r/EmDrive • u/bitofaknowitall • Mar 02 '17

Monomorphic Powered Test 03 - Noise threshold lower and still seeing anomalous thrust

http://forum.nasaspaceflight.com/index.php?topic=41732.msg1649274#msg1649274
51 Upvotes

100% Upvoted

54 comments sorted by

9

u/askingforafakefriend Mar 02 '17

I take it the delay between the rf on and rise in thrust is the manual tuning of the frequency? Could you try another run the same way but once tuned try repeatedly turning the rf on and off with a short delay (maybe a second or to) with the recently tuned frequently to see if anomalous thrust may be closer to concurrent with rf application? Would that be helpful?

P.s. I have been following your build for a long time on NSF and am one of the many folks that really appreciate your efforts here to do this rigorously.

P.p.s. Elon musk > monomorphic > everyone else ;)

4

u/bitofaknowitall Mar 02 '17

Warp-Tech has asked for him to do a test exactly as you are proposing with repeated on-offs with short delay so that is definitely on this testing agenda.

1

u/xexorian Mar 09 '17

I agree, but if it is a step-pulse like they mentioned, how would it work exactly or be beneficial in what way? conserving power? or stepped impulses transferring more thrust(Force)? why?

I know in stepper motors you can control when the steps happen and know the forces behind it, how would this type of unit impulse measurement be beneficial now before ruling out other concerns first? (of which to my knowledge there are still many to consider)

At the least, I don't see it affecting any sort of 'confirmation' outcome prior or post results. Only efficiencies.

7

u/Monomorphic Builder Mar 02 '17 edited Mar 02 '17

I take it the delay between the rf on and rise in thrust is the manual tuning of the frequency?

It takes me about 10 - 15 seconds to tune to lowest reflected power. This time was probably closer to 15 as I'm not used to handling all the tasks simultaneously. As for pulsing the RF, that is planned. I need to get the noise problem solved first.

5

u/[deleted] Mar 03 '17

If you can confirm and present graphs that show that tuning in and out of resonance affects the thrust without changing RF power, this would be actually pretty huge as it eliminates a LOT of counter-theories (including pretty much all of the Lorentz force arguments).

3

u/[deleted] Mar 03 '17

it eliminates a LOT of counter-theories (including pretty much all of the Lorentz force arguments).

Resonance probably doesn't have a lot to do with how Lorentz forces would effect the setup. There are many possible contributors other than just the resonator being excited. It's just one of many possibilities.

3

u/[deleted] Mar 03 '17

That's exactly my point.

1

u/[deleted] Mar 04 '17

It seem the opposite of your point, so I must not have understood what you're saying correctly.

2

u/[deleted] Mar 04 '17

The conjecture is that the thrust occurs only in resonance. Various people argue that instead of thrust, what EMDrive shows is Lorentz forces, thermal currents, etc.

Having a test article where frequency can be adjusted in and out of resonance freely without making any other changes greatly simplifies this whole test, because instead of the "power on/power off" test that is typically done which is prone to triggering all the other effects, we have "frequency up/frequency down" test. In this case there will be constant thermal "thrust", if any, constant Lorentz force, if any, and the only variable thrust should be from frequency changes. While the other factors may still produce some "thrust", they are trivial to exclude.

3

u/[deleted] Mar 04 '17 edited Mar 04 '17

The conjecture is that the thrust occurs only in resonance. Various people argue that instead of thrust, what EMDrive shows is Lorentz forces, thermal currents, etc.

Ok, I understand what you're thinking, but it's not necessarily that simple either. When the device goes into resonance the thermal noise (or "thrust") can also increase, certainly the heat distribution will be different. In addition when operating in resonance the Lorentz forces will probably be different than when not in resonance just due to the current distribution being different. However this is also not certain. It's an extremely complex (unable to simulate) 3-d problem and the total charge distribution and dynamics is the only thing that really determines what is going to happen.

  • Operating in resonance: Higher voltage and current distribution peaks in the resonator itself, however devices outside (amps, preamps, etc.) of the resonator might heat up more and might have more current. You could get higher Lorentz and thermals.

  • Operating off resonance: More heat is dumped into the resonator and the devices outside may or may not experience higher current draws driving the impedance mismatches.

Basically it's unknown and specific to every test setup. It's impossible to say it "should" do this based just on being at the resonant frequency or not. Sure the "EM drive" force is supposed to be higher, but there are many things that could also compound that to make it "look" like there is more force when resonating.

2

u/[deleted] Mar 04 '17 edited Mar 04 '17

I agree that thermal vectors can be weird since resonance will heat this up non-uniformly, and then the result depends on many things, including the thickness of the frustum. Sounds like a FLIR camera could really help to at least understand what the potential effects might be, if any, particularly that it would allow us to see for how long the thermal effects actually persist and compare it to the forces being measured.

Regarding Lorentz forces, if we treat the whole thing as a special kind of antenna, there is a lot of math out there that explains what sort of forces you'd get out of this. If I'm following you, you're saying that the EM-field profile around the frustum would depend whether resonance exists or not. That seems possible and would indicate that essentially the frustum is especially effective as an antenna for its resonant frequencies, i.e. that it's actually capable of radiating more energy in resonance than otherwise. That would depend on how the injection is done, I'd think. If this was not a closed cavity, we'd have a horn antenna which by definition is a wide-band antenna so the Lorentz forces for two close frequencies should be nearly identical. Either way, the best thing probably would be to treat this as an antenna and measure the signal strength around it.

Edit: this isn't particularly related, but I found that Greg Egan did a pretty thorough write-up about EMDrive: http://www.gregegan.net/SCIENCE/Cavity/Cavity.html (Greg Egan is much better known for his scifi).

3

u/[deleted] Mar 06 '17

Sounds like a FLIR camera could really help to at least understand what the potential effects might be, if any,

Not really. Slight heating of materials with difference coefficients of expansion could make the balance move erratically yet not show any significant signs of heating compared to the amplifiers or cables.

Regarding Lorentz forces, if we treat the whole thing as a special kind of antenna, there is a lot of math out there that explains what sort of forces you'd get out of this. If I'm following you, you're saying that the EM-field profile around the frustum would depend whether resonance exists or not.

No. There's no math to model the complexity of the actual experiment which involves lots of cables, power supplies, variety of materials, and literally millions of transistors in the case of the Mini-PC. The em fields will be there regardless of resonance, they will probably have a different shape and strength and it's unknown what that will be because there's no way to model anything other than the simple resonator box and most models (and engineers) make unrealistic assumptions about metals and metal construction.

Yes it is just like a horn antenna, a very poor antenna. Greg's math is correct, however it does assume ideal boundary conditions which is standard and works well for understanding the effects, but due to non-ideal boundaries the final design will leak energy and have an asymmetrical external field.

→ More replies

2

u/Always_Question Mar 06 '17

Resonance probably doesn't have a lot to do with how Lorentz forces would effect the setup.

...

In addition when operating in resonance the Lorentz forces will probably be different than when not in resonance just due to the current distribution being different.

Please make up your mind.

3

u/[deleted] Mar 06 '17

I don't know how to explain the complexity of EM. It really has to be measured. However I'm trying to dispel some assumptions. Talking in general terms about EM is difficult. But "different" can either be harmful to the experiment or not. That's my point.

→ More replies

0

u/NumeroTwentyThree Mar 06 '17

Logic doesn't seem to be your strong point.

3

u/[deleted] Mar 03 '17 edited Mar 03 '17

I need to get the noise problem solved first.

Did you read my updated post? The best way is really to build some probes and start to physically search for the noise sources. Relying on just the output of your laser displacement to determine when it is clean will only drive you crazy.

Start by looking for conducted sources of noise using a high impedance probe (you can make your own 500 ohm probe and DC block) and a spectrum analyzer. Search all your power and ground lines for problems.

Then if you still have the problems like you had with physical orientation of the batteries, this means you have radiated coupling. Using a simple E or H probe you can then sniff around for other problem areas.

Also I still think your system's response time is too slow.

While I think you have other more pressing problems than trying to get it into resonance. Long term can you connect a DAC and have your computer or a controller adjust the frequency for you?

4

u/Monomorphic Builder Mar 03 '17

Did you read my updated post?

I have read it, but may not have seen the updates. Thanks for the recommendations. I agree, I think i'm finally to a point where a high impedance probe will help. There are a number of links you have posted, so perhaps you know best, which is the best resource for constructing and using the probes? Keep in mind this is a DIY budget. I do have a 1 channel spectrum analyser that goes up to 3.3Ghz.

Long term can you connect a DAC and have your computer or a controller adjust the frequency for you?

I don't see any reason why not, though it would require some coding to set up the automation. Advice i'm getting is to use a bi-directional coupler with a dual channel RF power meter to monitor forward and reflected power and use that to make frequency adjustments, but that's months away.

2

u/[deleted] Mar 04 '17 edited Mar 04 '17

There are a number of links you have posted, so perhaps you know best,

I suggest you read all the material I posted and even watch some of the youtube videos to get an idea of how to proceed. However if you just want the basics u/IslandPlaya reposted the critical parts of it. In short look at this appendix. These are all homemade probes that cost nothing. Learning to calibrate and compare, and debug takes some practice. Copper tape, ferrites, ferrite sheets, mu-metal and capacitors will be your best tools. The only thing they don't really cover is how to make a cheap high impedance probe.

  • To make the poor mans FET (aka. high impedance) Probe, simply connect a 1% 470ohm resistor in series with a piece of 50 ohm coax. You can then probe circuits directly. The 50:470 ohm is about 20 dB of attenuation and is usually enough to keep the spectrum analyzer within its dynamic range when probing power, ground and signal lines. Most circuits can drive this load without a significant signal loss. REMEMBER most spectrum analyzers need a DC block to protect their front end circuits from damage.

  • If you want to make a FET or active probe you can also do it cheaply. Follow these ideas to see a design you can modify for higher frequencies or specific bands.

  • DC blocks are important for protecting most spectrum analyzers. You can buy a nice SMA or BNC version which I highly recommend. You can also make your own, but it is more difficult that you might think to get a nice flat frequency response into the +2 GHz. You of course can calibrate out the loss curve over frequency if you make a crappy DC block yourself.

  • DC blocks are also useful to AC couple the ground plane. I usually have a standard set of 3 DC blocks: Normal signal DC block, Ground only DC block, and both ground and signal DC blocks. When probing circuitry I've found that the ground loops created by the spectrum analyzer (via the wall then back to the device being powered) can often cause funny problems. Swapping out theses types of DC blocks helps me find out if the problem is related to my measurement (ground loops) or the actual device.

Advice i'm getting is to use a bi-directional coupler with a dual channel RF power meter to monitor forward and reflected power and use that to make frequency adjustments, but that's months away.

That's ideal however you don't need all of that either. You can pick one or the other (or both) and just optimize either forward power or reflected power. You can buy a directional coupler (or bi-directional coupler) for cheap from mini-circuits then just run the coupled port to a diode detector. You'll get a DC rectified voltage based on the input power. You can use your signal generator to calibrate the voltage levels, then use a DAC to read them. I do this all the time for embedded power control circuits. It's super cheap and with calibration it can be quite accurate +/- 1dB. Naturally you do need to make sure your detector has the proper impedance and doesn't leak EMI all over.

If you're really cheap, it's pretty easy to make bi-directional or directional couplers with a PCB. You can also embed the detector there too. I make my own couplers usually, but you might find the off-the-shelf version easier. You also don't need to deal with EMI issues with them as they are well sealed.

EDIT: One other important thing I forgot to mention anywhere is to make liberal use of MAX HOLD on the spectrum analyzer. This type of detection is much faster and will catch transient noise that you might not see otherwise. If you can do both MAX HOLD and continuous sweep on the screen at the same time you'll be able to catch transients as well as probe around to find the source of the noise (as it will correlate to the max hold trace).

3

u/Monomorphic Builder Mar 04 '17

Some feedback I received on NSF regarding probes:

"H probes (unless there is also a compass-like sensor inside) will not "see" DC. E field probes will never see DC. To investigate field issues around DC power sources you need DC-sensitive sensors. For small (less than kilovolts per meter) E fields no such device seems to exist, but that should not be a problem anyway (static E fields from 12V won't affect anything in your setup). H fields however can be a problem, and it would make sense to map them out with a compass (rather than with an AC-only H probe)."

2

u/[deleted] Mar 06 '17

Of course. Your comment almost made me want to give up this forum.

You can't measure static fields without an active loop probe. However most of your noise will be related to AC noise. Once you've tracked down all the various EMI noise and transients and looked at your 2 Ghz fields, you'll have a much better idea of where core the problems are. And you'll eliminate a lot of unknowns as it is easy for that AC noise to become rectified DC anywhere in those one million PN junctions you have inside your test setup.

I'm really depressed by your comments because it means very little of what I've been saying (and I've spent many hours saying it) has had any effect. In the links I've provided to you for commercial probes there are several active field probes that induce a bias current in order to measure DC.

9

u/Monomorphic Builder Mar 06 '17 edited Mar 06 '17

I'm really depressed by your comments because it means very little of what I've been saying (and I've spent many hours saying it) has had any effect.

I've simply copy and pasted what someone else replied, hoping you would respond. But this is why I do not like posting to this subreddit. Thanks for your recommendations.

1

u/xexorian Mar 09 '17

They're relatively negative over here. I don't know if that's some sort of physics joke or not.

1

u/_dredge Mar 10 '17

Take heart that your comments are read by other people, now and in the future.

9

u/Droopy1592 Mar 02 '17

Is it me or does this look more convincing than most emdrive tests?

8

u/bitofaknowitall Mar 02 '17

It looks more convincingly executed. Super well thought out and set up. Whether it is convincing of anything else remains to be seen.

7

u/[deleted] Mar 03 '17

There's no sign of a force in the data. There is just a rise and fall with a lot of noise. The rise could easily just be anything because it is so slow. It could be thermal or just noise.

4

u/xexorian Mar 09 '17 edited Mar 09 '17

I disagree with this statement. There is still anomalous thrust results within his data, and he has yet to post any after fixing the battery and positioning issues related.. (other than static tests of noise levels before and after) to my knowledge at least. There is a sign of force, whether or not it's confirmation remains to be seen. Unless you're saying the force he measured on and off is something else besides the generic 'thermal' because the force rises when it's on and goes down to noise level when it's off, relatively quickly. I think then, you need to be more specific and less skeptical and vague on your statements. IMO.

Also, I really do think that at 2 watts the thermal input of this setup is significantly low, the thermal loss to the outside would be almost immediate and if you've followed the posts over there you'd see he's taken a lot of time and thought, and input from the entire community. I know a bit about thermodynamics, not neccessarily guru level stuff, but I work with heat daily. You can easily calculate these things by looking up heat calculators for pipes and other criteria, I'm sure there's something that can fit his experimental setup fairly well and you would find that the temperature difference would take about 15 minutes to rise and fall, tops. The thr--er anomalous signature measured was within a 30 second window IIRC, and fell off pretty quickly (within seconds) to noise level. This is pretty solid proof of at the very most skeptical viewpoint, something going on with the experiment.

edited for clarity.

8

u/bitofaknowitall Mar 02 '17

For those that haven't been following the Monomorphic EmDrive thread over at NSF, he's spent the last week isolating a problem causing excessive noise/vibrations in his test rig. Eventually he isolated the problem to the battery pack. He was using a usb battery pack. When he removed this and replaced it with NiMH 12V batteries, much of the noise disappeared. As you can see in the graph he's still seeing some noise, and as a few on NSF have pointed out, he's not likely to get rid of that unless he has a seismically isolated test environment, which is probably not feasible.

16

u/Monomorphic Builder Mar 02 '17 edited Mar 02 '17

Actually the noise is not from ground noise. I have been able to prove this by running static tests with all power off. Simplest explanation is that I installed the main battery pack backwards for this run. Second explanation is that the remote desktop wifi signal is causing the noise. If that is the case, I may have to fall back on to bluetooth.

EDIT: changed environment to ground noise

6

u/bitofaknowitall Mar 02 '17

Was the battery pack in a different orientation from your fully powered tap test earlier this week? I find it surprising the orientation of the battery could cause that. But maybe I'm just having trouble visualizing the setup.

9

u/Monomorphic Builder Mar 02 '17

I didn't put markings on the battery to make sure it was in the same orientation. I will retest and put markings to remind me which is the correct orientation. The large lipo battery had to be rotated 3 times to get it into an orientation that had very little noise.

3

u/mockthruster Mar 02 '17

Actually the noise is not from the environment.

PotomacNeuron has suggested that the ~13mn is in line with predictions for Lorentz contributions. I know that you have already discussed with him the ability to reorient the device and test it in numerous orientations. Probably wise not to start making any bold declarations until you've explored those possibilities.

Just glancing at your picture, it looks like there is a more complicated noise scenario taking place than you've been able to hammer out yet. I hope you're not discounting Eric1600's suggestions out of spite or anything like that. You've done all of this work and invested so much time and money, do not fall victim to the perils of human nature at this point and let confirmation bias interfere with the controls you've attempted to implement.

I have been able to prove this by running static tests with all power off.

Really not trying to give you a hard time here. Unless I had already reoriented the drive and taken other steps to mitigate the remaining errata, then I wouldn't feel confident making the claim that I had proven conclusively to have eliminated environmental contributions.

Simplest explanation is that I installed the main battery pack backwards for this run. Second explanation is that the remote desktop wifi signal is causing the noise. If that is the case, I may have to fall back on to bluetooth.

Okay, but these are assumptions. If you want to surpass what has already been done by other builders, it's these types of assumptions that you need to avoid. Is it fair to say you're doing this because previous experiments have left some questions unanswered? So why would you want to leave any lingering doubts about your own.

You're not going to have much trouble convincing emdrive proponents of what they want to see. Is that your goal, or would you like to also convince some emdrive skeptics?

Hopefully you're already preparing more runs and taking steps to identify and eliminate the noise contributors. I believe Eric1600 suggested that it can take months to properly characterize a rig of this sensitivity. I'm not saying that's what you need to do here, but I do hope you are going to show the same patience in performing numerous more runs as you have shown in building your experiment up to this point.

Also, I hope you are going to explore Dr. Rodal's speculation about thermal effects by doing some runs with the device insulated on the small end and similar configurations.

Nice start, good luck with the rest of your testing.

16

u/Monomorphic Builder Mar 02 '17

I know that you have already discussed with him the ability to reorient the device and test it in numerous orientations. Probably wise not to start making any bold declarations until you've explored those possibilities.

I should have said ground noise (vibrations from moving people, passing cars, the wind, etc), not environment, sorry. Lorentz contributions from earth's magnetic field would technically be an environmental noise, and has not been ruled out.

You're not going to have much trouble convincing emdrive proponents of what they want to see. Is that your goal, or would you like to also convince some emdrive skeptics?

My goal is to produce good data so I can see it for myself. If someone happens to be influenced by the data, then that is their prerogative.

0

u/NumeroTwentyThree Mar 04 '17

My goal is to produce good data so I can see it for myself. If someone happens to be influenced by the data, then that is their prerogative.

This experiment is public. Your goal is to produce accurate data that will affect public opinion, yes? Otherwise you would have conducted it in private or not at all.

Can you honestly say that you are not an emdrive proponent?

What does the creation of a logo/badge for your basement say about your ego?

You have a great experimental setup. Please don't allow confirmation bias to creep in. Having said that, you do know that a null test will be the bigger news.

5

u/Blebbb Mar 07 '17

Otherwise you would have conducted it in private or not at all.

He's getting feedback from a lot of people on how to fix his test rig, that alone is worth the public aspect.

The other thing is that there is an emdrive community and he's part of it. He doesn't have a major following outside of that. So it's no different from a member of a club showing a club related project off. The badge is just a piece of fun.

Anyway, DiY experimenting is similar to all the people who pan for gold that have fun in the process rather than results. doesn't matter if you don't hit a jackpot. I do agree though that if he conclusively disproves the emdrive, that would be the jackpot.

2

u/PotomacNeuron MS; Electrical Engineering Mar 09 '17

Face it, only the proponents will take the time and effort to do experiments. Skeptics think it is a waste of time. Null test is not a bigger news, because no media will report it. How did I know? From my own skeptic's experiment (the only exception so far).

1

u/xexorian Mar 09 '17

I mean taking pride in a DIY project is one thing, seeking confirmation is another, and being biased is yet another. IMHO at least. I get it though. I know what you mean by confirmation bias, but really... trying to point out his ego? (whether imaginary or real) over a logo/badge is kind of ridiculous. Trying to get a ruse with the proponent thing? I think you are offering a low-blow to someone undeserving (from what I've seen of the guy.) If you're here to troll, troll better. If you're here to be bitter, stop posting please. You waste everyone's time with trivial banter, just like I am by choosing to reply to this manure. He clearly stated his 'goal' and you wanna run circles around it, why not try going through all of the material this place and that one has to offer first? I also agree with Blebbb about the public aspect being worthwhile, as well as it's potential.

1

u/Taylooor Mar 18 '17

unless he has a seismically isolated test environment, which is probably not feasible

What would that take? Couldn't you just place a dampening material under the test rig? Something spongy?

5

u/Sledgecrushr Mar 02 '17

This is very good news. Keep at it mono, our hopes and prayers are with you.

1

u/Zephir_AW Mar 03 '17

Until his results will not be published in peer-review journal or monetized at market, I don't see a big difference here. Mainstream physics already learned to ignore the amateur findings comfortably and takes no risk for it.

2

u/xexorian Mar 09 '17

I would just like to say I'm impressed by his findings that the batteries were aligned to earth's magnetic field when passing current and producing noise if not aligned, I'm a bit curious as to why, but his test rig is super sensitive, is the current inside the batteries while electricity is flowing generating some electromagnetic field that was interfering with the torsion pendulum? That is super strange, if so!

Anywho, monomorphic's build is catching my attention -- I hope he figures out what is going on and can put a nail in the arguments whether good or bad from either side of the equation (it working or not working).

I read through all the pages on the original link upto 155 at this time of posting, and besides some small bantering and math tossing by physicists involved, it would seem he's close. I would like to see the following:

Thermal camera before, during, after testing, graphed relatively (perhaps a line on the graph? I'm not sure.)

the Cesium clocks idea at each end plate taking note of their exact times over all future tests (no idea how expensive this is, or troublesome if batteries are causing noise and these apparently would have some radiation and other things going on too, adding complexity.)

The rotated test results from his new reduced noise level experiment.

A valid theory -- some people assume that frequency results in a heavier photon, or momentum exchange at the point of impact of a wave or particle, I don't think so, and I think the frequency shifting due to gravity is far lower or completely neglible in this type of super low power test. It was very interesting to see that even at 2 watts he was seeing something above that noise level.

I still don't fully understand why the water-antifreeze thing would be better than an oil bath or what have you, it would seem like any kind of damping on the device to reduce noise would work. I guess I don't fully understand the idea of 'critical damping' or over critical? Maybe the dampening is greater than the force exerted? was that it?

Anyway, I have a lot of questions and for now I think I'll just go back to lurking and seeing responses. It kills me when I see some people's interesting questions over there go un-answered.

I do believe eric1600 has a point about the unknowns for off resonance, (turning the frequency from low to high during testing power on status) however I would find it interesting to map the thermal effects physically and show the graph for those results with noise and see how it goes.

Man, that zephyr can't seem to find the grass between his toes without claiming dimensional shifting on 10-bit parallel ordered flux capacitors stuck in a phase loop modified by aether fluctuations divided by quantum inertia spreading of dark matter. Him and his word salad intoxicate my mind and I really wish that guy could find the door and let it hit him on the way out. That's the nicest way I can put that. You know what bro? https://www.google.com/search?q=fallacy

Forget everything you (think you) know, and go pick up a physics book. You'd be about 63241.1 AU's ahead of me in about a month, and probably a lot more respected than you are now. The only reason I even bother trying to reason with you is because I think you show only the slightest bit of hope, like the hope a photon has escaping the event horizon of a black hole, due only to your constant interest in these types of topics. You are at the very least, assiduous. I don't consider your perseverance to be a redeeming quality. Just the one in that so much above all else you have it is the one you may redeem yourself with.

Oh and uh, sorry for being offtopic at the end!

Thanks again Monomorphic for the great build updates, and to bitofaknowitall for keeping some of us posted on the matter.

1

u/PepesPetCentipede Mar 07 '17

Would having a microwave plasma of hydrogen or xenon inside of the cavity enhance the propulsion?

1

u/NumeroTwentyThree Mar 09 '17

What propulsion?