### Author Topic: EM Drive Developments - related to space flight applications - Thread 3  (Read 2264983 times)

#### aero

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##### Re: EM Drive Developments - related to space flight applications - Thread 3
« Reply #2720 on: 06/26/2015 06:11 PM »
...

Thanks...quite confusing, I must admit in the early stages of this project...9.0 vs 10.2"L. Suppose the logical way to go is 10.2 since it will be far easier to reduce length than to add it. Rodal says 10.2, Aero sees resonance at 9.0. ...
Well, my reading is that @aero is not confused on this, as he (apparently, from his last message) understood that I had showed you that there is resonance at 9.0 inches and there is resonance at 10.2 inches.  So I don't understand why you state <<Rodal says 10.2, Aero sees resonance at 9.0>>

The correct statement should read instead:

<<Rodal states resonance at L=9.0 inches and at L=10.2 inches, Aero sees resonance at L=9.0 inches and aero has not yet run L=10.2 inches>>

As far as I know @aero HarmInv has big issues with convergence, he has to add noise to get convergence in a finite time, and has to input a frequency very close to the answer to get an answer.  So he has to know the answer in order to get an answer.  And as far as I know he hasn't tried 10.2 inches yet, and he doesn't know what mode shape was his resonance at 9.0 inches. And to get resonance at 9.0 inches length, he had to input the same frequency and dimensions that I used to get resonance at 9.0 inches.  So where is the confusion?

To clarify @aero's result we must wait until he runs some more runs, so that he can see what mode shape he converged to, and to see what he gets with L=10.2 inches.

More data is forthcoming. First, field patterns at 9.0 inch length then resonance runs in 10.2 inch cavity followed by field patterns.
Retired, working interesting problems

#### rfmwguy

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##### Re: EM Drive Developments - related to space flight applications - Thread 3
« Reply #2721 on: 06/26/2015 06:20 PM »
...

Thanks...quite confusing, I must admit in the early stages of this project...9.0 vs 10.2"L. Suppose the logical way to go is 10.2 since it will be far easier to reduce length than to add it. Rodal says 10.2, Aero sees resonance at 9.0. ...
Well, my reading is that @aero is not confused on this, as he (apparently, from his last message) understood that I had showed you that there is resonance at 9.0 inches and there is resonance at 10.2 inches.  So I don't understand why you state <<Rodal says 10.2, Aero sees resonance at 9.0>>

The correct statement should read instead:

<<Rodal states resonance at L=9.0 inches and at L=10.2 inches, Aero sees resonance at L=9.0 inches and aero has not yet run L=10.2 inches>>

As far as I know @aero HarmInv has big issues with convergence, he has to add noise to get convergence in a finite time, and has to input a frequency very close to the answer to get an answer.  So he has to know the answer in order to get an answer.  And as far as I know he hasn't tried 10.2 inches yet, and he doesn't know what mode shape was his resonance at 9.0 inches. And to get resonance at 9.0 inches length, he had to input the same frequency and dimensions that I used to get resonance at 9.0 inches.  So where is the confusion?

To clarify @aero's result we must wait until he runs some more runs, so that he can see what mode shape he converged to, and to see what he gets with L=10.2 inches.

Thanks Doc, a 10.2 run would be much appreciated.

#### WarpTech

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##### Re: EM Drive Developments - related to space flight applications - Thread 3
« Reply #2722 on: 06/26/2015 06:21 PM »

...I've also found a mechanism to boost the force many times over that of a photon rocket, such that this little bit of energy that escapes may in fact be enough to cause the observed thrust.

More when I finish the paper...
Todd

I would be interested to hear what component it could be that would multiply the thrust.  Would there be that much more radiation emitted?

When I've checked, rechecked, and validated my equations, I'll let you know. I ran a spreadsheet last night to determine the required stored energy for a given force. The numbers seem reasonable given the available data, "IFF" there were no plate on the big end and the flux could get out. With the big end sealed, the force is there, but it's cancelled at the big end. It's not going to do anything unless the flux can get out.

One of the key issues I've tried to answer is, what is the drift velocity of an Xnm mode in a tapered cylinder cavity? In a straight cylindrical cavity, a resonant TExx mode at position "x" along the cylinder doesn't move down the pipe, it's velocity is zero and it's frequency doesn't shift due to it's position. In a cone it does.
Todd

#### Rodal

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##### Re: EM Drive Developments - related to space flight applications - Thread 3
« Reply #2723 on: 06/26/2015 06:30 PM »

...I've also found a mechanism to boost the force many times over that of a photon rocket, such that this little bit of energy that escapes may in fact be enough to cause the observed thrust.

More when I finish the paper...
Todd

I would be interested to hear what component it could be that would multiply the thrust.  Would there be that much more radiation emitted?

When I've checked, rechecked, and validated my equations, I'll let you know. I ran a spreadsheet last night to determine the required stored energy for a given force. The numbers seem reasonable given the available data, "IFF" there were no plate on the big end and the flux could get out. With the big end sealed, the force is there, but it's cancelled at the big end. It's not going to do anything unless the flux can get out.

One of the key issues I've tried to answer is, what is the drift velocity of an Xnm mode in a tapered cylinder cavity? In a straight cylindrical cavity, a resonant TExx mode at position "x" along the cylinder doesn't move down the pipe, it's velocity is zero and it's frequency doesn't shift due to it's position. In a cone it does.
Todd

Please elaborate as to why you think that the velocity of a resonant TEmn is not zero, that it moves down, and that the frequency shifts.  Are you talking about phase shift due to geometrical attenuation?  And what do you mean by the TEmn moving down?

#### rfmwguy

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##### Re: EM Drive Developments - related to space flight applications - Thread 3
« Reply #2724 on: 06/26/2015 06:32 PM »

...I've also found a mechanism to boost the force many times over that of a photon rocket, such that this little bit of energy that escapes may in fact be enough to cause the observed thrust.

More when I finish the paper...
Todd

I would be interested to hear what component it could be that would multiply the thrust.  Would there be that much more radiation emitted?

When I've checked, rechecked, and validated my equations, I'll let you know. I ran a spreadsheet last night to determine the required stored energy for a given force. The numbers seem reasonable given the available data, "IFF" there were no plate on the big end and the flux could get out. With the big end sealed, the force is there, but it's cancelled at the big end. It's not going to do anything unless the flux can get out.

One of the key issues I've tried to answer is, what is the drift velocity of an Xnm mode in a tapered cylinder cavity? In a straight cylindrical cavity, a resonant TExx mode at position "x" along the cylinder doesn't move down the pipe, it's velocity is zero and it's frequency doesn't shift due to it's position. In a cone it does.
Todd

Strange you should say that, the circular gasket/insulator on the bottom of one of the early emdrive test articles in the UK has what appears to be a NON-conductive gasket, or perhaps partially conductive:

https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSPXOLt96QKQLkKeDssNd4R656gcbuL02UP0doK84LE8NSZgmU

This could be an area of flux egress. Not sure why its even needed unless the machining tolerances were so poor the fit couldn't be guananteed.

#### aero

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##### Re: EM Drive Developments - related to space flight applications - Thread 3
« Reply #2725 on: 06/26/2015 06:35 PM »
I don't recall whether or not I've posted this video, so here it is. I was fooling around back in April trying to create evanescent waves when I came across this very unusual pattern. I don't know that evanescent waves are involved at all but something unusual is showing up. You tell me?

Superluminal velocity? Well, strange things do happen.
Retired, working interesting problems

#### Rodal

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##### Re: EM Drive Developments - related to space flight applications - Thread 3
« Reply #2726 on: 06/26/2015 06:44 PM »
I don't recall whether or not I've posted this video, so here it is. I was fooling around back in April trying to create evanescent waves when I came across this very unusual pattern. I don't know that evanescent waves are involved at all but something unusual is showing up. You tell me?

Superluminal velocity? Well, strange things do happen.
Yes, in the acoustic analogue, this would be tantamount to shock waves due to exit speeds faster than the speed of sound.  The shock waves would look like that.

#### sghill

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##### Re: EM Drive Developments - related to space flight applications - Thread 3
« Reply #2727 on: 06/26/2015 06:47 PM »
The only way these things will work is to interact with an outside environment. I believe I've figured out that this mechanism is the finite conductivity of copper + heat, allowing voltage drop to form on the conductor, AKA "Ohm's Law". Where there is voltage and current there are volt-seconds, or magnetic flux that is passing through that open window. So heat and poor conductivity allow flux to escape (tunnel) through the copper.

So, with the increased wall thickness of the baby EMDrive with respect to the cone size and power input, should we expect no meaningfully significant thrust measurements, or is the copper "transparent" to the tunneling flux?

P.S.  A corollary thought is: if the material matters (it interacts) with respect to the flux escape, then should SeeShells' copper mesh EMDrive show increased performance in with respect to cone size and power input compared with a sheet copper EMDrive?
« Last Edit: 06/26/2015 07:13 PM by sghill »
Bring the thunder Elon!

#### rfmwguy

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##### Re: EM Drive Developments - related to space flight applications - Thread 3
« Reply #2728 on: 06/26/2015 06:47 PM »
I don't recall whether or not I've posted this video, so here it is. I was fooling around back in April trying to create evanescent waves when I came across this very unusual pattern. I don't know that evanescent waves are involved at all but something unusual is showing up. You tell me?

Superluminal velocity? Well, strange things do happen.
Before you posted this, I was imagining a gasket material (O-ring) that "insulated" the big diameter plate from the inner wall of the frustum. Thought experiment was backwards flux flow very similar to the 2D movie you presented.

Trick here would be storage and release of magnetic flux...hold on...flux capacitor...I think I just shot myself in the foot.

#### Rodal

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##### Re: EM Drive Developments - related to space flight applications - Thread 3
« Reply #2729 on: 06/26/2015 06:54 PM »
I don't recall whether or not I've posted this video, so here it is. I was fooling around back in April trying to create evanescent waves when I came across this very unusual pattern. I don't know that evanescent waves are involved at all but something unusual is showing up. You tell me?

Superluminal velocity? Well, strange things do happen.
Before you posted this, I was imagining a gasket material (O-ring) that "insulated" the big diameter plate from the inner wall of the frustum. Thought experiment was backwards flux flow very similar to the 2D movie you presented.

Trick here would be storage and release of magnetic flux...hold on...flux capacitor...I think I just shot myself in the foot.
Looking forward to what Martin Tajmar is going to present regarding "side effects" of EM Drive measurements

#### sghill

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##### Re: EM Drive Developments - related to space flight applications - Thread 3
« Reply #2730 on: 06/26/2015 06:57 PM »
Quote

While I enjoyed Mr Ts infectious enthusiasm, many posts were repeats and reminded me of advocacy posts. There is a growing marketing industry out there that pays people for position statements on social media; sponsored advertising in the 21st century if you will. Not saying Mr T is one, but posters should avoid these traps...it is transparent to many. And yes, nicknames are fine but real names on formal papers is a must.

Not just a "new paper" was promised but what was much more outlandish (and completely unneeded), it was claimed that the paper was going to appear in a "peer-reviewed journal" (apparently addressing the poster's self-perceived problem that none of Shawyer's prior publications ever appeared in peer-reviewed journals), that the paper "was under peer-review", and that, upon having the rare privilege of being able to read the paper before publication (a privilege that people usually keep in confidence and never disclose in a public forum), it was (again, without any need) claimed that the paper would "end all doubt" about the EM Drive.

Perhaps @TheTraveller is really Andrea Rossi!  Certainly sounds like him....
Bring the thunder Elon!

#### rfmwguy

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##### Re: EM Drive Developments - related to space flight applications - Thread 3
« Reply #2731 on: 06/26/2015 07:03 PM »
I don't recall whether or not I've posted this video, so here it is. I was fooling around back in April trying to create evanescent waves when I came across this very unusual pattern. I don't know that evanescent waves are involved at all but something unusual is showing up. You tell me?

Superluminal velocity? Well, strange things do happen.
Before you posted this, I was imagining a gasket material (O-ring) that "insulated" the big diameter plate from the inner wall of the frustum. Thought experiment was backwards flux flow very similar to the 2D movie you presented.

Trick here would be storage and release of magnetic flux...hold on...flux capacitor...I think I just shot myself in the foot.
Looking forward to what Martin Tajmar is going to present regarding "side effects" of EM Drive measurements
This is certainly a big surprise. Lets hope its not about safe handling and exposure to high voltages and currents in bias/supply wires...worse yet, some theoretical causality between emdrive leakage and climate change...Yep, will be looking forward to that vid stream.

#### SeeShells

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##### Re: EM Drive Developments - related to space flight applications - Thread 3
« Reply #2732 on: 06/26/2015 07:22 PM »
The only way these things will work is to interact with an outside environment. I believe I've figured out that this mechanism is the finite conductivity of copper + heat, allowing voltage drop to form on the conductor, AKA "Ohm's Law". Where there is voltage and current there are volt-seconds, or magnetic flux that is passing through that open window. So heat and poor conductivity allow flux to escape (tunnel) through the copper.

So, with the increased wall thickness of the baby EMDrive with respect to the cone size and power input, should we expect no meaningfully significant thrust measurements, or is the copper "transparent" to the tunneling flux?

P.S.  A corollary thought is: if the material matters to the flux escape, then should SeaShells' copper mesh EMDrive show increased performance in with respect to cone size and power input?
Was out in my highly envied "shop" today and haven't been able to follow post to post and I'll catch up to where I left off reading in a bit. You're right in thinking I feel that the copper has the magic squirrel sauce that makes it work and one reason I shelved the other two (for now) designs to push on the perforated copper design and testing.

One time I had access to a very sharp staff and we were contemplating on using "light Tweezers" to move very small gold wires on a semiconductor chip, it was a viable project, but because of things that were not related to "it's not a good idea" it had to be shelved.

The things that intrigued us was the ability of an evanescent wave to manipulate an object, a wave that couldn't carry information or couldn't do work with it, hmmmm, it seemed to do. It still does intrigue me and I believe it can be a clue of why this cavity works the way it does.
Nice clue, thanks Dr. Rodal!
http://arxiv.org/ftp/arxiv/papers/1308/1308.0547.pdf

I'm still digging into it and I know they are much smarter people here than me that have a more detailed knowledge in depth and breadth and right now I'm trying to be a one girl band and finding it hard.

Love for you all to beat this idea up and kick it around. I think the evanescent waves due to their extraordinary nature and spooky weird actions can impart a directional momentum and thrust to the EMdrive.

Back to reading a little and then into my playground.

Shell

#### Devilstower

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##### Re: EM Drive Developments - related to space flight applications - Thread 3
« Reply #2733 on: 06/26/2015 07:29 PM »
In the future, "Section Four" will have the same resonance as "Area 51."

#### hhexo

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##### Re: EM Drive Developments - related to space flight applications - Thread 3
« Reply #2734 on: 06/26/2015 07:32 PM »
It strikes me that a string with variable thickness is easier to manufacture and much safer to use than DIY cavities and magnetrons...

Proposal for an acoustic (imperfect) analogue of the EmDrive
(defined as "an acoustic system storing energy in standing waves and with a variable refraction index along an axis")

0. The basic idea is to take a string manufactured with a thickness following a linear gradient, and excite it until it resonates.

1. How do we manufacture a string with variable thickness?
- Take a steel E or B guitar string (non-wound) and set it on something that keeps it straight.
- Take a spray can of transparent paint (the one used for fixing artwork).
- Repeat:
--- Spray the string with paint from start to end, but increasing traversal speed as you do so.
--- Rotate the string slightly.
After enough spraying, you'll get a thicker coating of paint on one side due to the gradient in the speed of spraying.

2. One string doesn't store much energy, how do we optimize the setup to get more energy?
Have a lot of strings, arranged parallel to each other in an array, with the same orientation.
(this should be equivalent to a lot of EmDrives parallel to each other)

3. How do we excite the strings?
Blast white noise at them (the analogue of a magnetron?).
Alternatively use magnetic fields, i.e. the inverse of what electric guitar pickups do.

4. How do we NOT get lynched by an angry mob of neighbours due to all the noise?
Do the experiments in an abandoned airfield or the desert.

SAFETY ADVICE: Wear noise-cancelling headphones. In order to get a few Watts into the strings, you will produce a lot of noise.

I don't know if an acoustic analogue of the EmDrive would move... but it would rock!

#### mrwiffler

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##### Re: EM Drive Developments - related to space flight applications - Thread 3
« Reply #2735 on: 06/26/2015 07:38 PM »
Quote from hhexo:
Quote
. How do we excite the strings?

http://www.ebow.com/home.php
« Last Edit: 06/26/2015 07:40 PM by mrwiffler »

#### Devilstower

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##### Re: EM Drive Developments - related to space flight applications - Thread 3
« Reply #2736 on: 06/26/2015 07:40 PM »
Apologies. My Area 52 = Section 4 remark was concerning the JANNAF conference in which Section IV covered propellentless systems. Not only did I make a weak joke, I made poor assumptions about how quotes worked within the forum.

#### hhexo

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##### Re: EM Drive Developments - related to space flight applications - Thread 3
« Reply #2737 on: 06/26/2015 07:40 PM »
Quote
. How do we excite the strings?

http://www.ebow.com/home.php

Yes!
I think that is exactly an implementation of what I was saying with "Alternatively use magnetic fields, i.e. the inverse of what electric guitar pickups do."

#### Rodal

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##### Re: EM Drive Developments - related to space flight applications - Thread 3
« Reply #2738 on: 06/26/2015 07:46 PM »
It strikes me that a string with variable thickness is easier to manufacture and much safer to use than DIY cavities and magnetrons...

Proposal for an acoustic (imperfect) analogue of the EmDrive
(defined as "an acoustic system storing energy in standing waves and with a variable refraction index along an axis")

0. The basic idea is to take a string manufactured with a thickness following a linear gradient, and excite it until it resonates.

1. How do we manufacture a string with variable thickness?
- Take a steel E or B guitar string (non-wound) and set it on something that keeps it straight.
- Take a spray can of transparent paint (the one used for fixing artwork).
- Repeat:
--- Spray the string with paint from start to end, but increasing traversal speed as you do so.
--- Rotate the string slightly.
After enough spraying, you'll get a thicker coating of paint on one side due to the gradient in the speed of spraying.

2. One string doesn't store much energy, how do we optimize the setup to get more energy?
Have a lot of strings, arranged parallel to each other in an array, with the same orientation.
(this should be equivalent to a lot of EmDrives parallel to each other)

3. How do we excite the strings?
Blast white noise at them (the analogue of a magnetron?).
Alternatively use magnetic fields, i.e. the inverse of what electric guitar pickups do.

4. How do we NOT get lynched by an angry mob of neighbours due to all the noise?
Do the experiments in an abandoned airfield or the desert.

SAFETY ADVICE: Wear noise-cancelling headphones. In order to get a few Watts into the strings, you will produce a lot of noise.

I don't know if an acoustic analogue of the EmDrive would move... but it would rock!

Wouln't the acoustic propulsion (hat tip to Prof Uno Ingard at MIT) of a tapered bottle be a better acoustic analogue to the EM Drive than a string?

#### rfmwguy

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##### Re: EM Drive Developments - related to space flight applications - Thread 3
« Reply #2739 on: 06/26/2015 07:57 PM »
Apologies. My Area 52 = Section 4 remark was concerning the JANNAF conference in which Section IV covered propellentless systems. Not only did I make a weak joke, I made poor assumptions about how quotes worked within the forum.
Just click the Quote button and post away...I was wondering what it refered to...as it is now, not a bad joke, I've made worse.

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