Author Topic: EM Drive Developments - related to space flight applications - Thread 3  (Read 1878361 times)

Offline DrBagelBites

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Trying to grasp the conjecture about vibration or ratcheting of the EM Drive and how best to ask Tajmar about it, and what should experimenters like RFMWGUY and Shell and DrBagelBytes do about it.

As I understand TheTraveller, he has decided the (only ?) satisfactory way to measure the elusive "EMDrive thrust" is to conduct an experiment on a rotating device mounted on a bearing. 

1) As I understand it, that means that he finds it unsatisfactory to measure the elusive "EMDrive thrust" not just using mechanical scales but also the teeter-totter and laser pointer that RFMWGUY and SeeShells and DrBagelBytes are planning to use.  Is that correct?

2) If that is so, what is the best thing that  RFMWGUY or SeeShells  or DrBagelBytes (or Tajmar or NASA)  can do to "motivate" the EM Drive with their set-up? Is it just to tap it? Or vibrating it, if so how, with what, at what frequency, amplitude and by how much?

3) How are testers going to strike a balance between eliminating background forces (the motion of the teeter totter that RFMWGUY and Dr.BagelBytes have shown due to air convection) and "motivating" the EM Drive?

If the EMDrive is not free to accelerate, the limited compression distance for movement a scale may offer, offers little ability to show what it can really do when it is free to accelerate without constraint.

Scales will still show some Force generation but it may not be the best showing.

Unless the experimenter has gone to extreme lengths to eliminate vibration, vibration will be there. Additionally the big end will experience significant sound vibratory Force shoving it gently toward to small end, which will experience less sound vibratory Forces due to reduced surface area.

I believe the lack of sound vibratory forces action on the big end is why Eagleworks experienced reduce Force generation in a vacuum.
Concerning the upcoming presentation by Prof. Tajmar from The Technische Universität Dresden at the AIAA meeting, and assuming what I heard from several sources is correct that:

1) The Technische Universität Dresden measured less than 50 microNewtons force from the EM Drive with several hundred Watts in vacuum, under different orientations

2) That Tajmar says he doesn't know about the vibration/ratcheting conjecture to motivate the EM Drive thrust

how could someone like DrBagelBytes best ask Tajmar during his presentation at the AIAA meeting about whether Tajmar's University team measured such low forces due to the vibration/ratcheting conjecture to motivate the EM Drive thrust, in as few words as possible while simultaneously explaining to Tajmar at the Q/A session what this conjecture is all about?

Good thing we have ample time to formulate these questions. However, are we completely sure that his results were so low? Is this confirmed? Or just rumors? I'm sure you have friends in higher places than I do, so I'll trust your thought on it.

Also, would you want me to mention that I am asking on behalf of the NasaSpaceFlight forum?


Offline TheTraveller

3) How are testers going to strike a balance between eliminating background forces (the motion of the teeter totter that RFMWGUY and Dr.BagelBytes have shown due to air convection) and "motivating" the EM Drive?

That is one of the things that bothers me about Shawyer's theory. Even with the rotating setup, how is the tester going to get good data. It will be even harder to reduce background forces on a rotating platform.

The thing that bothers me the most about Shawyer's theory is that no thrust is seen by a stationary drive. That's the same result you would get if EM drives didn't work at all.

Now I'm not saying Shawyer is wrong, it's just that maybe testing his theory is beyond the capacity of DIY testers. Perhaps some vibration is enough for some thrust, but different test rigs will have different levels of vibration resulting in different thrust measurements. As TheTraveller wrote, it could explain the lower thrust results by Eagleworks.

I would like to see EM drive testing for stationary horizontal setups to be rotated by say 30 to 60 degrees between test series. If the thrust changes as the drive position changes, that would indicate an interaction with the Earth's magnetic field.

In a rotating test rig, does the thrust vary based on the position of the drive? Are there enough data points during a test run to look into that question?

In vertical drive setups, changing the angle would show how drive orientation reacts with Earth's gravitational field. Of course, that would make measuring thrust more difficult.

To all the testers out there, be safe and good luck.

On a rotating table, with no connecting cords, the cavity is free to accelerate for as long as there is power, which is not the case on a scale as it can only accelerate until the scale reaches compressive equilibrium and then the EMDrive stops.

Many simple ways to record the increasing angular acceleration on a rotating table.

There is no interaction with the Earth gravity field as the guide wavelength and thus group velocity is fixed as the the cavity dimensions. EM waves inside the cavity are not free to act as they do outside the cavity.

Shawyer has already tried all that stuff and more. Here is a portion of his report to the UK gov, which was checked by 7 UK aerospace firms and academics appointed and controlled by the UK Dept of Defense.

Attached is the test rig he used for his 1st Experimental EMDrive.
« Last Edit: 07/07/2015 04:48 PM by TheTraveller »
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Offline Rodal

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...

Good thing we have ample time to formulate these questions. However, are we completely sure that his results were so low? Is this confirmed? Or just rumors? I'm sure you have friends in higher places than I do, so I'll trust your thought on it.

Also, would you want me to mention that I am asking on behalf of the NasaSpaceFlight forum?
1) People can independently phone call The Technische Universität Dresden, Institute for Aerospace Engineering, Space Systems, Breakthrough Propulsion Physics research, to verify the information.

2) There is always the possibility that my information will be stale by the time that Prof Tajmar makes his presentation: they can continue to get more data until the oral presentation.

3) If what he presents is different: that's the reason to have several questions prepared, and adapt what you actually ask according to what he actually presents.  Don't assume that you will get to ask more than one question, if one at all, as for example:

a) the AIAA session may run late due to other presenters not abiding by their time allotments.  Tajmar's EM Drive presentation is the last one that day, and it may happen that they may have to curtail the Q/A time (it has happened many times before)

b) there will be many people wanting to ask questions, so you may not get the chance to ask any questions.

4) No. I would not suggest to pose a question on behalf of an Internet Forum.
« Last Edit: 07/07/2015 06:16 PM by Rodal »

Offline DrBagelBites

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1) People can independently phone call The Technische Universität Dresden, Institute for Aerospace Engineering, Space Systems, Breakthrough Propulsion Physics research, to verify the information

2) No. I would not suggest to pose a question on behalf of an Internet Forum.

Fair enough. As I said before, plenty of time to formulate and agree on a question.

Perhaps the tact would be: 1. Give small background of ratchet/vibration conjecture, then 2. Pose question about it to Prof. Tajmar. Interlacing the question with the background I think would be awfully confusing.

Edit: And just an idea, but perhaps a simple poll would be a good idea to see which questions pique the interest of readers/commenters.
« Last Edit: 07/07/2015 04:55 PM by DrBagelBites »

Offline SeeShells

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Trying to grasp the conjecture about vibration or ratcheting of the EM Drive and how best to ask Tajmar about it, and what should experimenters like RFMWGUY and Shell and DrBagelBytes do about it.

As I understand TheTraveller, he has decided the only satisfactory way to measure the elusive "EMDrive thrust" is to conduct an experiment on a rotating device mounted on a bearing. 

1) As I understand it, that means that he finds it unsatisfactory to measure the elusive "EMDrive thrust" not just using mechanical scales but also the teeter-totter that RFMWGUY and SeeShells are planning to use.  Is that correct?

2) If that is so, what is the best thing that  RFMWGUY or SeeShells (or Tajmar or NASA)  can do to "motivate" the EM Drive with their set-up? Is it just to tap it? Or vibrating it, if so how, with what, at what frequency, amplitude and by how much?

3) How are testers going to strike a balance between eliminating background forces (the motion of the teeter totter that RFMWGUY and Dr.BagelBytes have shown due to air convection) and "motivating" the EM Drive?

I see in every test jig which tries to measure movement subject to outside forces that can not be isolated. With the rotary table you have the issues of precession (spinning top https://en.wikipedia.org/wiki/Precession) and balancing the device which maybe a have a even slight asymetrical weight distribution.

If you turn the rotating table on its side 90 degrees and balance it to have a uniform weight distribution so no one side will rotate to the bottom you have a balanced beam action, which we are building.

Even within a closed cavity like TT is building heat will increase or decrease the local density of the air not a large effect but another one we have to deal with.

The torsional horizontal balance beam seemed to be a trade off in building and increased thermal issues. I have a perforated cavity which will allow any heated air to escape and then I only have the heated air rising from the frustum to worry about in my calculations.

I will have isolated the beam from local vibrations by using only two points secured to the  beam by SS cables to the top of the 10 foot gantry which is secured into bedrock with a 36 inch concrete base.

A static test is to be preformed measuring and recording any vibrational frequencies and directions that may still make it through to the beam and the average "noise level" will help in the base line numbers.

I'll be using a laser secured to the center pivot point of the 12 foot beam reflected off a mirror on the end of the beam with the frustum, shooting across parallel to the top of the beam to a stable target supported on a variable mass anti-vibration platform. In the static test this should show any external movements on the beam.

The local area around the frustum will be fully enclosed in a double walled Faraday cage comprised of a heavier gauge wire extruded form (support) and with copper fine mesh over the top of it. I'll be building the external frame using 2"x2" wooden beams. Where any sections of fine mesh meet I plan to overlay another fine wire mesh to prevent any leakage or incoming RF frequencies. the area that is around the beam and measuring devices will be enclosed  from ceiling to floor using a clear heavy .010 thick PETG plastic sheeting to dampen air circulations.

I plan on documenting and videoing the setup. Including cables, , Magnetron signal generation in the closed faraday cage below and at the center of the fulcrum, spectral data on injected signal will be from the manufacture of the magnetron.

I'm currently trying to enlist the help of some local Hams to "borrow" a VNA and power meters for the DUT. Then we can get the spectral data in the DUT in the faraday cage and outside, all the data on the equipment will be recorded. Still working on that.

All physical distances will be measured and recorded.

That's about it so far and if I missed something I'll post it or if you have questions please ask or suggestions I'm very open.

Shell

Offline TheTraveller

Roger Shawyer's IAC 2014 paper has been peer reviewed and accepted for publication in Acta Astronautica, the IAF journal.

I just finished reading this paper and don't believe any outstanding questions have been answered.  In the abstract Mr. Shawyer mentions a high temperature superconductor cavity.   There are dimensions and expectations of the performance of this HTS cavity but no mention of any experiments or any data that has been collected.   The rest of the paper is devoted to descriptions of hypothetical space drives and dubious math.

You seem to have ignored the 1st 3 pages of the paper and the various statements made there confirming for the 2nd time in a peer reviewed paper (Chinese peer review was 1st) the EMdrive generates Force as claimed.

There are very significant statements made in the 1st 3 pages, that are now peer reviewed statements and must be taken as fact.

As to your claim of dubious math, you will be writing to Acta Astronautica with your criticism? Will be looking forward to reading your conversation with the peer reviewers.
« Last Edit: 07/07/2015 05:07 PM by TheTraveller »
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Offline SeeShells

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Trying to grasp the conjecture about vibration or ratcheting of the EM Drive and how best to ask Tajmar about it, and what should experimenters like RFMWGUY and Shell and DrBagelBytes do about it.

As I understand TheTraveller, he has decided the only satisfactory way to measure the elusive "EMDrive thrust" is to conduct an experiment on a rotating device mounted on a bearing. 

1) As I understand it, that means that he finds it unsatisfactory to measure the elusive "EMDrive thrust" not just using mechanical scales but also the teeter-totter that RFMWGUY and SeeShells are planning to use.  Is that correct?

2) If that is so, what is the best thing that  RFMWGUY or SeeShells (or Tajmar or NASA)  can do to "motivate" the EM Drive with their set-up? Is it just to tap it? Or vibrating it, if so how, with what, at what frequency, amplitude and by how much?

3) How are testers going to strike a balance between eliminating background forces (the motion of the teeter totter that RFMWGUY and Dr.BagelBytes have shown due to air convection) and "motivating" the EM Drive?

I see in every test jig which tries to measure movement subject to outside forces that can not be isolated. With the rotary table you have the issues of precession (spinning top https://en.wikipedia.org/wiki/Precession) and balancing the device which maybe a have a even slight asymetrical weight distribution.

If you turn the rotating table on its side 90 degrees and balance it to have a uniform weight distribution so no one side will rotate to the bottom you have a balanced beam action, which we are building.

Even within a closed cavity like TT is building heat will increase or decrease the local density of the air not a large effect but another one we have to deal with.

The torsional horizontal balance beam seemed to be a trade off in building and increased thermal issues. I have a perforated cavity which will allow any heated air to escape and then I only have the heated air rising from the frustum to worry about in my calculations.

I will have isolated the beam from local vibrations by using only two points secured to the  beam by SS cables to the top of the 10 foot gantry which is secured into bedrock with a 36 inch concrete base.

A static test is to be preformed measuring and recording any vibrational frequencies and directions that may still make it through to the beam and the average "noise level" will help in the base line numbers.

I'll be using a laser secured to the center pivot point of the 12 foot beam reflected off a mirror on the end of the beam with the frustum, shooting across parallel to the top of the beam to a stable target supported on a variable mass anti-vibration platform. In the static test this should show any external movements on the beam.

The local area around the frustum will be fully enclosed in a double walled Faraday cage comprised of a heavier gauge wire extruded form (support) and with copper fine mesh over the top of it. I'll be building the external frame using 2"x2" wooden beams. Where any sections of fine mesh meet I plan to overlay another fine wire mesh to prevent any leakage or incoming RF frequencies. the area that is around the beam and measuring devices will be enclosed  from ceiling to floor using a clear heavy .010 thick PETG plastic sheeting to dampen air circulations.

I plan on documenting and videoing the setup. Including cables, , Magnetron signal generation in the closed faraday cage below and at the center of the fulcrum, spectral data on injected signal will be from the manufacture of the magnetron.

I'm currently trying to enlist the help of some local Hams to "borrow" a VNA and power meters for the DUT. Then we can get the spectral data in the DUT in the faraday cage and outside, all the data on the equipment will be recorded. Still working on that.

All physical distances will be measured and recorded.

That's about it so far and if I missed something I'll post it or if you have questions please ask or suggestions I'm very open.

Shell

Offline DrBagelBites

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I see in every test jig which tries to measure movement subject to outside forces that can not be isolated. With the rotary table you have the issues of precession (spinning top https://en.wikipedia.org/wiki/Precession) and balancing the device which maybe a have a even slight asymetrical weight distribution.

If you turn the rotating table on its side 90 degrees and balance it to have a uniform weight distribution so no one side will rotate to the bottom you have a balanced beam action, which we are building.

Even within a closed cavity like TT is building heat will increase or decrease the local density of the air not a large effect but another one we have to deal with.

The torsional horizontal balance beam seemed to be a trade off in building and increased thermal issues. I have a perforated cavity which will allow any heated air to escape and then I only have the heated air rising from the frustum to worry about in my calculations.

I will have isolated the beam from local vibrations by using only two points secured to the  beam by SS cables to the top of the 10 foot gantry which is secured into bedrock with a 36 inch concrete base.

A static test is to be preformed measuring and recording any vibrational frequencies and directions that may still make it through to the beam and the average "noise level" will help in the base line numbers.

I'll be using a laser secured to the center pivot point of the 12 foot beam reflected off a mirror on the end of the beam with the frustum, shooting across parallel to the top of the beam to a stable target supported on a variable mass anti-vibration platform. In the static test this should show any external movements on the beam.

The local area around the frustum will be fully enclosed in a double walled Faraday cage comprised of a heavier gauge wire extruded form (support) and with copper fine mesh over the top of it. I'll be building the external frame using 2"x2" wooden beams. Where any sections of fine mesh meet I plan to overlay another fine wire mesh to prevent any leakage or incoming RF frequencies. the area that is around the beam and measuring devices will be enclosed  from ceiling to floor using a clear heavy .010 thick PETG plastic sheeting to dampen air circulations.

I plan on documenting and videoing the setup. Including cables, , Magnetron signal generation in the closed faraday cage below and at the center of the fulcrum, spectral data on injected signal will be from the manufacture of the magnetron.

I'm currently trying to enlist the help of some local Hams to "borrow" a VNA and power meters for the DUT. Then we can get the spectral data in the DUT in the faraday cage and outside, all the data on the equipment will be recorded. Still working on that.

All physical distances will be measured and recorded.

That's about it so far and if I missed something I'll post it or if you have questions please ask or suggestions I'm very open.

Shell

I'm a little confused by your laser setup. Is the laser stationary? Or allowed to rotate with the beam? And the mirror is attached to the end of the beam? Maybe I am over thinking it, or it is the lack of sleep, but my brain doesn't visualize what you are doing.  ???

Offline SeeShells

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https://en.wikipedia.org/wiki/Weighing_scale

A good article summation on simple ways to measure stuff... ;) and the problems.

Offline SeeShells

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That's about it so far and if I missed something I'll post it or if you have questions please ask or suggestions I'm very open.

Shell

I'm a little confused by your laser setup. Is the laser stationary? Or allowed to rotate with the beam? And the mirror is attached to the end of the beam? Maybe I am over thinking it, or it is the lack of sleep, but my brain doesn't visualize what you are doing.  ???
No the laser is secured to the center of the beam.
Kinda like this... sorry for the quicky in paint.
Shell

Note: Added second laser to setup for control. A sharp lurker here and bless them saw that the PDF and my how I explained it was different. My bad and thanks to them for getting it.
« Last Edit: 07/07/2015 05:52 PM by SeeShells »

Offline Rodal

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https://en.wikipedia.org/wiki/Weighing_scale

A good article summation on simple ways to measure stuff... ;) and the problems.
OK, you have thoroughly covered the issues regarding different testing methods.

What do you think of the conjecture that the EM Drive needs to be "motivated" by external vibrations (of unspecified magnitude and frequency) in order to show thrust? and how are you planning to motivate the EM Drive to exhibit such forces?  As I understand it from TheTraveller, he is saying that unless you so motivate the EM Drive you will measure very small forces.

Offline WarpTech

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https://en.m.wikipedia.org/wiki/Microwave_cavity#Cylindrical_cavity

Now I see where the expressions comes from.

The cut off frequency expressions for constant radius R cilindrical waveguide.

It's wrong because,  the expressions for constant radius waveguides are used like dispersions relations of a tappered waveguide , and the " constant radius R" is used as a function of spacial coordinates.
 Not only this, derivatives of this  expressions are done acting on the"ad-hoc" spacial dependency introduced.

Wrong!!!

I don't think so. You, yourself posted,

This guys think another way

http://arxiv.org/abs/0708.3519

:)

In the first paragraph of section 4 of this paper, they decompose the wave vector into time-like and space-like, orthogonal components. This is a more precise derivation of exactly what I am doing. The space-like component must shift mass to match the boundary conditions as the time-like component travels down the waveguide.

It seems you "believe" waveguides are linear and cannot deviate from this expectation. In the case of a tapered waveguide, it mimics gravity which is non-linear. So, I still do not see what is "wrong" with my equation. Although, now I do see a better way to derive it and reference it. Thank you!
Todd

The field equations are linear ( any linear combination of field solutions is a solution too).
Non linear are the dispersion relations between frequency (omega) and the wave number(kappa), and this relationship is ditacted solving the maxwell /helmoltz equations for each geometry, boundary conditions and medium of the problem under analysis, and both omega and kappa never has a espatial or temporal dependence just because they are eigenvalues of the differential operators envolved, and the modes are the eigenvectors.
When you put a ad-hoc coordinate dependence you are automaticaly, not solving the original equation.
The waveguide or cavity can be any shape,  and linearity is not related to it.
When you take the wikipedia expression for cut off frequency of e regular cylindrical waveguide, and change the constant radius R of the expression for a function of z coordinate in your expression, automatically your expression is not more consistent with the equations, basically because if c a constant, f is a function and d is a differential operator, them d(cf)=cd(f) ,  but if c is now a function then d(cf)=d(c)f+cd(f), and this new term d(c)f  will make the equations not be satisfied, neither the boundary conditions.
The article has a decomposition like any orthogonal decomposition, and if you had noted, all wave numbers kappa are constants.
You have done a transformation inofensive for algebric equation solutions, but for differential equations is wrong.
And if are trying describe fotons in a gravitational field using that same "procedures" you are in error again, because fotons in general relativity also must satisfy differential equations called null geodesic equations.

Please show us the "correct" dispersion relationship for a tapered waveguide then. It is simple to solve the boundary condition for a straight non-tapered waveguide. Show us how to do it for a tapered waveguide, without parameterizing the radius with respect to z. Show us how to derive and solve the differential equations for a tapered waveguide. I defer to your expertise!

Thank you.
Just FYI: My degree is in Quantum Optics, Lasers and Holography, and I have 35 years of experience in power electronics. So I understand resonance and I understand what you are saying. I know how to solve differential equations. If you are expecting a linear solution in a tapered waveguide,  you will not find one.
Todd

Offline DrBagelBites

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That's about it so far and if I missed something I'll post it or if you have questions please ask or suggestions I'm very open.

Shell

I'm a little confused by your laser setup. Is the laser stationary? Or allowed to rotate with the beam? And the mirror is attached to the end of the beam? Maybe I am over thinking it, or it is the lack of sleep, but my brain doesn't visualize what you are doing.  ???
No the laser is secured to the center of the beam.
Kinda like this... sorry for the quicky in paint.
Shell

Thanks for the visual! Definitely need more coffee. :)

Offline zen-in

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Roger Shawyer's IAC 2014 paper has been peer reviewed and accepted for publication in Acta Astronautica, the IAF journal.

I just finished reading this paper and don't believe any outstanding questions have been answered.  In the abstract Mr. Shawyer mentions a high temperature superconductor cavity.   There are dimensions and expectations of the performance of this HTS cavity but no mention of any experiments or any data that has been collected.   The rest of the paper is devoted to descriptions of hypothetical space drives and dubious math.

You seem to have ignored the 1st 3 pages of the paper and the various statements made there confirming for the 2nd time in a peer reviewed paper (Chinese peer review was 1st) the EMdrive generates Force as claimed.

There are very significant statements made in the 1st 3 pages, that are now peer reviewed statements and must be taken as fact.

As to your claim of dubious math, you will be writing to Acta Astronautica with your criticism? Will be looking forward to reading your conversation with the peer reviewers.

The paper starts off describing a superconducting cavity but nowhere is it stated that any experiments were done with this cavity and there is no new data.   "Significant statements" are not enough when extraordinary claims are being made.   If there is no data to back up these claims then any theoretical work; ie: math, projections, etc; are moot.   There are many physicists more competent than I who have disputed Mr Shawyer's math.

Offline aero

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@Rodal-
Meep can output the time slices as frequently as desired, up to once per time step, or 6527 h5 file time indices (data sets) per run. So instead 10 h5 data sets/cycle, there would result just over 200 h5 data sets/cycle. Neither I nor my computer can deal with that much data over a full run. It would be much smaller impact to increase the run time beyond 32 cycles.

As for increasing the csv data frequency, better to install the latest Meep from source, then explore the use of the newer features of the software to reduce the data at run time, prior to output. That means we would need to drop back 5 and punt, for now, but later we might have a stronger meep to support our efforts.
Retired, working interesting problems

Offline ElizabethGreene

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No the laser is secured to the center of the beam.
Kinda like this... sorry for the quicky in paint.
Shell
You can double your resolution by fixing the mirror to the beam pivot and bouncing the laser off of it.  That's how the Nichols radiometer worked.  If you are expecting a tiny displacement, then an optical lever http://badger.physics.wisc.edu/lab/manual/node33_mn.html is another option.

Yes, I'm stalking.. but no new ideas today.  Yet. :D


... And if you haven't read SevenEves yet, go grab it.  We'll be here when you get back.

Offline TheTraveller

Roger Shawyer's IAC 2014 paper has been peer reviewed and accepted for publication in Acta Astronautica, the IAF journal.

I just finished reading this paper and don't believe any outstanding questions have been answered.  In the abstract Mr. Shawyer mentions a high temperature superconductor cavity.   There are dimensions and expectations of the performance of this HTS cavity but no mention of any experiments or any data that has been collected.   The rest of the paper is devoted to descriptions of hypothetical space drives and dubious math.

You seem to have ignored the 1st 3 pages of the paper and the various statements made there confirming for the 2nd time in a peer reviewed paper (Chinese peer review was 1st) the EMdrive generates Force as claimed.

There are very significant statements made in the 1st 3 pages, that are now peer reviewed statements and must be taken as fact.

As to your claim of dubious math, you will be writing to Acta Astronautica with your criticism? Will be looking forward to reading your conversation with the peer reviewers.

The paper starts off describing a superconducting cavity but nowhere is it stated that any experiments were done with this cavity and there is no new data.   "Significant statements" are not enough when extraordinary claims are being made.   If there is no data to back up these claims then any theoretical work; ie: math, projections, etc; are moot.   There are many physicists more competent than I who have disputed Mr Shawyer's math.

The extraordinary claims made in the 1st 3 pages, especially in Table 1 on page 1, which mean the mentioned EMDrives work as claimed and are now peer reviewed history. Accept them as factual and move on to new fields.

As for your other physicists, I sure hope they have not dug themselves in so deep, they can't retract their views.
« Last Edit: 07/07/2015 05:57 PM by TheTraveller »
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.”
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Offline Rodal

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@Rodal-
Meep can output the time slices as frequently as desired, up to once per time step, or 6527 h5 file time indices (data sets) per run. So instead 10 h5 data sets/cycle, there would result just over 200 h5 data sets/cycle. Neither I nor my computer can deal with that much data over a full run. It would be much smaller impact to increase the run time beyond 32 cycles.

As for increasing the csv data frequency, better to install the latest Meep from source, then explore the use of the newer features of the software to reduce the data at run time, prior to output. That means we would need to drop back 5 and punt, for now, but later we might have a stronger meep to support our efforts.

No, as I wrote in my previous (bold added for emphasis):

<<Looking forward, since the size of the file is an issue,I think it may be better to stay with your present number of time steps per cycle (10) and just increase the number of cycles (you only output 2 cycles from which I could obtain the Poynting Vector), to explore the shape of the curve, as that would give us information about the growth of the Poynting vector with time and also give us information about whether this is just a transient or not.  >>

as I said, given the present size constraints we are much better off using the same number of time steps (10) per time slice, and exploring more time steps, than outputting every time step as a time slice.
« Last Edit: 07/07/2015 06:00 PM by Rodal »

Offline SeeShells

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https://en.wikipedia.org/wiki/Weighing_scale

A good article summation on simple ways to measure stuff... ;) and the problems.
OK, you have thoroughly covered the issues regarding different testing methods.

What do you think of the conjecture that the EM Drive needs to be "motivated" by external vibrations (of unspecified magnitude and frequency) in order to show thrust? and how are you planning to motivate the EM Drive to exhibit such forces?  As I understand it from TheTraveller, he is saying that unless you so motivate the EM Drive you will measure very small forces.

TT may be right, I don't know, some love it some think it's poo. I'm indifferent. I'm after data. But Jose I plan on running it with out any external push or pull. If nothing happens in the vertical or 180 or even 90 degree rotations than I have a small weight to drop onto the beam in static conditions and than record it and then in activation of the frustum. Well take it from there.

Shell

 

1) People can independently phone call The Technische Universität Dresden, Institute for Aerospace Engineering, Space Systems, Breakthrough Propulsion Physics research, to verify the information

2) No. I would not suggest to pose a question on behalf of an Internet Forum.

Fair enough. As I said before, plenty of time to formulate and agree on a question.

Perhaps the tact would be: 1. Give small background of ratchet/vibration conjecture, then 2. Pose question about it to Prof. Tajmar. Interlacing the question with the background I think would be awfully confusing.

Edit: And just an idea, but perhaps a simple poll would be a good idea to see which questions pique the interest of readers/commenters.

I would not be terribly surprised if Martin Tajmar is reading this forum.

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