Author Topic: EM Drive Developments Thread 1  (Read 762791 times)

Offline Rodal

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Re: EM Drive Developments
« Reply #2720 on: 10/28/2014 10:13 AM »
Regarding the radius of curvature .1 cm or whatever. Isn't that outside the cavity? Or is the drawing printed up side down? Not likely without deliberate deceit.

As to the base drawing attached here, what is that detailed? Is it a 3 cm by 1 cm deep torus around the outer rim of the base? If the device is designed to bounce microwaves around the corner then what would the effective depth be? Before answering, please evaluate whether or not microwaves could behave in that fashion.

If so, then Cannae's idea would be for all the end reflections to occur in the same axial direction.

To understand the construction, one needs to looks at the picture reproduced below (all the drawings and this picture are in http://web.archive.org/web/20121104025749/http://www.cannae.com/proof-of-concept/design   )

The top plate is indeed printed upside down with respect to the bottom plate.

The radius R.1000 is inside the resonating cavity.

Furthermore, there is another 1.000 cm of resonating cavity from the bottom cavity.

So, if the R.1000 was meant to read 1.000 cm the total resonating cavity height is:
1.000 (dimensioned on bottom plate)
+0.4 approximately (straight vertical not dimensioned on bottom plate)
+1.000 (from R.1000 incorrectly dimensioned on top plate, should be 1.000)
+0.6 approximately ((straight vertical not dimensioned on top plate)
___________
~ 3.0 cm total cavity height



Take a gander at the picture below



The dimensions are in cm.  It says so in the drawing:

Quote
Figures 1 and 2 depict two halves of the QDrive cavity. The dimensions are in cms.

The 3 cm by 1 cm deep torus around the outer rim of the base is outside, below the main cavity.

This torus is not receiving microwaves (the main cavity is the one receiving the microwaves).  Take a look at the picture: there is metal separating the resonating cavity from the torus (the torus is not seen in the picture, it is located below what's shown). 


« Last Edit: 10/28/2014 11:44 AM by Rodal »

Offline Rodal

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Re: EM Drive Developments
« Reply #2721 on: 10/28/2014 10:35 AM »
But how we could know that for sure if not trying ? And even if nothing conclusive can be inferred, we can still further the subject about what is outright impossible and what is still on the table. Also surveys of many (ok, not that many in present situation) unreliable sources can turn up aspects unseen by each individual publication. This is not automatic, there is no assurance that all this time and energy won't be a waste, this is the rule of the game of being impatient (and I see lot of impatient people here) that is somehow also the rule that applies when undertaking anything at the edge and high risk/high payoff. Though in this case I wonder who would pay us... so we are only left with the high risk  :)
I completely agree: I see lots of impatience as well.  I also see sermonizing about "you are going to find nothing here."

It reminds me of when I'm doing a failure analysis and impatient people want answers immediately.  Hence people quickly jump to two extremes: either that one should know the cause of failure just by looking at something (rather than analyzing the data) which is seldom the case or they are too impatient to wait the results of analysis and they jump the gun by thinking that one is never going to find the cause of failure.
« Last Edit: 10/28/2014 10:57 AM by Rodal »

Offline Rodal

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Re: EM Drive Developments
« Reply #2722 on: 10/28/2014 11:50 AM »
Also what is being missed is that all the experimenters have huge problems conducting the experiments.  The problem is not making the cavity.  The difficulty is that the response is a resonant response over an extremely small bandwidth.  The amplitude vs. frequency response is very nonlinear.

The researchers don't quite know at what precise frequency the maximum amplitude takes place and they lack the precise equipment to keep the frequency steady at the peak amplitude.

It is no surprise that there are huge uncertainty bars because the theoretical explanations are predicated on knowing precisely the Q and the frequency of resonance which are not kept steady during the experiment.
« Last Edit: 10/28/2014 11:51 AM by Rodal »

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #2723 on: 10/28/2014 11:53 AM »
This device is fictional.   No one would build a dewar this way.

Couple of random links for dewars. Buy it now at:

http://www.cryofab.com/products/cmsh_series


All of those references except the last one refer to cryogen storage dewars.

I'm not trying to build one. I'm doing a bit o' research to understand more of what goes into one.  Your comment was a reference to an unqualified "dewar".  Just sayin'.

Obviously, a thermos bottle is less complicated than a refrigerator, and that is the analogy.  In ten minutes of poking around on the intertubes, a "reasonably educated" person can verify for himself that the illustrated dewar is a pretense.

Further analysis of the anomalous thrusts based on that picture is a waste of time.
Sometimes I just flat out don't get it.

Online Mulletron

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Re: EM Drive Developments
« Reply #2724 on: 10/28/2014 12:13 PM »
That's a little off.  I suggest try to read the English bits on the wiki page linked above.  The essential difference is that Woodward never even makes reference to virtual particles.  His theory does not require them at all.  In fact, in his book he explains that we don't really need them for anything.  Contrary to popular notions floating around in the advanced propulsion ZPF and QVF camps (and now this new one) virtual particles are not required to explain things like Casimir Effect.  There are perfectly reasonable explanations for CA that do not require virtual particles, but you would never get that listening to anyone who believes this wonky physics.  And I would just note to you, the percent of people who believe in treating virtual particles this way is vanishingly small.  That's why Sean Carroll at Cal Tech called this stuff "BuII$hit".

Well those high vis physicists were calling this stuff bs because they disagree with the notion of the QV acting as a plasma. The notion of virtual particles existing is generally accepted as true. Yes they are also used as an accounting mechanism in Feynman diagrams for example. A friendly reminder, the quantum world is driven by probability (things happen on a spectrum somewhere between very low and very high probabilities), and these virtual particles have a very low probability of existing at any given instant. There is no logical way to draw an arbitrary line and say something has exactly zero probability of existing.
Challenge your preconceptions, or they will challenge you. - Velik

Offline Rodal

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Re: EM Drive Developments
« Reply #2725 on: 10/28/2014 12:18 PM »
A common tautology found in any investigation:

"Further analysis of ...(by anybody that thinks the investigation is a waste of time) ...is a waste of time"

This tautology is very commonly found in failure analysis, for example.  The impatient ones start with the premise: you are never going to find the cause of failure.

It is also found in life: don't take chances, don't start your own business, you are going to fail, it is a waste of time...  Don't invest $$$ in the market, you are going to lose. 

Don't ask the girl to dance, she'll turn you down.  Don't ask her out, she'll turn you down  :)

I understand that people may be interested in different things, and some may not want to invest any time or take chances on something.  But why sermonize to others on what is worthwhile to spend time on or take chances on?

« Last Edit: 10/28/2014 12:37 PM by Rodal »

Offline Ron Stahl

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Re: EM Drive Developments
« Reply #2726 on: 10/28/2014 12:32 PM »
Thing is, there is many many places where people are saying "all those people working on propellantless propulsion are quacks.
That's exactly right.  When examining the issue of propellantless thrust, one is forced to look at things like personalities because people are the ones building and reporting on this stuff.  You want to measure warrant for belief in any particular scheme, and engineers want to focus on the technical aspects even when they don't understand the underlying theory, but the job is much bigger than this.  If you don't avail yourself to examining simple character quality, you're then left having to do the same analysis for Searl as you do for Eagle, and that is just a lot of wasted effort.  So even though I agree we should be focused on technical aspects in this forum, it's also true these other things are extremely important and you can't just overlook them.


You guys type too late for us East coasters to keep up.  Someone asked about how to test this stuff at ISS.  In order to do a TRL7 demonstration, you have to test in space.  In order to do this as efficiently as possible, IMHO one wants to miniaturize the power system so the whole thing will fit into a nanosat.  NASA lofts nanosats to ISS for free right now, and launches them out the little spring-loaded gizmo.  If you build a propellantless nano be it 1U, 2U or 3U, you can get the launch to space for free which recovers your miniaturization investment and removes the greatest cost barrier form such a project.  You can fly the thing around inside ISS until you want a more dramatic presentation and you can then fly it around outside as well.  Where you can go outside should be limited only by your ability to monitor the spacecraft, so if you have a few watts of transmitter, you can actually maneuver to another orbit like equatorial (something that's never been done from ISS) and who knows where you go from there?  The little GN&C's and startrackers available in modern cubesat kits may even be able to manage cislunar or interplanetary flight (and NASA has had their eye on interplanetary cubesats for quite some time now).  So the scope of any demonstration is not as easy to describe as one might guess.  One thing is certain--you want to plan a demonstration where the craft thrusts as often as possible for as long as possible so you can get duration data.  So really were one able to set up a round trip transit between say, Earth and Mars, that would be a worthy goal.  Mars Recon Orbiter has the new Elektra radio aboard and one could plan to use it periodically.

One can purchase a fully assembled nanosat built from parts previously tested in space for about $30k, so using a nano saves on the cost of the craft as well as the launch.  In most projects like this, it is the finances that stop the project, so planning to test as cheaply as possible makes good sense from a project manager's perspective and cubesats are about the cheapest space propulsion demo platform possible.
« Last Edit: 10/28/2014 12:41 PM by Ron Stahl »

Online Mulletron

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Re: EM Drive Developments
« Reply #2727 on: 10/28/2014 12:53 PM »
Yes well, I understand your point but it remains that your practical application is incorrect.  It does not matter which explanation is closest to the observed value, especially when the calculations come after the data is received.  This is simple scientific method any engineer should be aware of.  How close a wrong answer is to the observed value forms no correlation whatsoever with any probability of its veracity, and asking people to think this way is inviting them to form a thinking error.  I'm perhaps overly sensitive to this error because Dr. White has on many occasions compare his model to others in this way, inviting people to form this invalid conclusion.  And it is easy to see how this happens.  Fallacies are tricky things.

Yes I agree with you. Some of the more recent mathematical predictions from http://physicsfromtheedge.blogspot.it/ and supporters are based on foundations which are teaching light new tricks ("light does have an inertial mass"), and other hasty leaps (not taking into action principles, magnitudes of competing interactions), ignoring the second law of motion.....The list is long, read for yourself. A few weeks ago, I swear I saw light suddenly go to 1.2 billion meters per second to justify a calculation. (It is in this forum I promise) The predictions may be close to being right, but are exactly wrong. A wise poster here named John should tell us about his "exactly wrong" analogy.

Oh yeah, I created a new universe inside a copper can too.  ;)

Edit:

So yeah, a lot of liberties have been taken to make the data fit the situation. I think I can safely say that no one here was born with all the answers to the problem of anomalous thrust from EMdrive, thus it is a learning experience for all those who wish to explore the problem and propose answers.

« Last Edit: 10/28/2014 02:31 PM by Mulletron »
Challenge your preconceptions, or they will challenge you. - Velik

Offline Rodal

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Re: EM Drive Developments
« Reply #2728 on: 10/28/2014 12:54 PM »
Table comparing Shawyer and McCulloch's predictions with measurements

c= 299705000 m/s (speed of light in air)
c= 299792458 m/s (speed of light in vacuum) (for Cannae Superconducting)

lengths in meter
rfFrequency in 1/second (microwave frequency during test)
power in watts
force in milliNewtons
force per PowerInput in milliNewtons/kW

Note: SmallDiameter for Shawyer's EM Drives obtained from his reported ShawyerDesignFactor .

predicted force (either Shawyer or McCulloch) followed (in parenthesis) by ratio of prediction divided by measurement

ShawyerForce = (2 * PowerInput * Q / c ) * ShawyerDesignFactor

McCullochForce1 = ( PowerInput * Q / rfFrequency ) * ((1/smallDiameter) - (1/bigDiameter))

McCullochForce2 = ( PowerInput * Q / c ) * ((cavityLength/smallDiameter) - (cavityLength/bigDiameter))


ShawyerForcePerPowerInput = (2 * Q / c ) * ShawyerDesignFactor
McCullochForce1PerPowerInput = (Q / rfFrequency ) * ((1/smallDiameter) - (1/bigDiameter))
McCullochForce2PerPowerInput = (Q / c ) * ((cavityLength/smallDiameter) - (cavityLength/bigDiameter))


Force/PowerInput of a Photon Rocket = 1 / c

Force/PowerInput ratios divided by the Force/PowerInput of a Photon Rocket, divided by Q are:

Shawyer/PhtnRckt/Q = 2 * ShawyerDesignFactor
McCulloch1/PhtnRckt/Q = (c / rfFrequency ) * ((1/smallDiameter) - (1/bigDiameter))
McCulloch2/PhtnRckt/Q = ((cavityLength/smallDiameter) - (cavityLength/bigDiameter))





(* Cannae Superconducting *)
rfFrequency = 1.047*10^9;
cavityLength = 0.01+0.004+0.006+0.01 = 0.03;
bigDiameter =(22.86-2*(0.00430)) = 0.220;
smallDiameter = bigDiameter-2*0.01=0.200;
ShawyerDesignFactor = 0.028963

power =  10.5
Q = 1.1*(10^7)

measured force = 8 to 10
ShawyerForce = 22.32
McCullochForce1 = 50.14
McCullochForce2 = 5.254

measured ForcePerPowerInput = 761.9 to 952.4
ShawyerForcePerPowerInput = 2125.
McCullochForce1PerPowerInput = 4776.
McCullochForce2PerPowerInput = 500.3

Shawyer/PhtnRckt/Q = 0.05793
McCulloch1/PhtnRckt/Q = 0.1302
McCulloch2/PhtnRckt/Q =  0.01364



(* Shawyer Experimental *)
rfFrequency=2.45*10^9;
cavityLength=0.156;
bigDiameter=0.16;
smallDiameter=0.127546;
ShawyerDesignFactor = 0.497

power =  850   
Q = 5900

measured force = 16
ShawyerForce = 16.63
McCullochForce1 = 3.26
McCullochForce2 = 4.15

measured ForcePerPowerInput = 18.82
ShawyerForcePerPowerInput = 19.57
McCullochForce1PerPowerInput = 3.83
McCullochForce2PerPowerInput =4.88

Shawyer/PhtnRckt/Q = 0.9940
McCulloch1/PhtnRckt/Q = 0.1945
McCulloch2/PhtnRckt/Q = 0.2481



(* Shawyer Demo *)
rfFrequency=2.45*10^9;
cavityLength=0.345;
bigDiameter=0.28;
smallDiameter= 0.128853
ShawyerDesignFactor  = 0.844

power =  421 to 1200
Q = 45000

(measured force = 102.30 milliNewtons only reported for  421 watts, 243 milliNewtons/kW )

measured ForcePerPowerInput = 80 to 243
ShawyerForcePerPowerInput = 253.4
McCullochForce1PerPowerInput = 76.95
McCullochForce2PerPowerInput = 217.0

Shawyer/PhtnRckt/Q = 1.688
McCulloch1/PhtnRckt/Q = 0.5125
McCulloch2/PhtnRckt/Q = 1.445



All Brady cases have the following dimensions:

cavityLength=0.332;
bigDiameter=0.397;
smallDiameter=0.244;


(* Brady a *)
rfFrequency=1.9326*10^9;
ShawyerDesignFactor  =0.311969

power =   16.9 
Q = 7320

measured force =  0.0912
ShawyerForce = 0.2575
McCullochForce1 = 0.1011
McCullochForce2 =0.2164

measured ForcePerPowerInput = 5.396
ShawyerForcePerPowerInput = 15.24
McCullochForce1PerPowerInput = 5.982
McCullochForce2PerPowerInput =12.81

Shawyer/PhtnRckt/Q = 0.6239
McCulloch1/PhtnRckt/Q = 0.2449
McCulloch2/PhtnRckt/Q = 0.524384

(* Brady b *)   STATISTICAL OUTLIER
rfFrequency=1.9367*10^9;
ShawyerDesignFactor  = 0.310959

power = 16.7
Q =  18100

measured force = 0.0501
ShawyerForce = 0.6272
McCullochForce1 = 0.2465
McCullochForce2 =0.5289

measured ForcePerPowerInput = 3.000
ShawyerForcePerPowerInput = 37.56
McCullochForce1PerPowerInput = 14.76
McCullochForce2PerPowerInput =31.67

Shawyer/PhtnRckt/Q = 0.6219
McCulloch1/PhtnRckt/Q = 0.2444
McCulloch2/PhtnRckt/Q = 0.5244


  (* Brady c *)
rfFrequency = 1.8804*10^9;
ShawyerDesignFactor  = 0.325498

power = 2.6
Q = 22000

measured force = 0.05541
ShawyerForce = 0.1242
McCullochForce1 = 0.04805
McCullochForce2 = 0.1001

measured ForcePerPowerInput = 21.31
ShawyerForcePerPowerInput = 47.79
McCullochForce1PerPowerInput = 18.48
McCullochForce2PerPowerInput = 38.49

Shawyer/PhtnRckt/Q = 0.6510
McCulloch1/PhtnRckt/Q = 0.2517
McCulloch2/PhtnRckt/Q = 0.5244
« Last Edit: 10/28/2014 05:04 PM by Rodal »

Offline Rodal

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Re: EM Drive Developments
« Reply #2729 on: 10/28/2014 12:57 PM »
The above table for Cannae superconducting is based on the dimensions as noted, which at present are the best estimates (the drawing specifies that its dimensions are given in cm, one should take the inner cavity dimensions for the calculations).

See:  http://forum.nasaspaceflight.com/index.php?topic=29276.msg1277772#msg1277772

If anybody can contribute further, by correcting the 3 cm cavity height, such criticism is always strongly welcomed.  As usual I will correct accordingly and I will acknowledge and thank the person doing the correcting.
« Last Edit: 10/28/2014 01:09 PM by Rodal »

Offline Rodal

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Re: EM Drive Developments
« Reply #2730 on: 10/28/2014 01:02 PM »
Taking into account that the amplitude vs. frequency response is very nonlinear, and that the researchers don't quite know at what precise frequency the maximum amplitude takes place and they lack the precise equipment to keep the frequency steady at the peak amplitude, the prediction formulas do a pretty good job.

The Q ranges from ~5,900 to 1,100,000.  The power ranges from 2.6 watts to 1200 watts.
The cavity axial lengths range from 0.03 m to 0.345 m.
« Last Edit: 10/28/2014 01:05 PM by Rodal »

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #2731 on: 10/28/2014 01:05 PM »
Further analysis of the anomalous thrusts based on that picture is a waste of time.

A common tautology found in any investigation:

"Further analysis of ...(by anybody that thinks the investigation is a waste of time) ...is a waste of time"

Based only on the picture of the fictional dewar.  Not all investigations.

Sometimes I just flat out don't get it.

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #2732 on: 10/28/2014 01:07 PM »
Hey John could you take a look at this drawing please:

I did, and wrote a screed fifteen minutes ago, and fumble fingered the post, losing it in the well, aether.  'Tis only my time.

Short answer.  The drawing is poorly dimensioned, but graphically, the depth of that cavity is 1 cm.
Sometimes I just flat out don't get it.

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #2733 on: 10/28/2014 01:11 PM »
Oh yeah, I created a new universe inside a copper can too.

Now here's a copper can within which, I assure you, you will find a new universe...

Sometimes I just flat out don't get it.

Offline Rodal

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Re: EM Drive Developments
« Reply #2734 on: 10/28/2014 01:11 PM »
Hey John could you take a look at this drawing please:

I did, and wrote a screed fifteen minutes ago, and fumble fingered the post, losing it in the well, aether.  'Tis only my time.

Short answer.  The drawing is poorly dimensioned, but graphically, the depth of that cavity is 1 cm.

OK, great we have settled that.

Now please take a look at this picture.



The total cavity is formed by both cavities. So it is at least 1cm+1cm =2cm

But there are also the contributions of the straight vertical edges. Which are about 0.4cm+0.6cm=1cm Agree?

So the total cavity is 1cm+0.4cm+0.6cm+1cm = 3 cm
« Last Edit: 10/28/2014 01:12 PM by Rodal »

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #2735 on: 10/28/2014 01:22 PM »
@John and those believing nothing conclusive can come out of the data because of its sketchy nature, I'm sure we all understand that it might very well be the case that indeed nothing conclusive can come at this stage with data acquired (and released) so far.

Sorry.  I'm just another frustrated white american male.  I do appreciate your all's work.  Let's give the experimentors a big hand, ok?

« Last Edit: 10/28/2014 01:22 PM by JohnFornaro »
Sometimes I just flat out don't get it.

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #2736 on: 10/28/2014 01:28 PM »
So the total cavity is 1cm+0.4cm+0.6cm+1cm = 3 cm

Thinking the two halves woudl be the same, I'd guess 0.5 + 0.5 = 1 cm, but hey.

I suppose there's a band, not illustrated, which would "seal" the joint between the two fitments.
Sometimes I just flat out don't get it.

Offline Rodal

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Re: EM Drive Developments
« Reply #2737 on: 10/28/2014 01:36 PM »
So the total cavity is 1cm+0.4cm+0.6cm+1cm = 3 cm

Thinking the two halves woudl be the same, I'd guess 0.5 + 0.5 = 1 cm, but hey.

I suppose there's a band, not illustrated, which would "seal" the joint between the two fitments.

I don't quite see why would 1 cm would become 0.5 cm, unless they are mating.

It looks that you are assuming that one half is a male and the other half is a female and they mate with each other, but the picture does not show any mating.



Also you are not including the  vertical edges (unless you assumed that the straigth edges dissapear upon mating both halves): the picture shows no penetration of the vertical straight edge into the other half.

The picture shows no explicit mating.  The picture does not show any explicit penetration of one half into the other half.
« Last Edit: 10/28/2014 03:19 PM by Rodal »

Offline Ron Stahl

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Re: EM Drive Developments
« Reply #2738 on: 10/28/2014 02:25 PM »
I am starting to wonder if the info needed the most (predictive equations, measurements, frequencies) isn't hidden away by Non Disclosure Agreements.  Might account for the lack of later papers (after 2007) by Doctor White, and why getting other info is like pulling teeth.

There just doesn't seem to be all that much to most of these devices.  A competent machinist could probably build one in a weekend from scratch for not much more than beer money.  Oddly shaped and constructed microwave ovens basically.

Sonny told Pop Sci when they came for a visit that he was restrained by NDA, but there are long odds on that.  Who would have asked him to sign it?  (Apart from the outside work they did for Boeing, wich makes perfect sense.)  Rather he has likely asked others to so sign.  The real issue here is that Sonny can't patent anything since he didn't invent the stuff.  Best he can do is operate under trade secret status so you should not expect ever to get much detail about his setup.

BTW as we mentioned before, this cannot be done with a microwave oven magnetron.  It needs a continuous wave magnetron.  They're much more expensive, most often water cooled and not the kind of thing you can pick up on EBay for $25.  They draw several kW of power and if you mess up with one, they're fry the inside of your eyeballs in 3 seconds.  So this is  not as simple as it seems.

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Re: EM Drive Developments
« Reply #2739 on: 10/28/2014 02:47 PM »
So the total cavity is 1cm+0.4cm+0.6cm+1cm = 3 cm

Thinking the two halves woudl be the same, I'd guess 0.5 + 0.5 = 1 cm, but hey.

I suppose there's a band, not illustrated, which would "seal" the joint between the two fitments.

I don't quite see why would 1 cm would become 0.5 cm, unless they are mating.

It looks that you are assuming that one half is a male and the other half is a female and they mate with each other, but the picture does not show any mating.



Also you are not including the  vertical edges (unless you assumed that the straigth edges dissapear upon mating both halves): the picture shows no penetration of the vertical straight edge into the other half.

The picture shows no mating.  The picture does not show any penetration of one half into the other half.

I'm assuming this was tested with internal vacuum. Or was it just frozen air that was vaporized by RF energy?
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