fields. Adding a spacer between the electronics and the beam might help quantify how much of an "induced field in pendulum beam" was also in play.
I honestly would have expected thermal effects to swamp out the EM effects... but you are trying to measure the weight of snowflakes at ~2-5uN... so maybe the thermal is such a low frequency (ie effectively DC) while the "vibration" of the cables is high enough to oscillate the pendulum? Although a >20 second period of a pendulum is already "DC" relative to EM effects, so I guess we wait and see.
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#2858
by
Rodal
on 25 Feb, 2017 21:09
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...
I honestly would have expected thermal effects to swamp out the EM effects... but you are trying to measure the weight of snowflakes at ~2-5uN... so maybe the thermal is such a low frequency (ie effectively DC) while the "vibration" of the cables is high enough to oscillate the pendulum? Although a >20 second period of a pendulum is already "DC" relative to EM effects, so I guess we wait and see.
Right on,
the period of this torsional pendulum is 48 seconds,
the frequency is 0.02 Hertz,can somebody explain how can such a low frequency be excited by oscillating electromagnetic effects used in Monomorphic's setup?
As a way of comparison,
electrical power in the US is supplied at a frequency of 60 Hertz: that is 60/0.02 =
2880 times higher frequency than the frequency of the noise in Monomorphic's torsional pendulum.
Seems more likely that it would be excited by a series of EM
impulses and bursts of Lorentz force rather than being excited by any steady oscillatory EM frequency.
So whether the source of excitation is mechanical, fluid convection or electromagnetic, in all three cases it seems more likely to be due to impulse excitations rather than
steady oscillation excitation.
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#2859
by
Rodal
on 25 Feb, 2017 22:37
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By the way, Earth's magnetic field is practically static, compared to the frequency of torsional oscillations of Monomorphic's pendulum (0.02 Hertz) .
From what I can gather, the highest frequency of the Earth's magnetic field reversals that one would find in a spectrum, have a period of 10 to 20 years, so nowhere even close to 48 seconds.
So, for Monomorphic's pendulum the Earth's magnetic field would not be introducing any eddy currents on the aluminum beam or the copper of the EM Drive and since the beam made of aluminum and EM Drive made of copper, both of them having relative magnetic permeability extremely close to 1, it should not have a steady magnetic effect either.
Monomorphic's microwave excitation inside the EM Drive is solid state, not provided by a Magnetron.
So how could Monomorphic's setup interact with Earth's magnetic field ?
Only if in the torsional beam there is any attached material with significant relative magnetic permeability...
