Author Topic: EM Drive Developments Thread 1  (Read 797038 times)

Offline IslandPlaya

  • Full Member
  • ****
  • Posts: 582
  • Outer Hebrides
  • Liked: 163
  • Likes Given: 166
Re: EM Drive Developments
« Reply #560 on: 09/15/2014 12:04 AM »
As someone said before and in agreement on the experimentalist side of things...
Why doesn't someone get a bloody big 100Kw setup of the devices discussed and measure thrust?
We wouldn't need vacuum chambers or any nonsense.
Why not?

Do we need to go to 100kW ? Does the Shawyer/SPR Ltd.'s device have a thrust orders of magnitude (400 to 4250 times higher) higher than Cannae device -as quoted by Dr. White- yes or not?
Ok, start at 1KW then 10KW then 100KW...
The point is its much easier (I think) to construct higher power devices than to detect low thrust levels.
If a 1KW device was to slide down an air-track then the world would change...

Offline Rodal

  • Senior Member
  • *****
  • Posts: 5895
  • USA
  • Liked: 6045
  • Likes Given: 5325
Re: EM Drive Developments
« Reply #561 on: 09/15/2014 12:06 AM »
As someone said before and in agreement on the experimentalist side of things...
Why doesn't someone get a bloody big 100Kw setup of the devices discussed and measure thrust?
We wouldn't need vacuum chambers or any nonsense.
Why not?

Do we need to go to 100kW ? Does the Shawyer/SPR Ltd.'s device have a thrust orders of magnitude (400 to 4250 times higher) higher than Cannae device -as quoted by Dr. White- yes or not?
Ok, start at 1KW then 10KW then 100KW...
The point is its much easier (I think) to construct higher power devices than to detect low thrust levels.
If a 1KW device was to slide down an air-track then the world would change...

OK I completely agree with you and JohnFornaro on that.  Now,

Does the Shawyer/SPR Ltd.'s device have a thrust orders of magnitude (400 to 4250 times higher) higher than Cannae device -as quoted by Dr. White- yes or not?  Did Dr. White's lab test the Shawyer/SPR Ltd.'s device, yes or not?

Can someone in this forum answer that, please  :)?
« Last Edit: 09/15/2014 12:07 AM by Rodal »

Offline IslandPlaya

  • Full Member
  • ****
  • Posts: 582
  • Outer Hebrides
  • Liked: 163
  • Likes Given: 166
Re: EM Drive Developments
« Reply #562 on: 09/15/2014 12:07 AM »
I don't know
and
I don't know

Offline ThinkerX

  • Full Member
  • ***
  • Posts: 311
  • Alaska
  • Liked: 120
  • Likes Given: 59
Re: EM Drive Developments
« Reply #563 on: 09/15/2014 12:09 AM »
Quote
an interesting paper by Dr. White.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf

In particular, I find the Math toward the end of the slide show  interesting.

I ran through the slideshow a couple times.  (Am I to interpret the first part as meaning that actual, successful, 'bench-top' warp field experiments have already been conducted?)

The 'mission calculations' for Q-Thruster spacecraft were interesting.  Proxima Centauri in under 30 years?  (Which might also mean a very roughly time to reach Tau Ceti or some such - longer period for acceleration.)

The math in the last section defeated my feeble skills in short order.  The notion of gravity as emergent from vacuum energy, rather than fundamental in and of itself is something I have not come across before.  Wouldn't this have implications for relativity?  Again, the math beat me.

As too...

Quote
THRUST FORCE: 400 to 4250 times higher for Shawyer/SPR Ltd.'s device than for Cannae's device
SPECIFIC FORCE  ( Thrust Force / Input Electric Power) : 14 to 286 times higher for Shawyer/SPR Ltd.'s device than for Cannae's device

1) Would you consider the Shawyer/SPR Ltd.'s device a "scaled-up" version of the Cannae device -last tested at NASA Eagleworks as per the "Anomalous thrust ..." paper-?

or

2) Are the numbers quoted by Dr. White for Shawyer/SPR Ltd.'s device  unrepresentative because of A) some mistake I made in my interpretation or B) because Dr. White did NOT test  Shawyer/SPR Ltd.'s device and the numbers he quoted were measured elsewhere?

Something crucial is missing here.  We have independent (?) groups building mechanisms based on different theories (?), all of which apparently produce positive results (?) of differing magnitudes.   Yet, at best it takes...uncomfortable assumptions... to make these results square with existing theory.   Two thoughts:

First, 'Plato's Cave:' imagine a group of people confined in a large dim room, which so far as they know is the sum total of the universe.  Flickering lights make shadow images on the wall, from which they deduce, or attempt to deduce how their world functions.  Their interpretation of these images becomes quite sophisticated, yet the images remain just that: an image of reality rather than reality itself.    At the Quantum or Dark Energy level, something similar may be in effect here - the theories and models used describe what is *apparently* happening, rather than what is *actually* happening, and worse our innate limitations are such we can't go from one to the other.    The models and theories will always be flawed, and this flaw somehow accounts for (part?) of the differing test results.   (apologies for the horribly botched explanation of Plato's Cave.)

Second thought...been a long, long time since I did any reading on it, as it was considered far fetched fringe material way back in the 70's and 80's...but wasn't there a fellow named Townsend Brown mucking around with something vaguely similar to 'Q-Thrusters' forty or fifty years ago?  Seem to remember the UFO types (apologies again) were all over his work.

Offline Rodal

  • Senior Member
  • *****
  • Posts: 5895
  • USA
  • Liked: 6045
  • Likes Given: 5325
Re: EM Drive Developments
« Reply #564 on: 09/15/2014 12:11 AM »
I don't know
and
I don't know

Thank you

and

Thank you

Offline IslandPlaya

  • Full Member
  • ****
  • Posts: 582
  • Outer Hebrides
  • Liked: 163
  • Likes Given: 166
Re: EM Drive Developments
« Reply #565 on: 09/15/2014 12:16 AM »
I don't know
and
I don't know

Thank you

and

Thank you

Now. Will you answer why higher power devices have not been tested?
My opinion: They have and it works, therefore Top Secret.
What can you say?

Offline Rodal

  • Senior Member
  • *****
  • Posts: 5895
  • USA
  • Liked: 6045
  • Likes Given: 5325
Re: EM Drive Developments
« Reply #566 on: 09/15/2014 12:20 AM »
I don't know
and
I don't know

Thank you

and

Thank you

Now. Will you answer why higher power devices have not been tested?
My opinion: They have and it works, therefore Top Secret.
What can you say?

I don't know  :)

and

I have no idea

and

If I would know that the answer is top secret, I certainly would not be able to answer it anyway   :)
« Last Edit: 09/15/2014 12:21 AM by Rodal »

Offline IslandPlaya

  • Full Member
  • ****
  • Posts: 582
  • Outer Hebrides
  • Liked: 163
  • Likes Given: 166
Re: EM Drive Developments
« Reply #567 on: 09/15/2014 12:24 AM »


I have a readily detectable mass effect on my bookshelf at least.

Thread winner! Nice quip John.

As for the "why no cubesat test," so far I don't believe any of the testing of Eagleworks has been of steady-state devices, and when you factor in how much the power circuits would add to the mass, at current force levels you would need a lot of sustained thrust time to see an orbital mechanics effect from ground-based observation.

Thanks for answering this. So it's going to need a lot more development to get to this stage then.
Now. Will you answer why higher power devices have not been tested?
My opinion: They have and it works, therefore Top Secret.
What can you say?

Offline birchoff

  • Full Member
  • **
  • Posts: 273
  • United States
  • Liked: 125
  • Likes Given: 95
Re: EM Drive Developments
« Reply #568 on: 09/15/2014 12:26 AM »
To put this comparison more bluntly:

Ratio of measurements for Shawyer/SPR Ltd.'s device compared to Cannae's device:

THRUST FORCE: 400 to 4250 times higher for Shawyer/SPR Ltd.'s device than for Cannae's device
SPECIFIC FORCE  ( Thrust Force / Input Electric Power) : 14 to 286 times higher for Shawyer/SPR Ltd.'s device than for Cannae's device

_____________________________________________________________________________

Ratio of measurements for Boeing/DARPA's device compared to Cannae's device:

THRUST FORCE: 0.5 to 2.75 times higher for Boeing/DARPA's device than for Cannae's device
SPECIFIC FORCE  ( Thrust Force / Input Electric Power): 714 to 14300 times higher for Boeing/DARPA's device than for Cannae's device

_____________________________________________________________________________

Since what we are looking for is the highest Thrust Force and the highest Specific Force possible, why is the latest discussion in this forum concentrating on the performance of the latest round of tested devices, when they appear to have among the lowest measured thrust forces and the lowest specific force ?

I think the answer to this question is simply because EagleWorks only presented a paper that outlined tests on the Cannae and Tapered Frustum. I am equally puzzled as you, since the Boeing device seems to be much more interesting. But outside of the deck and the 2013 update you linked to there is ZERO information about the Boeing test article which I find very curious given the results. From the 2013 update you linked to before, it looks like the Boeing device was tested along side the Cannae and Tapered Frustum. So unless there is some sort of NDA in place or some sort of time constraint on compiling the information necessary for inclusion in the paper or some combination there of. I cannot see a reason for why it wouldn't be included.

On a separate note, from the limited information available I am beginning to wonder if the Boeing device wasn't a Mach Effect/Woodward Effect device.

Offline Rodal

  • Senior Member
  • *****
  • Posts: 5895
  • USA
  • Liked: 6045
  • Likes Given: 5325
Re: EM Drive Developments
« Reply #569 on: 09/15/2014 12:35 AM »
To put this comparison more bluntly:

Ratio of measurements for Shawyer/SPR Ltd.'s device compared to Cannae's device:

THRUST FORCE: 400 to 4250 times higher for Shawyer/SPR Ltd.'s device than for Cannae's device
SPECIFIC FORCE  ( Thrust Force / Input Electric Power) : 14 to 286 times higher for Shawyer/SPR Ltd.'s device than for Cannae's device

_____________________________________________________________________________

Ratio of measurements for Boeing/DARPA's device compared to Cannae's device:

THRUST FORCE: 0.5 to 2.75 times higher for Boeing/DARPA's device than for Cannae's device
SPECIFIC FORCE  ( Thrust Force / Input Electric Power): 714 to 14300 times higher for Boeing/DARPA's device than for Cannae's device

_____________________________________________________________________________

Since what we are looking for is the highest Thrust Force and the highest Specific Force possible, why is the latest discussion in this forum concentrating on the performance of the latest round of tested devices, when they appear to have among the lowest measured thrust forces and the lowest specific force ?

I think the answer to this question is simply because EagleWorks only presented a paper that outlined tests on the Cannae and Tapered Frustum. I am equally puzzled as you, since the Boeing device seems to be much more interesting. But outside of the deck and the 2013 update you linked to there is ZERO information about the Boeing test article which I find very curious given the results. From the 2013 update you linked to before, it looks like the Boeing device was tested along side the Cannae and Tapered Frustum. So unless there is some sort of NDA in place or some sort of time constraint on compiling the information necessary for inclusion in the paper or some combination there of. I cannot see a reason for why it wouldn't be included.

On a separate note, from the limited information available I am beginning to wonder if the Boeing device wasn't a Mach Effect/Woodward Effect device.

Please also consider that:

A) The Boeing/DARPA measurements show a sudden impulse of very short duration instead of the practically rectangular pulses measured with the latest tested devices (Cannae and (Fustrum) Tapered Cavity).   That may be a problem concerning the Boeing/DARPA device as what is needed is steady state thrust.

and

B) NO Information gets out on top secret work.  None.  Nada.  At the time of the Manhattan Project you didn't have snapshots with small amounts of information.  You had nothing getting out.  The NASA Eagleworks 2013 update on the Boeing/DARPA device (look at the link) seems to be on a Yahoo server with the address xa.yimg.com. All of these are servers that host the graphic images of Yahoo pages (y=Yahoo + img=image).
« Last Edit: 09/15/2014 12:50 AM by Rodal »

Offline birchoff

  • Full Member
  • **
  • Posts: 273
  • United States
  • Liked: 125
  • Likes Given: 95
Re: EM Drive Developments
« Reply #570 on: 09/15/2014 12:37 AM »

I have a readily detectable mass effect on my bookshelf at least.

Thread winner! Nice quip John.

As for the "why no cubesat test," so far I don't believe any of the testing of Eagleworks has been of steady-state devices, and when you factor in how much the power circuits would add to the mass, at current force levels you would need a lot of sustained thrust time to see an orbital mechanics effect from ground-based observation.

Yet, that is exactly what is necessary.  The terrestrial based apparatus seems subject to many more constraints than a free body experiment would be subject to. Don't tell the proponents that I'm suggesting an appropriate scaling up of their apparatus.  They have neither a sense of humor nor perspective.

As a proponent for continued experimentation into these types of devices, I can say that I would love to see them scaled up and tested in a cubesat. However, I am also aware that nothing is that easy. These devices have not been proven to be real effects yet. which means we have no clue what the operating parameters are. Now as long as there are experiments we can do on terra firma that are cheaper. My vote is to complete those experiments first. Once that is done we can begin planning the cubesat version.

Offline aceshigh

  • Full Member
  • ****
  • Posts: 608
  • Liked: 171
  • Likes Given: 16
Re: EM Drive Developments
« Reply #571 on: 09/15/2014 12:51 AM »
Why is that every time something like this appears that there is certain strand of belief online that they must have had these for years but kept them secret. It's a depressingly recurrent theme for cutting edge technology whatever the field and I don't know what it is says about scientific literacy in the public at large.

I'm not asking why or claiming that he's keeping it secret. I'm asking why a larger one, which would (I hope) help demonstrate that EM drive technology is a real thing, hasn't been built yet.


not sure, but considering Star Drive is a electric-engineer, I am certain he has a good explanation for why not.

for Mach Effect devices, I know they need piezo-electric materials and ceramics that are just too expensive for anyone without some good financial backup.

Offline birchoff

  • Full Member
  • **
  • Posts: 273
  • United States
  • Liked: 125
  • Likes Given: 95
Re: EM Drive Developments
« Reply #572 on: 09/15/2014 12:54 AM »
To put this comparison more bluntly:

Ratio of measurements for Shawyer/SPR Ltd.'s device compared to Cannae's device:

THRUST FORCE: 400 to 4250 times higher for Shawyer/SPR Ltd.'s device than for Cannae's device
SPECIFIC FORCE  ( Thrust Force / Input Electric Power) : 14 to 286 times higher for Shawyer/SPR Ltd.'s device than for Cannae's device

_____________________________________________________________________________

Ratio of measurements for Boeing/DARPA's device compared to Cannae's device:

THRUST FORCE: 0.5 to 2.75 times higher for Boeing/DARPA's device than for Cannae's device
SPECIFIC FORCE  ( Thrust Force / Input Electric Power): 714 to 14300 times higher for Boeing/DARPA's device than for Cannae's device

_____________________________________________________________________________

Since what we are looking for is the highest Thrust Force and the highest Specific Force possible, why is the latest discussion in this forum concentrating on the performance of the latest round of tested devices, when they appear to have among the lowest measured thrust forces and the lowest specific force ?

I think the answer to this question is simply because EagleWorks only presented a paper that outlined tests on the Cannae and Tapered Frustum. I am equally puzzled as you, since the Boeing device seems to be much more interesting. But outside of the deck and the 2013 update you linked to there is ZERO information about the Boeing test article which I find very curious given the results. From the 2013 update you linked to before, it looks like the Boeing device was tested along side the Cannae and Tapered Frustum. So unless there is some sort of NDA in place or some sort of time constraint on compiling the information necessary for inclusion in the paper or some combination there of. I cannot see a reason for why it wouldn't be included.

On a separate note, from the limited information available I am beginning to wonder if the Boeing device wasn't a Mach Effect/Woodward Effect device.

Please also consider that:

A) The Boeing/DARPA measurements show a sudden impulse of very short duration instead of the practically rectangular pulses measured with the latest tested devices (Cannae and (Fustrum) Tapered Cavity).   That may be a problem concerning the Boeing/DARPA device as what is needed is steady state thrust.

and

B) NO Information gets out on top secret work.  None.  Nada.  At the time of the Manhattan Project you didn't have snapshots with small amounts of information.  You had nothing getting out.  The NASA Eagleworks 2013 update on the Boeing/DARPA device (look at the link) seems to be on a Yahoo server with the address xa.yimg.com. All of these are servers that host the graphic images of Yahoo pages (y=Yahoo + img=image).

Agreed on the top secret comment. But a NDA is a little bit more forgiving than declaring something Top Secret. For example EagleWorks could have been allowed to only report on the results. Which is what they did. Compared to the Cannae and Tapered device where they were able to report on their construction and the testing protocol.

Offline frobnicat

  • Full Member
  • ****
  • Posts: 518
  • Liked: 500
  • Likes Given: 151
Re: EM Drive Developments
« Reply #573 on: 09/15/2014 12:59 AM »

an interesting paper by Dr. White.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf

In particular, I find the Math toward the end of the slide show  interesting.

Thanks @aero for bringing this up. I wish we would address slides 56 to 60 of this paper   :)

**** and I don't mean this as a criticism, the equations of Dr. White are scattered in several Power Point slide presentations, I have NOT been able to find them all contained in a single entire paper
I mean this constructively, the more we address Dr. White's equations, the more fair our assessment and also the better we will understand whether his explanations are plausible or not

desperate attempt, please don't read and ignore unless you are yourself desperate :

I understand the interest of addressing those equations but at this level I just can do dimensional analysis (first glance seems ok, but then one wouldn't expect otherwise). Quantitatively from the equations couldn't tell deep insights from mere numerology. A few slides but no paper to the scientifically literate (but not specialist or follower) don't help. Hope someone can clarify because what I'm understanding qualitatively (not much either) is that mass alters "local vacuum density" and that makes either for more "vacuum plasma" to push on, or is it a difference in potentials to exploit ? See how clueless, can't even tell if equation 1 slide 56 is the starting hypothesis and then deriving form there, or if the rest is supposed to illuminate this hypothesis, or if we have some circular reasoning (well, there is some circularity in any successful theory, this can be just "self consistency", not a counter argument by itself), or if this is just a way of expressing in a different way of what we already know in mainstream physics like, you know, for instance naked particle vs dressed particle (and what is expressed as "affected vacuum fluctuation density" would be the "density of the dress") (not likely as this is specific to fields others than gravity while formula 1 is only about energy densities, isn't it ?)

So, na´vely I would say : if something more is linked to local mass_energy density (is that it rho m_local ?) how can you exploit it energetically as it is still a local minimum energy state in its own specificity. Not clear, a classical analogy would be : a liquid (surface of minimum energy) forms a meniscus close to the wall of a container, at this point the surface is higher (take a concave meniscus) than the rest of the surface. That don't make it possible to exploit this difference of height to generate energy as the surface is of minimal energy, given the wall of the container is there : it both makes possible the change of altitude of surface, and prevents that to be used for useful work. If one could instantly make the wall vanish, then this meniscus is no longer a minimum energy surface and work can be recovered, but not more than what it took to "make it vanish". Meaningless talk probably.

Equation 2 : ok so this is principle of equivalence, I guess we could expect the same magnitude as Hawking radiation (no ?), so a bit surprised that a mundane mass density like a dielectric (not even a neutron star) could make much difference with nothing. Let's proceed.

Next (still on slide 56)
Quote
The tools of MagnetoHydroDynamics (MHD) can be used to model this modified vacuum fluctuation density analogous to how conventional forms of electric propulsion model propellant behavior.
don't understand (trying) is that : MHD tools used to model the coupling of RF field with this denser vacuum ... ?

There I'm stuck for now.

If the other equations/slides bring something else as to why some better than 1/c thrust/power ratio can be obtained at all (however small, regardless of the fact that vacuum would be denser than usual in a capacitor) it didn't struck me.

Also, on a side note, the proposed mission profiles are calculated with good old Newtonian mechanics, from a given thrust/power ratio. So while it is interesting to discuss the equations deriving such ratio (or the simple possibility of such ratio > 1/c) from possible hypothesis, that shouldn't prevent anyone to draw conclusions of the ratio without resorting to such hypothesis/equations or making calculation in such formalism.


            exotic physics                    Newtonian
Hypothesis ---------------> thrust/power -----------------> result (real cheap energy)



Offline Rodal

  • Senior Member
  • *****
  • Posts: 5895
  • USA
  • Liked: 6045
  • Likes Given: 5325
Re: EM Drive Developments
« Reply #574 on: 09/15/2014 12:59 AM »
Why is that every time something like this appears that there is certain strand of belief online that they must have had these for years but kept them secret. It's a depressingly recurrent theme for cutting edge technology whatever the field and I don't know what it is says about scientific literacy in the public at large.

I'm not asking why or claiming that he's keeping it secret. I'm asking why a larger one, which would (I hope) help demonstrate that EM drive technology is a real thing, hasn't been built yet.


not sure, but considering Star Drive is a electric-engineer, I am certain he has a good explanation for why not.

for Mach Effect devices, I know they need piezo-electric materials and ceramics that are just too expensive for anyone without some good financial backup.

The Cannae thruster (which has among the lowest thrust force and the lowest specific force measured at NASA Eagleworks) has an (inexpensive) Teflon dielectric resonator.   The Paul March Woodward-Effect devices measurements at NASA Eagleworks showed significantly higher thrust and specific force than the Cannae device...
« Last Edit: 09/15/2014 01:50 AM by Rodal »

Offline Rodal

  • Senior Member
  • *****
  • Posts: 5895
  • USA
  • Liked: 6045
  • Likes Given: 5325
Re: EM Drive Developments
« Reply #575 on: 09/15/2014 01:37 AM »

an interesting paper by Dr. White.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf

In particular, I find the Math toward the end of the slide show  interesting.

Thanks @aero for bringing this up. I wish we would address slides 56 to 60 of this paper   :)

**** and I don't mean this as a criticism, the equations of Dr. White are scattered in several Power Point slide presentations, I have NOT been able to find them all contained in a single entire paper
I mean this constructively, the more we address Dr. White's equations, the more fair our assessment and also the better we will understand whether his explanations are plausible or not

...attempt,.....

Thanks for taking a stab at  it.  Now you have a better idea of what his model is. I'm trying to find the link for a presentation where Dr. White derived his calculation of what he calls the "local vacuum density" as the geometric mean of the local material density (which he calculates from the radius of the hydrogen atom nucleus and the mass of a proton to obtain the density of the hydrogen nucleus) and the quantum vacuum density.  I can no longer find that link using Google   :(.  I recall that Dr. White's calculation was based on a Mean Free Path argument...  In any case, you can see that Dr. White didn't just come up with a "local vacuum density" number to arbitrarily fit experimental results, but that he has at least a "back of the envelope" argument for it...  This "local vacuum density" is of course several orders of magnitude larger than the zero point energy.
« Last Edit: 09/15/2014 02:28 AM by Rodal »

Offline Rodal

  • Senior Member
  • *****
  • Posts: 5895
  • USA
  • Liked: 6045
  • Likes Given: 5325
Re: EM Drive Developments
« Reply #576 on: 09/15/2014 02:56 AM »

an interesting paper by Dr. White.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf

In particular, I find the Math toward the end of the slide show  interesting.

Thanks @aero for bringing this up. I wish we would address slides 56 to 60 of this paper   :)

...

... at this level I just can do dimensional analysis ....

Most problems in Engineering were solved with non-dimensional analysis (think of heat transfer,  Aeronautical Engineering, etc.) and a slide-rule at a time that numerical computations were not available.  Nothing wrong with that  ;) .  And it is always good to have a very simplified physical model that abstracts the main features.

What is out of the ordinary here is that exotic physics (electron/positron pairs of virtual particles modeled as a  MagnetoHydrodynamics plasma) is involved here, but let's see where this leads...
« Last Edit: 09/15/2014 02:59 AM by Rodal »

Online Stormbringer

  • Full Member
  • ****
  • Posts: 1308
  • Liked: 231
  • Likes Given: 86
Re: EM Drive Developments
« Reply #577 on: 09/15/2014 03:03 AM »


B) NO Information gets out on top secret work.  None.  Nada.  At the time of the Manhattan Project you didn't have snapshots with small amounts of information.  You had nothing getting out.  The NASA Eagleworks 2013 update on the Boeing/DARPA device (look at the link) seems to be on a Yahoo server with the address xa.yimg.com. All of these are servers that host the graphic images of Yahoo pages (y=Yahoo + img=image).

hmmmm. In Dr whites earlier video i recall Dr white stating that his Q thruster experiments were farther along than his warp interferometry experiment but he could not discuss the former in detail because... he either said it was classified or else subject to secrecy due to NDA or something like that.

as to the Manhattan project several of the scientists on the team were giving data to the soviets for ideological reasons even before the project was finished. They feared America would become an unstoppable evil empire if they were the lone nuclear power.
« Last Edit: 09/15/2014 03:04 AM by Stormbringer »
When antigravity is outlawed only outlaws will have antigravity.

Offline birchoff

  • Full Member
  • **
  • Posts: 273
  • United States
  • Liked: 125
  • Likes Given: 95
Re: EM Drive Developments
« Reply #578 on: 09/15/2014 04:07 AM »
@Rodal

I think the answer to your thrust descripancy between the Cannae and the Tapered Frustum  devices may be partly answered by the size of the dielectric. According to the pictures and comsol models in the paper the size of the dielectric in the Cannae device has to be much smaller than the die electric in the Tapered Frustum. My guess as to why Cannae has a smaller dielectric would be that the theory they presented at the conference considers the slots in the cavity to be the source of the thrust (you can either buy the paper from AIAA to get access to their theory, or leverage the way back machine here => http://web.archive.org/web/20140517034519/http://cannae.com/, along with the patent descriptions here => https://www.google.com/?tbm=pts&gws_rd=ssl#tbm=pts&q=inassignee:%22Cannae+Llc%22). Interestingly, since the NASA testing it looks like the inventor at Cannae has moved away from that theory of operation and is building new devices that in the companies words...

Quote
Inventor Guido Fetta has developed a 2nd technology that develops thrust without the use of on-board reaction mass.  This new technology uses RF interactions with a dielectrically loaded waveguide to produce thrust.  This new technology functions by a mechanism that is different from the Cannae Drive thrust mechanism.  Cannae LLC has patent pending status on a wide range of designs based on this new technology.
<<http://www.cannae.com/updates

As for your question about the thrust and specific force numbers reported in the Deck for Shawyer's EmDrive. It is my understanding from second and third hand information that while Dr. White originally attempted to replicate Shawyer's device, they failed to get positive results. I believe this is what was being referenced in the paper

Quote
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.
<< Pg 18, Anomalous Thrust Production From RF Test Device.

So if the information is accurate then its most likely that the numbers on slide 40 of that deck are coming from one of Shawyer's papers or the Chinese papers (I have yet to double check that).

Offline frobnicat

  • Full Member
  • ****
  • Posts: 518
  • Liked: 500
  • Likes Given: 151
Re: EM Drive Developments
« Reply #579 on: 09/15/2014 10:18 AM »
In that vein, I think it would be best to discuss the experiments without addressing any controversial physical explanation for the time being."

Maybe we could split another thread for "Theoretical aspects of space drives" ?

Sill thinking that, between theoretical speculations of stratophysics of the unknown, and down to earth practical experimental apparatus and results inquiries, it is important to address uncontroversial physics consequences of said results, regardless of specific theories. Even if the various propellentless thrusts results weren't guided by any kind of backing theory and had been stumbled on by chance, that wouldn't prevent us to use the effect to the fullest extent permitted by Newtonian laws.

Sorry I will shuffle a little bit the quotation order and select fragments for my dissertation
Quote
PS:  A Hall thruster's input power to thrust efficiency or specific thrust is around 0.05 N/kWe using today's commercially available thrusters.  Air breathing jet engines can have thrust efficiencies of up to ~75 N/kWe at take off, so assuming a 0.40N/kWe for our Copernicus Orbital calculations is not way out on a limb, and in fact is representative of the performance of my first two Mach-Lorentz Thrusters (MLT) that I built in 2003 and 2004 and reported on in my STAIF-2006 paper.

So those mission profiles are sold with the following hypothesis that :

- a thrust/power>>1/c effect is possible,it is independent of speed, without expelling mass (that is without spending more onboard mass than the equivalent mass_energy to power the system, negligible so far)

- approaching 1N/kW is possible/expected/has been measured already

- in this hypothesis "thrust" and "power" retain the meaning they usually have, the observed acceleration of a free floating spacecraft will be thrust/mass, the total energy used by the onboard generator will be the power integrated on time. Mission profiles are calculated with Newtonian dynamics. While backing theories can explain why previous hypothesis hold, one don't need to use those special formalisms to set up mission profiles, just plug in the thrust/power number into classical framework (that is Newtonian when speed<<c and total energy/c▓ << spacecraft's mass)

Am I wrong on any of that ? Are there any (acquired) speed corrections to the thrust/ratio used in the proposed mission profiles ?

Quote
BTW, I'm a little late is saying this, but tell Goat Guy that he needs to perform his energy conservation analysis in the 4D GRT formalism and not the flat space-time Newtonian version he's been using to date when performing M-E or Q-Thruster based momentum and energy conservation calculations.  Woodward's 2004 M-E derivation paper's appendix A can show what's needed here.

I'm not Goat Guy but what he said about the tremendous practical energy in/practical energy out leverage of the mission profiles seems sensible to me : the net useful result is "very cheap classical energy". If a theory can explain where this energy comes from and keep energy balance overall, great, but that is irrelevant as far as mission profiles are concerned. In what would the 4D GRT be necessary to derive the practical consequences of the effect, would it make any difference for mission profiles ?

Cheap classical useful energy is not shocking by itself, arguably a solar sail has an infinite thrust/power ratio from the standpoint of a spacecraft : net thrust with 0 power. And therefore we could devise some solar windmill that are "free" energy generators. Probably not practical.

Thing is : with the claimed(used in mission profiles) thrust/power ratios approaching 1N/kW we can devise very near practical energy generators, suffice to rotate the thruster at the rim of a rotor with a tangential speed a bit more than 1/ratio = 1km/s. Since there is no complex or moving parts in those thrusters it should be relatively straightforward, the RF generator could be mounted fixed, and give the power through a waveguide coaxial with the shaft. This is only a technological problem of high specific strength materials and maybe some (not enormous) tapering of supporting rotating arm section if a bit more 2km/s needed. If 0.5 chained efficiency of the electric dynamo on the shaft and the RF generator then 5km/s needed with 0.4N/kW to reach breakeven, hard but not impossible.

So the question is, and remains, why the results are not also sold on that possibility, should they hold and be classically interpreted for propulsion purpose, why would it be impossible/taboo to classically derive this incredibly useful consequence of "very cheap energy" generators?

The power/mass ratios might be near 10 W/kg (optimistically say with 1N/kW thruster, 100kg system, generating 1N at 3km/s, 3kW mechanical, 2.7 electric at dynamo, 2kW  used for 50% efficiency 1kW output RF generator, 700W net power breakeven, 7W/kg)
7W/kg is not much specific power but hey, it's free ! A spacecraft 200kg with a 100kg generator like that, and a thruster at 1N/kW would have acceleration of .7/200 = 3.5e-3 m/s▓, forever, for free.
That is about 100km/s a year, a bit short for interstellar but making roaming the suburbs a breeze.

Has this real possible and desirable consequence of the effect, good energy generators for space (and earth), been mentioned by the proponents of the effect, and if not why not ?

Quote
As for White's Q-Thrusters, energy & momentum conservation is observed by the fact that the vacuum derived propellant has an energy equivalent mass that does have a velocity less than c.  And just like the standard rocket equation, your rocket's maximum obtainable velocity is dependent on the maximum exhaust velocity of the Q-Thruster that is driven by all its local and perhaps gravitational field input energies.  Our current model for same indicates that these vacuum e/p pair like propellant velocities should be in the range of 10,000-to-10,000,000 m/s for the geometries and input power levels we've looked at to date, but of course only if our Q-Thruster model Excel sheet is correct. 

If I understand well, the energy you have to put in the thruster to get the thrust has a mass equivalent, and like for a photon rocket after some point of very very intense onboard power generation the mass of the spacecraft is depleting and therefore we have a rocket equation hence a "maximum" practical attainable speed. Is that it ?

Anyway, either the mission profiles at 0.4 N/kW and absolute (?) speeds < 100km/s are possible, and so is a near practical "cheap energy generator", or the generator is not possible because 0.4N/kW starts to decrease above ~2.5 km/s but then interesting mission profiles are no longer possible either.

Best

Tags: