Author Topic: EM Drive Developments - related to space flight applications - Thread 2  (Read 2101136 times)

Offline phaseshift

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A thought experiment:

Many physicists postulate that we live in a 3+1 deSitter space, and specifically I refer to Lisa Randall, Raman Sundrum http://arxiv.org/abs/hep-ph/9905221.  Briefly they claim an additional finite dimension between our brane (weak/Tev) and a gravity brane (strong) where gravity actually exists.  The distance between these branes is the reason that gravity is such a comparatively weak force.  The length of this 4th spacial dimension has an upper limit of somewhat less than 1 millimeter (otherwise we would have seen its effects long ago). The force of gravity on the gravity brane is expected to be 16 orders of magnitude greater than it is on our brane.

Is it possible that RF energy, specifically microwaves, is able to inflate this 4th dimension causing the gravity brane to be farther from our brane and thus weakening the gravitation force, effectively warping space, or warping it less than it usually is. Light passing through such a region would be blue shifted, or to put it another way gravitational redshifting would be lessened. I'll call this localized volume of warped space a warp field for my thought experiment.

Such an effect would not produce thrust. However, it would magnify thrust from another source (increased entropy).

To take this thought experiment a little farther.  IF the RF energy inflates this finite dimension then it is open to longer wavelength RF energy. The shorter wavelengths are in effect prying open the dimension and then by using longer wavelengths it can be further inflated.

Where in the frustrum is this possibly taking place? In the cavity proper itself, at the small end plate, large end plate, or perhaps at each end plate? If it is occurring at each end plate then there are two warp fields , each with possibly a different magnitude. How large are the fields and do they overlap? Can the presence of two warp fields with different magnitudes produce thrust?

My math skills are not adequate to pursue this, 1st year Calculus 35 years ago is a distant memory.
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Offline txdrive

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Ultimately what Shawyer's and White's theories amount to, is that there is a radiation pressure imbalance on the inside of the cavity, resulting in a net force, which is a non small fraction of the total radiation pressure on the inside of the cavity (more than 1%). Shawyer says it is in accordance with Maxwell's equations, which is flat out wrong.

Where is Shawyer wrong?

1) Is the cutoff wavelength different at the small and big ends or not?

2) Is the guide wavelength different at the small and big ends or not?

3) Is the group velocity different at the small and big ends or not?

4) Is the bounce force different at the small and big ends or not?

5) Is the bounce force at the big end greater than at the small end or not?

6) Is there a bounce force on the side walls or not?

Just trying to understand where you believe Shawyer is wrong?
Well, firstly, Shawyer has greater radiation pressure upon the wide end, but his drive is pushing narrow end forwards.

Secondarily, yes, there is an interaction between the EM field and the walls, which results in a force on the side walls, equal to change in momentum of the EM field travelling down it, per time.

Maxwell has a cosine factor to adjust for waves that hit the bounce surface at an angle. Max force at the end plates and min force at the walls as attached.
Nope. Maxwell's equations are field equations and have nothing about waves hitting anything at an angle. They also work for a solenoid plugged into your household AC.
Quote

CofM requires if the EM waves pushes more on the on the big end than the small end, the EM Drive frustum pushes back in the opposite direction of the imbalance. Momentum transfer is not one sided. If the EM Drive moved toward the big end, then CofE would be violated as only a one sided push.

I think you're confused with regards to how forces and reaction works...

Let's say we got a real actual pressure imbalance, for example, by putting a flashlight inside the cavity, pointed at the wide end (which is not perfectly reflective). The flashlight itself is magnetically levitated from outside the cavity, so it stays in place. This will cause more radiation pressure upon the wide end, which will make it move wide end forward (with the same force as the force propelling the flashlight as a photon rocket, but in opposite direction). If held in place, the frustum will be applying two forces: one on the radiation, wide end to narrow end, other on the mounts, narrow end to the wide end (as when pushing wide end forward).

With regards to the alleged agreement between experiments and theory, EagleWorks did also report "agreement" somehow in spite of the fact that the theory predicts that you should have the same thrust when you turn your drive around 180 degrees, and they don't.
« Last Edit: 05/19/2015 06:56 PM by txdrive »

Offline squid

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Both Shawyer & the Chinese claim their many physical devices produce thrust and the measurement of that thrust is in agreement with their theoretical calculations. Both also claim no new physics is needed and CofE / CofM are conserved.

I mean you say it can't work as they claim, yet it does and the measured thrust from many devices, measured in different ways, in different labs, in different countries all closely matched what their theory says the thrust should be.

With respect, just maybe your explanation / understanding of what is happening inside the frustum is not at the same level as Shawyer or the Chinese?

Or perhaps they are all making basic mistakes in their sloppy experimental setups, pumping kW of microwave power into poorly shielded cavities and reporting thrusts near their error limits?

This is all standard physics, supported by a century of experiments all conducted with far more precision and rigor than anything published on the EM drive.

Incidentally, after doing a brief literature search, I have attached an experiment performed in the early 90's on a superconducting frustrum cavity, with a Q of at least 20,000. The paper is nice in that it gives explicit formulae for the EM fields in such a cavity. Their classical model fits the data perfectly. I might also note that they didn't see the thing shoot out of their dewar...

Offline SeeShells

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We could pull it behind my 65 Pontiac Catalina. :) NASA has already proven that a 421 powered Pontiac will make things fly.

http://www.dfrc.nasa.gov/Gallery/Movie/M2-F1/HTML/EM-0020-02.html
I thought my brain was being warped at the Super Conductor Super Collider, but this is a lot of fun. Love the pool of thoughts and ideas here it keeps me young and thinking. 
If you use solid copper sheeting for the body of the EM device and that seems to be because of it's thermal and electrical conductivity, couldn't you use a different extruded metal? Extruded Brass comes to mind, 90% copper and 10% tin. Or steel? Unless someone can provide me with as reason why I should just use copper sheeting. Yes, I'm thinking about building one too. I have a 2500 sq ft shop with all kind of toys for metal and electronics left over from my business. I'm not the kind to just throw it together and there is a lot of research yet to be done. And there will be shielding!

Offline TheTraveller


We could pull it behind my 65 Pontiac Catalina. :) NASA has already proven that a 421 powered Pontiac will make things fly.

http://www.dfrc.nasa.gov/Gallery/Movie/M2-F1/HTML/EM-0020-02.html
I thought my brain was being warped at the Super Conductor Super Collider, but this is a lot of fun. Love the pool of thoughts and ideas here it keeps me young and thinking. 
If you use solid copper sheeting for the body of the EM device and that seems to be because of it's thermal and electrical conductivity, couldn't you use a different extruded metal? Extruded Brass comes to mind, 90% copper and 10% tin. Or steel? Unless someone can provide me with as reason why I should just use copper sheeting. Yes, I'm thinking about building one too. I have a 2500 sq ft shop with all kind of toys for metal and electronics left over from my business. I'm not the kind to just throw it together and there is a lot of research yet to be done. And there will be shielding!

Shawyer's 1st maggie powered test unit, Faraday Cage and the balance beam system. Not rocket science. Max thrust was 16mN at 850W input. Not much but with care, measurable.

http://emdrive.com/feasibilitystudy.html
« Last Edit: 05/19/2015 07:14 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 phaseshift

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If you use solid copper sheeting for the body of the EM device and that seems to be because of it's thermal and electrical conductivity, couldn't you use a different extruded metal? Extruded Brass comes to mind, 90% copper and 10% tin. Or steel? Unless someone can provide me with as reason why I should just use copper sheeting. Yes, I'm thinking about building one too.

I think weight is a consideration, so I've crossed off steel.  Also copper can not be anodized with silver, though there may be other techniques that can plate it.  Silver will raise the Q factor as I understand it.  A copper/aluminum alloy can be anodized with silver, as can aluminum itself.

For these reasons I've settled on aluminum until I find reason to pick something else.

Also 3D printing allows for additional weight savings, some of the parts can have internal cavities.  3D printing can be done at a resolution of 20 microns.
"It doesn't have to be a brain storm, a drizzle will often do" - phaseshift

Offline TheTraveller


Both Shawyer & the Chinese claim their many physical devices produce thrust and the measurement of that thrust is in agreement with their theoretical calculations. Both also claim no new physics is needed and CofE / CofM are conserved.

I mean you say it can't work as they claim, yet it does and the measured thrust from many devices, measured in different ways, in different labs, in different countries all closely matched what their theory says the thrust should be.

With respect, just maybe your explanation / understanding of what is happening inside the frustum is not at the same level as Shawyer or the Chinese?

Or perhaps they are all making basic mistakes in their sloppy experimental setups, pumping kW of microwave power into poorly shielded cavities and reporting thrusts near their error limits?

This is all standard physics, supported by a century of experiments all conducted with far more precision and rigor than anything published on the EM drive.

Incidentally, after doing a brief literature search, I have attached an experiment performed in the early 90's on a superconducting frustrum cavity, with a Q of at least 20,000. The paper is nice in that it gives explicit formulae for the EM fields in such a cavity. Their classical model fits the data perfectly. I might also note that they didn't see the thing shoot out of their dewar...

Guess you have not read the Chinese data:

http://www.emdrive.com/NWPU2010translation.pdf
http://www.emdrive.com/NWPU2010testresults.pdf
http://www.emdrive.com/yang-juan-paper-2012.pdf

The thrust measured was not the EagleWorks mosquito landing on your arm level. Maybe read the papers before claiming

Quote
Or perhaps they are all making basic mistakes in their sloppy experimental setups, pumping kW of microwave power into poorly shielded cavities and reporting thrusts near their error limits?

as a quick way to dismiss their results.
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.
Herman Melville, Moby Dick

Offline SeeShells

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If you use solid copper sheeting for the body of the EM device and that seems to be because of it's thermal and electrical conductivity, couldn't you use a different extruded metal? Extruded Brass comes to mind, 90% copper and 10% tin. Or steel? Unless someone can provide me with as reason why I should just use copper sheeting. Yes, I'm thinking about building one too.

I think weight is a consideration, so I've crossed off steel.  Also copper can not be anodized with silver, though there may be other techniques that can plate it.  Silver will raise the Q factor as I understand it.  A copper/aluminum alloy can be anodized with silver, as can aluminum itself.

For these reasons I've settled on aluminum until I find reason to pick something else.

Also 3D printing allows for additional weight savings, some of the parts can have internal cavities.  3D printing can be done at a resolution of 20 microns.
20 microns is 0.0008 of an inch and quite impressive (I built and designed XYZand T semiconductor machines with an positional accuracy of .25 um across 300mm) Is the price dropped low enough vs the real advantages of just using digital micrometers and good machining practices? To me nothing is really set in stone in the cavity designs and it seems like every day some new revelation pops up. Has 3D printing (with metals or conductors) dropped that low? I at least want to built it somewhat modular and that can allow design changes.

Offline phaseshift

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A thought experiment:

Many physicists postulate that we live in a 3+1 deSitter space, and specifically I refer to Lisa Randall, Raman Sundrum http://arxiv.org/abs/hep-ph/9905221.  Briefly they claim an additional finite dimension between our brane (weak/Tev) and a gravity brane (strong) where gravity actually exists.  The distance between these branes is the reason that gravity is such a comparatively weak force.  The length of this 4th spacial dimension has an upper limit of somewhat less than 1 millimeter (otherwise we would have seen its effects long ago). The force of gravity on the gravity brane is expected to be 16 orders of magnitude greater than it is on our brane....

For whatever it's worth, a short note that Dr. White and Paul March both have invoked a (4+1) brane of spacetime in their explanation and papers.

Yes, I noticed that. Though I didn't follow why they did so, it seemed disconnected to me. I thought they referred to a 3+1 space, but if they used 4+1 then they included time. I'm more inclined to use 3+1 and set time aside.
"It doesn't have to be a brain storm, a drizzle will often do" - phaseshift

Offline LasJayhawk



If you use solid copper sheeting for the body of the EM device and that seems to be because of it's thermal and electrical conductivity, couldn't you use a different extruded metal? Extruded Brass comes to mind, 90% copper and 10% tin. Or steel? Unless someone can provide me with as reason why I should just use copper sheeting. Yes, I'm thinking about building one too.

I think weight is a consideration, so I've crossed off steel.  Also copper can not be anodized with silver, though there may be other techniques that can plate it.  Silver will raise the Q factor as I understand it.  A copper/aluminum alloy can be anodized with silver, as can aluminum itself.

For these reasons I've settled on aluminum until I find reason to pick something else.

Also 3D printing allows for additional weight savings, some of the parts can have internal cavities.  3D printing can be done at a resolution of 20 microns.

Both brass and copper take to electroplating with silver nicely and would provide a higher Q than bare copper.


Keep in mind that any metal can be plated with the right combination. A chrome car bumper was steel, plated with copper, plated with nickel, plated with chrome, the nickel won't plate  very well directly to steel...

Offline phaseshift

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If you use solid copper sheeting for the body of the EM device and that seems to be because of it's thermal and electrical conductivity, couldn't you use a different extruded metal? Extruded Brass comes to mind, 90% copper and 10% tin. Or steel? Unless someone can provide me with as reason why I should just use copper sheeting. Yes, I'm thinking about building one too.

I think weight is a consideration, so I've crossed off steel.  Also copper can not be anodized with silver, though there may be other techniques that can plate it.  Silver will raise the Q factor as I understand it.  A copper/aluminum alloy can be anodized with silver, as can aluminum itself.

For these reasons I've settled on aluminum until I find reason to pick something else.

Also 3D printing allows for additional weight savings, some of the parts can have internal cavities.  3D printing can be done at a resolution of 20 microns.
20 microns is 0.0008 of an inch and quite impressive (I built and designed XYZand T semiconductor machines with an positional accuracy of .25 um across 300mm) Is the price dropped low enough vs the real advantages of just using digital micrometers and good machining practices? To me nothing is really set in stone in the cavity designs and it seems like every day some new revelation pops up. Has 3D printing (with metals or conductors) dropped that low? I at least want to built it somewhat modular and that can allow design changes.

One off prices are still pretty high, though you can pick your resolution, lower res, lower cost. 20 microns is probably way more precise than needed.  The lower the res the shorter the print time and therefore the cost. The reason I'm looking at 3D printing is that I don't know how to machine a spherically concave surface. I've polished glass plates for telescope mirrors, but that's not helpful ;)  I'm not a machinist and it may actually be easy - but considering there is a local fablab I am happy to pay for a one off and not be bothered with having to figure out how to machine it.
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Offline rfcavity

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Both Shawyer & the Chinese claim their many physical devices produce thrust and the measurement of that thrust is in agreement with their theoretical calculations. Both also claim no new physics is needed and CofE / CofM are conserved.

I mean you say it can't work as they claim, yet it does and the measured thrust from many devices, measured in different ways, in different labs, in different countries all closely matched what their theory says the thrust should be.

With respect, just maybe your explanation / understanding of what is happening inside the frustum is not at the same level as Shawyer or the Chinese?

Or perhaps they are all making basic mistakes in their sloppy experimental setups, pumping kW of microwave power into poorly shielded cavities and reporting thrusts near their error limits?

This is all standard physics, supported by a century of experiments all conducted with far more precision and rigor than anything published on the EM drive.

Incidentally, after doing a brief literature search, I have attached an experiment performed in the early 90's on a superconducting frustrum cavity, with a Q of at least 20,000. The paper is nice in that it gives explicit formulae for the EM fields in such a cavity. Their classical model fits the data perfectly. I might also note that they didn't see the thing shoot out of their dewar...

Guess you have not read the Chinese data:

http://www.emdrive.com/NWPU2010translation.pdf
http://www.emdrive.com/NWPU2010testresults.pdf
http://www.emdrive.com/yang-juan-paper-2012.pdf

The thrust measured was not the EagleWorks mosquito landing on your arm level. Maybe read the papers before claiming

Quote
Or perhaps they are all making basic mistakes in their sloppy experimental setups, pumping kW of microwave power into poorly shielded cavities and reporting thrusts near their error limits?

as a quick way to dismiss their results.

A.single paper is not a magic wand which causes all previous results to disappear. It cannot chan ge the tens of thousands of previous measure ments that have taken place in the last 50years. How do you refute cavities in pillbox shape that are used in GPS satellite atomic clocks? These have been characterized down to sub nanowatt levels, and no mystery power draw is observed and no thrust is observed in the GPS satellites (the location of which must be known very well.)

Offline deltaMass

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About building your own cavity - it would be helpful to know how this is supposed to scale with frequency. Since known physics predicts that the device doesn't work, that scaling law is not to hand. Otherwise, one might have a reason to build a light frequency device that fits in your hand. But one doesn't know. So, as TheTraveller points out, the only reasonable thing to do is a replication of an apparatus that is claimed to produce thrust. So either Shawyer's or Juan's.

Offline phaseshift

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If you use solid copper sheeting for the body of the EM device and that seems to be because of it's thermal and electrical conductivity, couldn't you use a different extruded metal? Extruded Brass comes to mind, 90% copper and 10% tin. Or steel? Unless someone can provide me with as reason why I should just use copper sheeting. Yes, I'm thinking about building one too.

I think weight is a consideration, so I've crossed off steel.  Also copper can not be anodized with silver, though there may be other techniques that can plate it.  Silver will raise the Q factor as I understand it.  A copper/aluminum alloy can be anodized with silver, as can aluminum itself.

For these reasons I've settled on aluminum until I find reason to pick something else.

Also 3D printing allows for additional weight savings, some of the parts can have internal cavities.  3D printing can be done at a resolution of 20 microns.

Both brass and copper take to electroplating with silver nicely and would provide a higher Q than bare copper.


Keep in mind that any metal can be plated with the right combination. A chrome car bumper was steel, plated with copper, plated with nickel, plated with chrome, the nickel won't plate  very well directly to steel...

Yes, electroplating is the way to go (there is so much to learn here) - aluminum still seems the best choice for its lower weight.  I see that copper can also be 3D printed: http://3dprint.com/59881/nasa-3d-prints-copper-rocket/.
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Offline SeeShells

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A thought experiment:

Many physicists postulate that we live in a 3+1 deSitter space, and specifically I refer to Lisa Randall, Raman Sundrum http://arxiv.org/abs/hep-ph/9905221

I have Warped Passages by Lisa Randall, I need to get it out and re-read it, she is one of my heroes and if I believe (need to look again) she finds quasicrystals might have an underlying structure into other dimensions. Whoa! Ok need to sit in my hot tub and think some.

Offline phaseshift

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A thought experiment:

Many physicists postulate that we live in a 3+1 deSitter space, and specifically I refer to Lisa Randall, Raman Sundrum http://arxiv.org/abs/hep-ph/9905221

I have Warped Passages by Lisa Randall, I need to get it out and re-read it, she is one of my heroes and if I believe (need to look again) she finds quasicrystals might have an underlying structure into other dimensions. Whoa! Ok need to sit in my hot tub and think some.

I have all of her books (4 I think, or is it 3?).  In Warped Passages I swear I remember her mentioning the possibility of inflating the 4sd (4th spatial dimension) - though there was no known mechanism.  Just like there is no known physical mechanism for the  inflationary period of the Universe.
"It doesn't have to be a brain storm, a drizzle will often do" - phaseshift

Offline TheTraveller

Both of the SPR Flight Thrusters, build under contract with Boeing, may have been built from existing microwave horn antenna stock.

Compare the 1st attachment and this rectangular horn antenna:
http://www.pasternack.com/standard-gain-horn-waveguide-size-wr159-10-db-gain-sma-female-pe9860sf-10-p.aspx

Have also found circular horn antenna that may be close. Still looking. If I can find a stock cone horn antenna that closely fits the dimensions, we may be able to get the exact internal dimensions.
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.
Herman Melville, Moby Dick

Offline LasJayhawk



If you use solid copper sheeting for the body of the EM device and that seems to be because of it's thermal and electrical conductivity, couldn't you use a different extruded metal? Extruded Brass comes to mind, 90% copper and 10% tin. Or steel? Unless someone can provide me with as reason why I should just use copper sheeting. Yes, I'm thinking about building one too.

I think weight is a consideration, so I've crossed off steel.  Also copper can not be anodized with silver, though there may be other techniques that can plate it.  Silver will raise the Q factor as I understand it.  A copper/aluminum alloy can be anodized with silver, as can aluminum itself.

For these reasons I've settled on aluminum until I find reason to pick something else.

Also 3D printing allows for additional weight savings, some of the parts can have internal cavities.  3D printing can be done at a resolution of 20 microns.

Both brass and copper take to electroplating with silver nicely and would provide a higher Q than bare copper.


Keep in mind that any metal can be plated with the right combination. A chrome car bumper was steel, plated with copper, plated with nickel, plated with chrome, the nickel won't plate  very well directly to steel...

Yes, electroplating is the way to go (there is so much to learn here) - aluminum still seems the best choice for its lower weight.  I see that copper can also be 3D printed: http://3dprint.com/59881/nasa-3d-prints-copper-rocket/.

You can plate aluminum with copper or nickel then silver plate. I think there are some tricks (read extra steps) to get the first plate to stick to the aluminum base.

Offline Stormbringer

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How about extrapolating/interpolating downward by calculating dimensions from resonant frequencies of these test articles? Use that interpolation to select a smaller sized set of cavity dimensions and scale up the frequencies to get that thrust signal out of the "iffy" zone?
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Offline deltaMass

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How about extrapolating/interpolating downward by calculating dimensions from resonant frequencies of these test articles? Use that interpolation to select a smaller sized set of cavity dimensions and scale up the frequencies to get that thrust signal out of the "iffy" zone?
The point I was making was that we don't know whether or not higher frequencies produce higher thrust. That's unless you happen to know.

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