Author Topic: EM Drive Developments - related to space flight applications - Thread 5  (Read 941069 times)

Online SeeShells

  • Senior Member
  • *****
  • Posts: 2364
  • Every action there's a reaction we try to grasp.
  • United States
  • Liked: 3089
  • Likes Given: 2660
The perfect experiment does not exist. It is folly to assume you or anyone else can design one.

It's not about the "perfect experiment". It's that there are so many confounding factors that are in the same micro-newton range as the expected positive results.

If you were building a device that could lift itself and 5kg to the ceiling of your workshop, you'd only need a spring scale from your local bait'n'tackle to measure the force being produced at the accuracy required at this level. You wouldn't need a "perfect experiment" that measures every breath of air down to the micro-newton. The only confounding factors (unless there's a tornado in your lab) is whether you are cheating and using magicians' tricks - and that is easily solved by independent replication.

But when the heating of the air around the device can produce uplift larger than the desired effect, when visually undetectable thermal warping of the mechanism (or of the balance) may be sufficient to swamp the readings, when even current running through the power cables produces forces on the same order as those you're measuring, you are playing a vastly different game.

Unless you are capable of going beyond the level of isolation of the Eagleworks tests, you can't really add anything to the field. I mean, it sounds like ridiculous fun and I wish all of you success, but you aren't doing "research".

No matter, research will go on without you and our hope is we can clear the rocket engine brick wall.
If we cannot, mankind is destined to live and die on this planet when an entire universe awaits. What a sad resignation that would be.

And this attitude is concerning too. You are significantly committed to finding the effect. Not just through your time and financial commitment to building a rig, but because you need it to be real.

With a big effect, a bit of psychological bias doesn't matter. It either flies or it doesn't. But with an effect as tiny and easily confused as the EMDrive, even an experimenter who is honest and genuine can subconsciously bias the results (even if just by dismissing the importance of a confounding factor; as you have with outgassing. Maybe you're right or maybe it's just wishful thinking because you know it's too hard to correct for it if it is an issue, and you already have so many things you need to keep track of.)

Put it another way: What will you do if you didn't get a positive result? Will you believe that you've successfully refuted the original claims? Or will you assume that you've made a mistake (because the effect must be real) and start fiddling with the set-up until you do get a positive response? Note that I'm not calling you a liar, or incompetent, or ungenuine, or too amateurish to be trusted. What I'm saying applies to any professional as much as it does to you, Michelle and others. Commitment-blinkers are really dangerous when playing with effects at the lowest edge of detectability.

Months ago I'd defined the issues I'd be facing in trying to test this device with the equipment I could acquire with the limited funding.

The largest was thermal, by far. I haven't detailed out many of the smaller things I've done yet but maybe it's time I do some of them.

Moving the 140-160c thermal magnetron off from the frustum was the first step in removing a large chaotic thermal effect obscuring any thrust data. I then had the wires and the heat from the frustum to deal with.

Once I had the thermal heat from the magnetron the issue remains of the thermal expansion of the frustum itself. If you want I'll repeat how via end plate construction and resonance capturing by locking the end plates together for mode capturing one or more of the five modes I plan on testing, I'll do so.

The other issue it the effect of the thermal expansion of the high power passing down the fulcrum length in the cables and into the wave-guides (or antennas). All the wires and coax have been laid out to negate as much as possible spurious forces they may generate and even a dummy load has been planed to map out any forces that may effect measurement.

I'm isolating the frustum from air currents with the Faraday cage and plastic covering most of the side windows. The top is open to allow any heat to escape.

The simple quest I started months ago hasn't changed, to pick this device apart bit by bit to ascertain what the effect it is showing is. It's not a perfect test but I hope to be able to negate as many of the error causing issues down to a level that any thrust abnormalities will be easier to detect. How well these "fixes" will fix the problem depend on physics of the system and my building abilities. We have seen data from tests that haven't done any of these things and something was seen from them, not sure what, but something was there. I think I can drop the error levels lower in these first series of tests to see something. And if there is thrust directly related to the Q of the system I covered that too.

I will be going forth and the data will be presented, how that data is worked on is up to the community of believers, on the fencers and nonbelievers. I'm after data and there is no bad data.

Shell

Offline BL

  • Member
  • Posts: 17
  • Liked: 30
  • Likes Given: 0
Re Post #93 by rfmwguy on 8 October:

“Mag sprays rf, pulsed.  Stop pulsing with new power supply.  But, modify mag for sweep.  Spray a bandwidth of swept rf, bound to hit resonance at some point as resonance slowly changes due to thermal changes.

Comments welcomed……..”

The EmDrive principle as I understand it is that a frustum excited at resonance by a microwave signal will produce thrust along the axis of the frustum.  The thrust is proportional to the power applied and the Q of the frustum.

If that is what the DIY’ers are trying to confirm—or reject, it seems unlikely that the hardware they have described on the forum, except for TheTraveller’s, can do either.  The power, frequency, and spectral content of their sources are not known or controllable while testing.  It is not known if the frustum, in its test configuration, has a mode of resonance at the nominal drive frequency.   Due to the spiky spectral content of the source, it is not known how much, if any, energy is being injected at a resonant frequency.  Since each frustum typically has multiple modes of resonance, each at different frequencies, which can be closely spaced, the frustum can only be tested at modes and frequencies that serendipitously coincide with source spectral lines.   It is even possible that the frustum has multiple resonant frequencies within the nominal spectrum width of the source AND, if the frustum has a high Q, that NONE of the energy from the source is supplied at ANY of them. 

Forget modifying the magnetron and/or its power supply.  If you are going to expend your resources in an attempt to test frustum based thrusters, rent or borrow a precision signal generator, or, even better, a Vector Signal Generator (VSG) and a broadband amplifier to get its output up to useful levels.  TheTraveller says that he has located a cheap one that puts out 100w, which should be adequate for proof of principle.

The sig gen can produce AM, FM, or pulse modulation and the spectral content of the VSG output can be tailored to your needs/desires using either canned modulation libraries or by creating your own custom output spectrum.  The frequency step size is typically 1 Hz or smaller, which is adequate for Q’s up to 1e9.  The output spectral width can vary from ultra pure CW to hundreds of MHz.  And you KNOW what you are applying to the frustum.   The modified magnetron approach is the experimental equivalent of hunting deer by going out into the woods, firing 100k rounds of ammo in random directions, and then looking for dead deer.  If you don’t find one, do you conclude that there were no deer in the forest?  Or that the deer were bulletproof?  Or both?

If you don’t want to ‘spray and hope’, keeping a CW source tuned to resonance should be pretty easy by using directional couplers and a power meter to monitor the return loss several times per second and adjusting the CW frequency under software control to ensure that it remains tuned to resonance as the frustum heats. If there are multiple resonant modes with different resonant frequencies the SigGen/VSG approach will allow the frustum to be tested at each and every mode, with the assurance that you have full control of the center frequency, spectrum, and power of the stimulus signal.


The DIY’ers are expending their own time and money, so, other than really hoping that the EmDrive effect is real and wanting to see believable test data confirming it, I have no ‘standing’ to criticize their efforts.  It just seems to me, based on my impressions from reading the forum, that if the objective is to confirm or deny the reality of EmDrive thrust they are wasting both.

Offline Paul451

  • Full Member
  • ****
  • Posts: 1382
  • Australia
  • Liked: 679
  • Likes Given: 575
And this attitude is concerning too. You are significantly committed to finding the effect. Not just through your time and financial commitment to building a rig, but because you need it to be real.
I'm not concerned that the Wright Brothers "wanted" heavier-than-air flight to be real, [...]

{Sigh} You completely ignored what I said immediately after that. Hell, the very next words: "With a big effect, a bit of psychological bias doesn't matter. It either flies or it doesn't."

Instead you ignored what you didn't want to acknowledge in order to get the effect that you wanted.

Offline demofsky

  • Full Member
  • *
  • Posts: 170
  • Liked: 101
  • Likes Given: 1737
The other thing that should be mentioned is that the objective very clearly is to see if we can get a statistically significant signal using the experimental configurations that folks could come up with.  When everyone started down this journey around about thread 2 there was a lot of debate around the Eagleworks vacuum experiments.  One thing that became very clear from this debate is that vacuum experiments produce low micro Newton thrust levels which are exceedingly difficult to parse out from all the potential noise sources, particularly thermal.  Most crucially power levels had to be kept very low to ensure nothing melted in the vacuum!  (If you want critiques wait till your apparatus is near melting!)

Also both Shawyer and Yang did not publish any experiments performed in a vacuum and claimed much higher thrust levels.

The critiques by Tetrakis and Paul451 are just too early in the journey.


Offline Prunesquallor

  • Full Member
  • *
  • Posts: 174
  • Currently, TeV Brane Resident
  • Liked: 157
  • Likes Given: 73
And this attitude is concerning too. You are significantly committed to finding the effect. Not just through your time and financial commitment to building a rig, but because you need it to be real.
I'm not concerned that the Wright Brothers "wanted" heavier-than-air flight to be real, [...]

{Sigh} You completely ignored what I said immediately after that. Hell, the very next words: "With a big effect, a bit of psychological bias doesn't matter. It either flies or it doesn't."

Instead you ignored what you didn't want to acknowledge in order to get the effect that you wanted.

Regardless of size of the effect, it is not unreasonable to expect experimenters to have an expectation (even hope) of the outcome. Regardless of the size of the effect,  physics doesn't care what the experimenter expects. Regardless of the size of the effect, experimental bias (either intentional or unintentional) won't survive the scientific and peer review process.

So i fall to see the distinction you are making.
Retired, yet... not

Offline wallofwolfstreet

  • Full Member
  • *
  • Posts: 165
  • Liked: 169
  • Likes Given: 436
Regardless of size of the effect, it is not unreasonable to expect experimenters to have an expectation (even hope) of the outcome. Regardless of the size of the effect,  physics doesn't care what the experimenter expects. Regardless of the size of the effect, experimental bias (either intentional or unintentional) won't survive the scientific and peer review process.

So i fall to see the distinction you are making.

Quote
physics doesn't care what the experimenter expects.

There is literally a field of psychology devoted to understanding how the above statement isn't correct.  Experimenter bias and how it effects outcomes is a well studied and well understood phenomena.  The double-blind experimental protocol, the gold standard for experimentation, exists solely for the purpose of improving upon the single-blind method by eliminating experimenter bias. 

Quote
Regardless of the size of the effect, experimental bias (either intentional or unintentional) won't survive the scientific and peer review process.

This is just wrong.  Peer review isn't magic.  It can't see through the psychology of an author and determine which data they omitted, which data they squeezed, which data they analyzed using method X because the result was nicer than method Y, etc.  Peer review fails all the time. 

It's a moot point anyway, because we aren't talking about an effect that has been subjected to peer review. 

Offline Blaine

  • Member
  • Posts: 58
  • Spring Hill, KS
  • Liked: 45
  • Likes Given: 122
It doesn't matter what naysayers say.  Btw, their is some awesome news from PaulTheSwag over on reddit.  Check it out.
Weird Science!

Offline glennfish

  • Full Member
  • ***
  • Posts: 388
  • Liked: 281
  • Likes Given: 169
To eliminate gas effects it seems a pressure lower than one microtorr is needed. Such pressures are routinely obtained in large vessels in industry, but need both a roughing pump and a turbomolecular pump/oil diffusion pump (with at least a dry ice/acetone trap) in series and, importantly, a lack of exposed soft parts. UHV metal-metal gaskets would probably be the best and cheapest join type, but cajon or swagelok fittings / welded glass would also work.


I believe that I'm having a hard time finding your assertions credible, your quote being an example.

Granted EM tests at atmospheric preasure at 760 torr see some lift, and this is expected, but  I haven't seen much evidence for hot air balloon flights  at 150,000 feet (28 miles or so), about 1 torr.  In fact, I was suggesting a 10th of a torr, 100 millitorr, for a pump rated to 10 millitorr about 35 mile altitude equivalent.  A relatively cheap embodiment.

You're suggesting a microtorr.  That's a remarkable requirement unless you are in sales for Beckman Coulter or Dynavac.

Science isn't about getting the best equipment.

It's about framing a testable hypothesis and trying to falsify it, followed by replication attempts and reports by many others.  Eventually a consensus may emerge.  Read your Thomas Kuhn and stay away from those parts catalogs.

To your microtorr requirement, I'd be bewildered to see an EM drive hypothesis where the null hypothesis would be rejected because the experimenter operated at 100 millitorr instead of 1 microtorr... But, I'm all ears.

For EM experiments done at atmospheric preassure, while no one finds that ideal, it is possible to frame an hypothesis and an experiment that tests for force under those conditions.  RFMWGUY asked, is the thermal lift retarded when the device is on(?), if so, that is partial (albeit not confirming) evidence.  Thermal lift should not be retarded in a hot air balloon simply because you started spritzing the balloon with microwaves.

It is not axiomatic that it shall fail unless it's done in a vacuum.  Non vacuum testing simply adds to the potential errors and factors to be compensated for.  Careful experimental design and analysis can compensate.

Further, since there is no accepted theory as to why any of this should be real,  for those who want to know, there needs to be testing that is atheoretical to provide a body of observations that ultimately can be used to theorize why, or why not.

Back to lurking.  Wish this site had an ignore poster checkbox.

Offline TheUberOverLord

  • Member
  • Posts: 64
  • U.S.
    • Secure Methods To Display IP Cameras In Websites
  • Liked: 36
  • Likes Given: 7
At this stage of testing and the varying results. Would it not be a bad idea to exclude by default anything?

Others may disagree with me. But the way I see things as they are now. Nobody can state other frequencies let alone other shapes would not provide results.

Any DIY should do as they wish. Of course many will choose similar frequencies, shapes and feeding methods for their frequency injections into similar cavities. With or without a vacuum.

That said. Someone could decide to use a cube with feeds on every side and different frequencies that nobody at this stage could state was a waste of time.

So, I am somewhat amazed at why anyone would want to suggest "These are the 'only' ways to do this testing right!".

At this stage. If someone said they wanted to use a small cavity shaped like a pyramid submerged 100 foot deep in water using AM Radio frequencies at 10 Watts, fed into the small end. I would look forward to their results. Maybe that's just me?

Don
« Last Edit: 10/11/2015 10:23 PM by TheUberOverLord »
EM Drive builders can use these free Interfaces to show their tests live using any IP Cameras in websites Click for live demo examples

Offline rfmwguy

  • EmDrive Builder (retired)
  • Senior Member
  • *****
  • Posts: 2166
  • Liked: 2684
  • Likes Given: 1124
https://www.reddit.com/r/EmDrive/comments/3odlez/science_fair_complete/

Congrats to Paul for winning gold in the south african science fair with his emdrive!

Must have impressed peers and scientists to have made it that far...well done.


Offline rq3

  • Full Member
  • **
  • Posts: 234
  • USA
  • Liked: 276
  • Likes Given: 42
To eliminate gas effects it seems a pressure lower than one microtorr is needed. Such pressures are routinely obtained in large vessels in industry, but need both a roughing pump and a turbomolecular pump/oil diffusion pump (with at least a dry ice/acetone trap) in series and, importantly, a lack of exposed soft parts. UHV metal-metal gaskets would probably be the best and cheapest join type, but cajon or swagelok fittings / welded glass would also work.


I believe that I'm having a hard time finding your assertions credible, your quote being an example.

Granted EM tests at atmospheric preasure at 760 torr see some lift, and this is expected, but  I haven't seen much evidence for hot air balloon flights  at 150,000 feet (28 miles or so), about 1 torr.  In fact, I was suggesting a 10th of a torr, 100 millitorr, for a pump rated to 10 millitorr about 35 mile altitude equivalent.  A relatively cheap embodiment.

You're suggesting a microtorr.  That's a remarkable requirement unless you are in sales for Beckman Coulter or Dynavac.

Science isn't about getting the best equipment.

It's about framing a testable hypothesis and trying to falsify it, followed by replication attempts and reports by many others.  Eventually a consensus may emerge.  Read your Thomas Kuhn and stay away from those parts catalogs.

To your microtorr requirement, I'd be bewildered to see an EM drive hypothesis where the null hypothesis would be rejected because the experimenter operated at 100 millitorr instead of 1 microtorr... But, I'm all ears.

For EM experiments done at atmospheric preassure, while no one finds that ideal, it is possible to frame an hypothesis and an experiment that tests for force under those conditions.  RFMWGUY asked, is the thermal lift retarded when the device is on(?), if so, that is partial (albeit not confirming) evidence.  Thermal lift should not be retarded in a hot air balloon simply because you started spritzing the balloon with microwaves.

It is not axiomatic that it shall fail unless it's done in a vacuum.  Non vacuum testing simply adds to the potential errors and factors to be compensated for.  Careful experimental design and analysis can compensate.

Further, since there is no accepted theory as to why any of this should be real,  for those who want to know, there needs to be testing that is atheoretical to provide a body of observations that ultimately can be used to theorize why, or why not.

Back to lurking.  Wish this site had an ignore poster checkbox.

Look into a Crookes radiometer. They wont work at atmospheric pressure, and they won't work under hard vacuum. The devil is in the details, and it wasn't until fairly recently that anyone understood why they work at all. Folks here are slowly coming around to the protocol that I esposed eons ago, and for which I got a lot of snotty personal e-mails.

I'll say it again:
1) You can't design a cavity which will "tune", at high Q (whatever weird Q method you choose) to a microwave oven magnetron.
2) You can easily design a tuned cavity for any frequency and any mode (common industrial practice).
3) Design a tuned cavity, for the mode of your choice, and use a phase lockable source to drive it.
4) A microwave oven magnetron is a microwave source 100% AM modulated at the rate of its power supply (50-60 Hz).
5) Your phase lockable source should be able to emulate 4 above.

Offline rfmwguy

  • EmDrive Builder (retired)
  • Senior Member
  • *****
  • Posts: 2166
  • Liked: 2684
  • Likes Given: 1124
To eliminate gas effects it seems a pressure lower than one microtorr is needed. Such pressures are routinely obtained in large vessels in industry, but need both a roughing pump and a turbomolecular pump/oil diffusion pump (with at least a dry ice/acetone trap) in series and, importantly, a lack of exposed soft parts. UHV metal-metal gaskets would probably be the best and cheapest join type, but cajon or swagelok fittings / welded glass would also work.


I believe that I'm having a hard time finding your assertions credible, your quote being an example.

Granted EM tests at atmospheric preasure at 760 torr see some lift, and this is expected, but  I haven't seen much evidence for hot air balloon flights  at 150,000 feet (28 miles or so), about 1 torr.  In fact, I was suggesting a 10th of a torr, 100 millitorr, for a pump rated to 10 millitorr about 35 mile altitude equivalent.  A relatively cheap embodiment.

You're suggesting a microtorr.  That's a remarkable requirement unless you are in sales for Beckman Coulter or Dynavac.

Science isn't about getting the best equipment.

It's about framing a testable hypothesis and trying to falsify it, followed by replication attempts and reports by many others.  Eventually a consensus may emerge.  Read your Thomas Kuhn and stay away from those parts catalogs.

To your microtorr requirement, I'd be bewildered to see an EM drive hypothesis where the null hypothesis would be rejected because the experimenter operated at 100 millitorr instead of 1 microtorr... But, I'm all ears.

For EM experiments done at atmospheric preassure, while no one finds that ideal, it is possible to frame an hypothesis and an experiment that tests for force under those conditions.  RFMWGUY asked, is the thermal lift retarded when the device is on(?), if so, that is partial (albeit not confirming) evidence.  Thermal lift should not be retarded in a hot air balloon simply because you started spritzing the balloon with microwaves.

It is not axiomatic that it shall fail unless it's done in a vacuum.  Non vacuum testing simply adds to the potential errors and factors to be compensated for.  Careful experimental design and analysis can compensate.

Further, since there is no accepted theory as to why any of this should be real,  for those who want to know, there needs to be testing that is atheoretical to provide a body of observations that ultimately can be used to theorize why, or why not.

Back to lurking.  Wish this site had an ignore poster checkbox.

Look into a Crookes radiometer. They wont work at atmospheric pressure, and they won't work under hard vacuum. The devil is in the details, and it wasn't until fairly recently that anyone understood why they work at all. Folks here are slowly coming around to the protocol that I esposed eons ago, and for which I got a lot of snotty personal e-mails.

I'll say it again:
1) You can't design a cavity which will "tune", at high Q (whatever weird Q method you choose) to a microwave oven magnetron.
2) You can easily design a tuned cavity for any frequency and any mode (common industrial practice).
3) Design a tuned cavity, for the mode of your choice, and use a phase lockable source to drive it.
4) A microwave oven magnetron is a microwave source 100% AM modulated at the rate of its power supply (50-60 Hz).
5) Your phase lockable source should be able to emulate 4 above.
You are a little out of date. Full wave rectifiers and azmuth magnets are planned to clean up the mag. A solid state source is impracticat at kw power levels with current designs. These are points we've discussed adnauseum since thread 3.

No one is 100% certain the effect is lockable yet. It may be a result of phase amplitude frequency or mode changes. We have tk await a peer reviewed paper before drawing any conclusions about source locking, although it seems likely imho.

Offline Bob Woods

  • Full Member
  • **
  • Posts: 284
  • Salem, Oregon USA
  • Liked: 391
  • Likes Given: 1248
In regards to dissing people as amateurs, it is good to remember that professionals are people who are paid to do science.

Amateurs do it because they love/want to do science.

Either way, in the end it IS science, and that's all that counts.

Offline rq3

  • Full Member
  • **
  • Posts: 234
  • USA
  • Liked: 276
  • Likes Given: 42
To eliminate gas effects it seems a pressure lower than one microtorr is needed. Such pressures are routinely obtained in large vessels in industry, but need both a roughing pump and a turbomolecular pump/oil diffusion pump (with at least a dry ice/acetone trap) in series and, importantly, a lack of exposed soft parts. UHV metal-metal gaskets would probably be the best and cheapest join type, but cajon or swagelok fittings / welded glass would also work.


I believe that I'm having a hard time finding your assertions credible, your quote being an example.

Granted EM tests at atmospheric preasure at 760 torr see some lift, and this is expected, but  I haven't seen much evidence for hot air balloon flights  at 150,000 feet (28 miles or so), about 1 torr.  In fact, I was suggesting a 10th of a torr, 100 millitorr, for a pump rated to 10 millitorr about 35 mile altitude equivalent.  A relatively cheap embodiment.

You're suggesting a microtorr.  That's a remarkable requirement unless you are in sales for Beckman Coulter or Dynavac.

Science isn't about getting the best equipment.

It's about framing a testable hypothesis and trying to falsify it, followed by replication attempts and reports by many others.  Eventually a consensus may emerge.  Read your Thomas Kuhn and stay away from those parts catalogs.

To your microtorr requirement, I'd be bewildered to see an EM drive hypothesis where the null hypothesis would be rejected because the experimenter operated at 100 millitorr instead of 1 microtorr... But, I'm all ears.

For EM experiments done at atmospheric preassure, while no one finds that ideal, it is possible to frame an hypothesis and an experiment that tests for force under those conditions.  RFMWGUY asked, is the thermal lift retarded when the device is on(?), if so, that is partial (albeit not confirming) evidence.  Thermal lift should not be retarded in a hot air balloon simply because you started spritzing the balloon with microwaves.

It is not axiomatic that it shall fail unless it's done in a vacuum.  Non vacuum testing simply adds to the potential errors and factors to be compensated for.  Careful experimental design and analysis can compensate.

Further, since there is no accepted theory as to why any of this should be real,  for those who want to know, there needs to be testing that is atheoretical to provide a body of observations that ultimately can be used to theorize why, or why not.

Back to lurking.  Wish this site had an ignore poster checkbox.

Look into a Crookes radiometer. They wont work at atmospheric pressure, and they won't work under hard vacuum. The devil is in the details, and it wasn't until fairly recently that anyone understood why they work at all. Folks here are slowly coming around to the protocol that I esposed eons ago, and for which I got a lot of snotty personal e-mails.

I'll say it again:
1) You can't design a cavity which will "tune", at high Q (whatever weird Q method you choose) to a microwave oven magnetron.
2) You can easily design a tuned cavity for any frequency and any mode (common industrial practice).
3) Design a tuned cavity, for the mode of your choice, and use a phase lockable source to drive it.
4) A microwave oven magnetron is a microwave source 100% AM modulated at the rate of its power supply (50-60 Hz).
5) Your phase lockable source should be able to emulate 4 above.
You are a little out of date. Full wave rectifiers and azmuth magnets are planned to clean up the mag. A solid state source is impracticat at kw power levels with current designs. These are points we've discussed adnauseum since thread 3.

No one is 100% certain the effect is lockable yet. It may be a result of phase amplitude frequency or mode changes. We have tk await a peer reviewed paper before drawing any conclusions about source locking, although it seems likely imho.

I don't think I'm out of date. In fact I know I'm not. While I'm in awe of your effort, the fact that Freescale, for example, is working on kilowatt level microwave sources for consumer appliances should be evident to everyone involved in this area. Often, a simple phone call will result in donations of equipment, or samples, that the average experimenter can only dream of. You have but to ask, the worst is that they say no.


Offline rfmwguy

  • EmDrive Builder (retired)
  • Senior Member
  • *****
  • Posts: 2166
  • Liked: 2684
  • Likes Given: 1124
To eliminate gas effects it seems a pressure lower than one microtorr is needed. Such pressures are routinely obtained in large vessels in industry, but need both a roughing pump and a turbomolecular pump/oil diffusion pump (with at least a dry ice/acetone trap) in series and, importantly, a lack of exposed soft parts. UHV metal-metal gaskets would probably be the best and cheapest join type, but cajon or swagelok fittings / welded glass would also work.


I believe that I'm having a hard time finding your assertions credible, your quote being an example.

Granted EM tests at atmospheric preasure at 760 torr see some lift, and this is expected, but  I haven't seen much evidence for hot air balloon flights  at 150,000 feet (28 miles or so), about 1 torr.  In fact, I was suggesting a 10th of a torr, 100 millitorr, for a pump rated to 10 millitorr about 35 mile altitude equivalent.  A relatively cheap embodiment.

You're suggesting a microtorr.  That's a remarkable requirement unless you are in sales for Beckman Coulter or Dynavac.

Science isn't about getting the best equipment.

It's about framing a testable hypothesis and trying to falsify it, followed by replication attempts and reports by many others.  Eventually a consensus may emerge.  Read your Thomas Kuhn and stay away from those parts catalogs.

To your microtorr requirement, I'd be bewildered to see an EM drive hypothesis where the null hypothesis would be rejected because the experimenter operated at 100 millitorr instead of 1 microtorr... But, I'm all ears.

For EM experiments done at atmospheric preassure, while no one finds that ideal, it is possible to frame an hypothesis and an experiment that tests for force under those conditions.  RFMWGUY asked, is the thermal lift retarded when the device is on(?), if so, that is partial (albeit not confirming) evidence.  Thermal lift should not be retarded in a hot air balloon simply because you started spritzing the balloon with microwaves.

It is not axiomatic that it shall fail unless it's done in a vacuum.  Non vacuum testing simply adds to the potential errors and factors to be compensated for.  Careful experimental design and analysis can compensate.

Further, since there is no accepted theory as to why any of this should be real,  for those who want to know, there needs to be testing that is atheoretical to provide a body of observations that ultimately can be used to theorize why, or why not.

Back to lurking.  Wish this site had an ignore poster checkbox.

Look into a Crookes radiometer. They wont work at atmospheric pressure, and they won't work under hard vacuum. The devil is in the details, and it wasn't until fairly recently that anyone understood why they work at all. Folks here are slowly coming around to the protocol that I esposed eons ago, and for which I got a lot of snotty personal e-mails.

I'll say it again:
1) You can't design a cavity which will "tune", at high Q (whatever weird Q method you choose) to a microwave oven magnetron.
2) You can easily design a tuned cavity for any frequency and any mode (common industrial practice).
3) Design a tuned cavity, for the mode of your choice, and use a phase lockable source to drive it.
4) A microwave oven magnetron is a microwave source 100% AM modulated at the rate of its power supply (50-60 Hz).
5) Your phase lockable source should be able to emulate 4 above.
You are a little out of date. Full wave rectifiers and azmuth magnets are planned to clean up the mag. A solid state source is impracticat at kw power levels with current designs. These are points we've discussed adnauseum since thread 3.

No one is 100% certain the effect is lockable yet. It may be a result of phase amplitude frequency or mode changes. We have tk await a peer reviewed paper before drawing any conclusions about source locking, although it seems likely imho.

I don't think I'm out of date. In fact I know I'm not. While I'm in awe of your effort, the fact that Freescale, for example, is working on kilowatt level microwave sources for consumer appliances should be evident to everyone involved in this area. Often, a simple phone call will result in donations of equipment, or samples, that the average experimenter can only dream of. You have but to ask, the worst is that they say no.
Thanks, this is a good tip. I moved from tubes to ss many years ago and am glad 1kw ss at 2 ghz is in development. Now, to get that free sample ;)

Offline TheTraveller

In that document, the following statement is made:

Quote
There appears to be a clear dependency between thrust magnitude and the presence of some sort of dielectric RF resonator in the thrust chamber. The geometry, location, and material properties of this resonator must be  valuated using numerous COMSOL® iterations to arrive at a viable thruster solution. We performed some very early evaluations without the dielectric resonator (TE012 mode at 2168 MHz, with power levels up to ~30 watts) and measured no significant net thrust.

Where do they account for outgassing from a big block of plastic under high thermal load?

To make my point again.

The very rapid rise and fall times of the Force signals are way too quick to be either thermal or out gassing generated.

With respect as an engineer to a chemist you are beating a dead horse.

Paul has shared vac data with NSF, which was not that good. Based on my resonance prediction spreadsheets which shows the vac resonance for the EW frustum increases by 600kHz, I asked Paul to do atmo versus vac S11 VNA resonance scans. He confirmed the higher resonance in vac. Surprised him. Told me the existing freq control and/or 3 stub impedance tuner system would not handle that much change. My theory is the early vac data was not done at vac resonance and is why it was crap.

So no biggie, but just another issue to be engineered out. I'm sure Paul & the other EW team members have this sorted.

We need to let EW finish their vac test series and have the results verified by another lab.

We ALL understand what strong positive vac results would mean. So give the professional EW team the time to put together solid vac verification before they publish again and the fire storm erupts.
« Last Edit: 10/12/2015 12:39 AM by TheTraveller »
It Is Time For The EmDrive To Come Out Of The Shadows

Online SeeShells

  • Senior Member
  • *****
  • Posts: 2364
  • Every action there's a reaction we try to grasp.
  • United States
  • Liked: 3089
  • Likes Given: 2660
To eliminate gas effects it seems a pressure lower than one microtorr is needed. Such pressures are routinely obtained in large vessels in industry, but need both a roughing pump and a turbomolecular pump/oil diffusion pump (with at least a dry ice/acetone trap) in series and, importantly, a lack of exposed soft parts. UHV metal-metal gaskets would probably be the best and cheapest join type, but cajon or swagelok fittings / welded glass would also work.


I believe that I'm having a hard time finding your assertions credible, your quote being an example.

Granted EM tests at atmospheric preasure at 760 torr see some lift, and this is expected, but  I haven't seen much evidence for hot air balloon flights  at 150,000 feet (28 miles or so), about 1 torr.  In fact, I was suggesting a 10th of a torr, 100 millitorr, for a pump rated to 10 millitorr about 35 mile altitude equivalent.  A relatively cheap embodiment.

You're suggesting a microtorr.  That's a remarkable requirement unless you are in sales for Beckman Coulter or Dynavac.

Science isn't about getting the best equipment.

It's about framing a testable hypothesis and trying to falsify it, followed by replication attempts and reports by many others.  Eventually a consensus may emerge.  Read your Thomas Kuhn and stay away from those parts catalogs.

To your microtorr requirement, I'd be bewildered to see an EM drive hypothesis where the null hypothesis would be rejected because the experimenter operated at 100 millitorr instead of 1 microtorr... But, I'm all ears.

For EM experiments done at atmospheric preassure, while no one finds that ideal, it is possible to frame an hypothesis and an experiment that tests for force under those conditions.  RFMWGUY asked, is the thermal lift retarded when the device is on(?), if so, that is partial (albeit not confirming) evidence.  Thermal lift should not be retarded in a hot air balloon simply because you started spritzing the balloon with microwaves.

It is not axiomatic that it shall fail unless it's done in a vacuum.  Non vacuum testing simply adds to the potential errors and factors to be compensated for.  Careful experimental design and analysis can compensate.

Further, since there is no accepted theory as to why any of this should be real,  for those who want to know, there needs to be testing that is atheoretical to provide a body of observations that ultimately can be used to theorize why, or why not.

Back to lurking.  Wish this site had an ignore poster checkbox.

Look into a Crookes radiometer. They wont work at atmospheric pressure, and they won't work under hard vacuum. The devil is in the details, and it wasn't until fairly recently that anyone understood why they work at all. Folks here are slowly coming around to the protocol that I esposed eons ago, and for which I got a lot of snotty personal e-mails.

I'll say it again:
1) You can't design a cavity which will "tune", at high Q (whatever weird Q method you choose) to a microwave oven magnetron.
2) You can easily design a tuned cavity for any frequency and any mode (common industrial practice).
3) Design a tuned cavity, for the mode of your choice, and use a phase lockable source to drive it.
4) A microwave oven magnetron is a microwave source 100% AM modulated at the rate of its power supply (50-60 Hz).
5) Your phase lockable source should be able to emulate 4 above.
That's not quite correct on the microwave magnetron power supply. Panasonic has a Inverter type that doesn't have a duty cycle at the incoming line frequencies. It's output around 33KHz can be stabilized  with filtering and modifying the final stage to not even have the 33KHz component. The heater can be turned off after powering on for an increased clean signal.

One reason I want the wider output in bandwidth by using a magnetron is simply to be able to test the same cavity by keeping the wider band input of the magnetron with it's sub-harmonics and physically sweep the cavity length through tune points crossing through multiple modes, consisting of both TE and even TM modes. As the cavity is now with a meep simulated 30MHz bandwidth it operates in 3 different modes (one being a 1.5 hybrid mode) all within the same cavity and it still maintains a high reported Q. Why does it do this and what profound (or not) effects will be seen by testing these other close modes? No one can answer that for me because it's never been done.

Shell

Offline rfmwguy

  • EmDrive Builder (retired)
  • Senior Member
  • *****
  • Posts: 2166
  • Liked: 2684
  • Likes Given: 1124
Shell, I've followed your design logic for some time now and am impressed by your analysis and plans. This could be a millinewton level ke force your about to measure, well above the snowflake levels we've had to deal with. My phase II is a 17.5 millinewton goal, I may need some power supply help from you or phil.

Offline TheTraveller

Shell, I've followed your design logic for some time now and am impressed by your analysis and plans. This could be a millinewton level ke force your about to measure, well above the snowflake levels we've had to deal with. My phase II is a 17.5 millinewton goal, I may need some power supply help from you or phil.

I suspect the 1st DIY result >= 10mN should be offered to EW to  confirm as like a strong positive EW vac result, a fire storm will erupt.

As long as the results are in the show flake range (~30uN), the critics will hold their fire as easy to dismiss.

At 10mNs it all changes. Shawyers 1st Experimental at 16mNs got him serious funding from the UK gov, which he turned into the rotary Demonstrator and then the Flight Thruster. It is interesting to observe that as his Force generated grew, his credibility decreased until he was called a fraud and ignored.

Hopefully with the openness of the Internet, that may be avoided this time around as the EMDrive DIYers learn what Shawyer learned back in 1996 - 2006 and our EMDrive Force generation slowly increases until it can't be ignored or called fraud and discredited.
It Is Time For The EmDrive To Come Out Of The Shadows

Offline aceshigh

  • Full Member
  • ****
  • Posts: 636
  • Liked: 190
  • Likes Given: 16
. I'm after data and there is no bad data.

Shell

I disagree


:)

keep up the good work SeeShells

Tags: