Author Topic: EM Drive Developments - related to space flight applications - Thread 2  (Read 2172934 times)

Offline Mulletron

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Quote from: wembley
There is essentially a news blackout on the experimental side from NASA.

The problem is, if this drive really works, the defence implications are huge. Those in charge might feel it would not necessarily be a good idea to go public with it -- especially from the US perspective. Remember that 'Sputnik moment'?
Quote from: Mulletron
@wembley, do you have any specific info about why you think there is a news blackout?

Also, do you have any further verifiable information from this post: http://forum.nasaspaceflight.com/index.php?topic=29276.msg1265607#msg1265607 stating Shawyer stopped using a dielectric section?
Quote from: wembley
I been in contact with NASA on this and the lack of direct response has been marked. They will talk about the warp drive and other work, but will not even mention the EmDrive in their replies. It's as though they cannot speak its name...I also have it from other sources that NASA have requested that they do not discuss NASA's work in this area. If you can find any official NASA public comment on anything related to their EmDrive work I will be impressed!  It does look like a blackout to me.

The info about Shawyer not using dielectric section was in an email from the man himself.

Interesting to hear.

What happens if another country wheels a drive out, haven't others been working in this area?
It means an arms race, with the benefit being new tech making its way into the private sector eventually, as it usually does. I think our academic institutions and Nasa are being careful, either confirming a breakthrough or squashing a blunder.

....fixing all those quotes was a mess, did I screw them up?
« Last Edit: 01/21/2015 09:07 PM by Mulletron »
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Offline Star One

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So does that mean we shouldn't except to hear anything more from the US on this & if that's the case what does that mean for civil applications?

I don't believe they can prevent any public disclosure of undeniably working prototypes by the Chinese, in a few years (or months). So they probably are just buying some time for having a working version on our side by then.

That or someone on NASA became aware of the potential huge embarrassment this represents, and told all the guys off and ordered them to pretend it never happened.

But as H. White et al seem to be still working at NASA, I somewhat doubt it's a case of disowning a blunder. Or at least, I hope so.
It could be that the decision, assuming it does work, on what to say and what not to say has gone right the way up the chain of command literally to the very top and in the meantime the blackout is put in place.

This might sound odd but perhaps it's for the best that for now this stays outside of the mainstream of public awareness.

Offline Mulletron

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So does that mean we shouldn't except to hear anything more from the US on this & if that's the case what does that mean for civil applications?

I don't believe they can prevent any public disclosure of undeniably working prototypes by the Chinese, in a few years (or months). So they probably are just buying some time for having a working version on our side by then.

That or someone on NASA became aware of the potential huge embarrassment this represents, and told all the guys off and ordered them to pretend it never happened.

But as H. White et al seem to be still working at NASA, I somewhat doubt it's a case of disowning a blunder. Or at least, I hope so.
Yep you nailed it....... This is TOO public so the truth will have to come and come soon. This isn't your typical flash in the pan news story. The potential worth of this kind of discovery is priceless, on the order of Newton and Einstein. Or just a big series of unfortunate mistakes.
Challenge your preconceptions, or they will challenge you. - Velik

Online Stormbringer

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So does that mean we shouldn't except to hear anything more from the US on this & if that's the case what does that mean for civil applications?

I don't believe they can prevent any public disclosure of undeniably working prototypes by the Chinese, in a few years (or months). So they probably are just buying some time for having a working version on our side by then.

That or someone on NASA became aware of the potential huge embarrassment this represents, and told all the guys off and ordered them to pretend it never happened.

But as H. White et al seem to be still working at NASA, I somewhat doubt it's a case of disowning a blunder. Or at least, I hope so.
It could be that the decision, assuming it does work, on what to say and what not to say has gone right the way up the chain of command literally to the very top and in the meantime the blackout is put in place.

This might sound odd but perhaps it's for the best that for now this stays outside of the mainstream of public awareness.
only if this thing can go hyper velocity or relativistic velocity in a flight profile that makes it useful as a weapon of mass destruction. so far the most optimistic projection by Dr White would make it have to fly for over twelve days and then turn around and come back to make it into a WMD. that's not really a realistic flight profile for a sneak attack weapon.
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Offline DIYFAN

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It could be that the decision, assuming it does work, on what to say and what not to say has gone right the way up the chain of command literally to the very top and in the meantime the blackout is put in place.

This might sound odd but perhaps it's for the best that for now this stays outside of the mainstream of public awareness.

Assuming there really is a blackout from NASA (not convinced of that yet), your scenario seems plausible.  The problem is, opaque governments are becoming a thing of the past.  The Internet, and its communities, are pressuring governments to be more open and transparent.  Secrecy, even in the name of national security, can sometimes backfire, particularly when certain technologies have the capability of lifting people of the world out of poverty.  In other words, withholding technological progress in the civilian space can result in a moral failure.

Offline Asteroza

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So does that mean we shouldn't except to hear anything more from the US on this & if that's the case what does that mean for civil applications?

I don't believe they can prevent any public disclosure of undeniably working prototypes by the Chinese, in a few years (or months). So they probably are just buying some time for having a working version on our side by then.

That or someone on NASA became aware of the potential huge embarrassment this represents, and told all the guys off and ordered them to pretend it never happened.

But as H. White et al seem to be still working at NASA, I somewhat doubt it's a case of disowning a blunder. Or at least, I hope so.
It could be that the decision, assuming it does work, on what to say and what not to say has gone right the way up the chain of command literally to the very top and in the meantime the blackout is put in place.

This might sound odd but perhaps it's for the best that for now this stays outside of the mainstream of public awareness.
only if this thing can go hyper velocity or relativistic velocity in a flight profile that makes it useful as a weapon of mass destruction. so far the most optimistic projection by Dr White would make it have to fly for over twelve days and then turn around and come back to make it into a WMD. that's not really a realistic flight profile for a sneak attack weapon.

Well, if it works, then parking a second strike kinetic weapon package at earth-sun L4/L5 is feasible (hell, earth-moon L2 would make the package immune from terrestrial laser attack). This IS the US military we're talking about, who dreamed up Project Horizon to bomb the earth from a moonbase, and that was with a 3 day lag using chemical propulsion. Added fun is using an expendable electrodynamic tether as a power source as you approach earth, since you only need high relative speed at impact (drop into a counterorbit).

Actually, I wonder how applicable that would be, using an ED tether as a power source for orbital capture ops, as a possible alternative to aerocapture...

Offline tchernik

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Well, if it works, then parking a second strike kinetic weapon package at earth-sun L4/L5 is feasible (hell, earth-moon L2 would make the package immune from terrestrial laser attack). This IS the US military we're talking about, who dreamed up Project Horizon to bomb the earth from a moonbase, and that was with a 3 day lag using chemical propulsion. Added fun is using an expendable electrodynamic tether as a power source as you approach earth, since you only need high relative speed at impact (drop into a counterorbit).

Actually, I wonder how applicable that would be, using an ED tether as a power source for orbital capture ops, as a possible alternative to aerocapture...

You know, despite the well meaning attempts to place this within the known laws of physics, and telling us this works and respects conservation of momentum (and energy), I'm still not convinced how that could be. Rockets respect conservation of momentum and energy by losing mass (and thus energy) in greater amounts than they gain by expelling that mass. These things don't have any clear way to remember how much energy they have spent, and what relative maximum velocity they can reach in order to not be "overunity". No wonder they face very strong skepticism.

But leaving that part out. Even assuming they are limited in speed, they still seem capable of gathering a fair bit of kinetic energy (tens of kms per second as per a previous post).

Thus the geopolitical impact of this technology being real is evident if you think about it a little.

In the short term, endless autonomy in terms of thrust and re-positioning would completely change the rules of engagement for spy satellites and anti-satellite weapons. You can have limitless observation capabilities and limitless loitering, following, attacking (and dodging) capabilities too. War bots in orbit could finally fulfill Ronald Reagan's dreams for war in space. And not just that.

Even very slight accelerations (as reported by Brady, White et al) with preposterously limited top speeds, they can serve for pushing and placing dormant kinetic bombs far away from Earth, beyond the reach of any feasible enemy's detection or attack; and they would also serve for bringing them back to Earth at their maker's command, for landing at any desired spot, producing nearly any desired amount of damage.

While all of us sit here on Earth, sharing the same biosphere and the same rock under our feet, the development and availability of that weaponry would result in an aggravated and somewhat madder version of MAD. Because even if you could be attacked in secret from any direction, you can very well threaten to respond by attacking all your potential enemies with nuclear or kinetic nastiness, ruining the game and the fun for all your potential attackers.

But if you have parties/adversaries living in space, could you threaten to crack all the planets in the Solar System?, or all the artificial habitats floating in the space between?

Removing the speed limitations (thus conservation of energy) only makes things worse, making it feasible to have interstellar adversaries sending relativistic missiles to you. Those have no way to be stopped and even less, any way to provide adequate or proportionate response (you and all around you sharing the same planet would simply be dead).

Offline DIYFAN

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Thus the geopolitical impact of this technology being real is evident if you think about it a little.

In the short term, endless autonomy in terms of thrust and re-positioning would completely change the rules of engagement for spy satellites and anti-satellite weapons. You can have limitless observation capabilities and limitless loitering, following, attacking (and dodging) capabilities too. War bots in orbit could finally fulfill Ronald Reagan's dreams for war in space. And not just that.

Even very slight accelerations (as reported by Brady, White et al) with preposterously limited top speeds, they can serve for pushing and placing dormant kinetic bombs far away from Earth, beyond the reach of any feasible enemy's detection or attack; and they would also serve for bringing them back to Earth at their maker's command, for landing at any desired spot, producing nearly any desired amount of damage.

While all of us sit here on Earth, sharing the same biosphere and the same rock under our feet, the development and availability of that weaponry would result in an aggravated and somewhat madder version of MAD. Because even if you could be attacked in secret from any direction, you can very well threaten to respond by attacking all your potential enemies with nuclear or kinetic nastiness, ruining the game and the fun for all your potential attackers.

But if you have parties/adversaries living in space, could you threaten to crack all the planets in the Solar System?, or all the artificial habitats floating in the space between?

Removing the speed limitations (thus conservation of energy) only makes things worse, making it feasible to have interstellar adversaries sending relativistic missiles to you. Those have no way to be stopped and even less, any way to provide adequate or proportionate response (you and all around you sharing the same planet would simply be dead).

I agree that the geopolitical impact of this technology being real is evident.  Consider, however, that the geopolitical impact might be far more positive than supposed.  If asteroids can be mined economically using this technology, can you imagine the impact?  Mining on Earth could therefore be reduced, thereby reducing negative impacts on Earth's ecosystem. 

If sufficient lift can be achieved, freights and shipping become far more economical such that providing goods to the poorest of the world to meet the basic necessities of life all of the sudden becomes quite feasible. 

Wars and poverty often go hand-in-hand.  If you can uplift and help a society become more self-sufficient and civilized, the trajectory toward war diminishes.  Even if this technology (assuming it works) is used for defense or purposes of war, the mutually assured destruction principal would apply equally well here as it would with other dual purpose technologies.   
« Last Edit: 01/22/2015 03:57 AM by DIYFAN »

Offline wembley

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So does that mean we shouldn't except to hear anything more from the US on this & if that's the case what does that mean for civil applications?

I don't believe they can prevent any public disclosure of undeniably working prototypes by the Chinese, in a few years (or months). So they probably are just buying some time for having a working version on our side by then.



The Chinese will not go public. They have had a fairly tight clampdown for a couple of years now, with the only evidence being odd scientific papers.  They don't want anyone else getting a lead on them either.

Offline Rodal

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...Rockets respect conservation of momentum and energy by losing mass (and thus energy) in greater amounts than they gain by expelling that mass. These things don't have any clear way to remember how much energy they have spent, and what relative maximum velocity they can reach in order to not be "overunity"....

Just like one needs to take into account the energy/momentum of ejected mass from a classical rocket (or injected into and ejected from a turbojet), also for an EM Drive the energy and momentum of the total open system has to be taken into account to reach any conclusions on velocity limitations:

*for Dr.McCulloch's EM Drive theory, the energy/momentum of the radiated Unruh radiation has to be taken into account.  According to Dr. McCulloch's theory, there is Unruh radiation being emitted from the EM Drive, that Unruh radiation has energy/momentum, and it is responsible for conservation of momentum. 

*for EM Drive theories advocating interaction with the Quantum Vacuum (Dr. White's or the theories considered by @Mulletron) the energy/momentum of the involved Quantum Vacuum has to be taken into account.  An example would be given by Dr.White's analogy of the propeller in a submarine: the energy/momentum of the water propelled by the propeller has to be taken into account.

*ditto for EM Drive theories advocating coupling between electromagnetism and gravitational forces, or theories advocating coupling with Dark Matter, or any other theories explaining conservation of momentum of the EM Drive: the energy/momentum of the coupled field also needs to be taken into account

Thus my conclusion is that Joosten and White's "paradox" analysis for the EM Drive (Appendix A of  "Human Outer Solar System Exploration via Q-Thruster Technology" by B. Kent Joosten and Harold G. “Sonny” White, http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140013174.pdf ) is incorrect/incomplete because they failed to take into account the energy/momentum of the involved Quantum Vacuum (which they advocate as the reason for conservation of momentum yet they fail to take into account when they perform the kinetic energy constraint).  Actually Dr. White in the same article shows how a classical ion rocket suffers the same "paradox" if one fails to take into account the energy/momentum of the ejected propellant.

No, the EM Drives do NOT need to remember how much energy they have spent, and what relative maximum velocity they can reach in order to not be "overunity", that "memory" would be a requirement only if one disregards conservation of momentum, which none of us is prepared to do, because it violates a basic law of physics. 

If the EM drive conserves momentum, for example, by interacting with the QuantumVacuum, we have an open system where momentum will be flowing in or out of the cavity, and therefore the open system should be taken into account in the conservation of energy in order to arrive at a satisfactory answer concerning any velocity limitation.


« Last Edit: 01/22/2015 03:57 PM by Rodal »

Offline Star One

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So does that mean we shouldn't except to hear anything more from the US on this & if that's the case what does that mean for civil applications?

I don't believe they can prevent any public disclosure of undeniably working prototypes by the Chinese, in a few years (or months). So they probably are just buying some time for having a working version on our side by then.



The Chinese will not go public. They have had a fairly tight clampdown for a couple of years now, with the only evidence being odd scientific papers.  They don't want anyone else getting a lead on them either.

Sounding like a game of Texas Hold' em between them and the U.S. Wonder if there are any other players of substance in this game?
« Last Edit: 01/22/2015 01:45 PM by Star One »

Offline Cinder

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Really hoping that discussing such subjective political prospects and other implications of an as yet very theoretical space propulsion technology, is not going to get this thread locked for good..
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Offline Rodal

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Really hoping that discussing such subjective political prospects and other implications of an as yet very theoretical space propulsion technology, is not going to get this thread locked for good..
1) As explained here http://forum.nasaspaceflight.com/index.php?topic=29276.msg1301657#msg1301657, the previous long thread (which due to its extreme length would have been eventually locked to start a new thread anyway) was locked because of personal attacks and "stupid" and "pointless" posts "that did not feel like this site's subject matter." Specifically, posts (sometimes involving ad hominem attacks) dealing with Mach-Effect Piezoelectric experiments and theory (which already had dedicated threads to deal specifically with that topic) instead of the thread's subject: (Microwave ) EM Drive developments.

2) Political ramifications of space flight applications (for example NASA's rocket developments, SpaceX developments, or Advanced Concepts like Vasimir development or Fusion Power technology) are routinely discussed in many threads of NASA's SpaceFlight Forum, why shouldn't political ramifications of (Microwave) EM Drive space flight applications be discussed as well? (as long of course as they do not contain ad hominem attacks).

3) This EM Drive technology has now been repeatedly tested (experimentally ) at NASA in the USA, in the UK and in China.  The experimental results of these measurements reportedly produce thrust/PowerInput that are within practical SpaceFlight Applications.  Such spaceflight applications have been discussed in several reports by NASA and in this thread.  So, assuming that the experimental results at NASA, UK and China are not all artifacts, the subject being discussed here is not just a theory (unlike some threads in the "Advanced Concepts" section of the NASA SpaceFlight Forum that discuss topics that are much further away from SpaceFlight applications).
« Last Edit: 01/22/2015 07:13 PM by Rodal »

Offline Star One

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@Rodal tested in the UK, never knew that?

Who was carrying out those experiments?
« Last Edit: 01/22/2015 06:52 PM by Star One »

Online Stormbringer

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@Rodal tested in the UK, never knew that?

Who was carrying out those experiments?
Isn't Shawyer a UK native?
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Offline Rodal

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@Rodal tested in the UK, never knew that?

Who was carrying out those experiments?

Satellite Propulsion Research Ltd (SPR Ltd), a UK based company, with partial funding from the UK government for some of their tests.  See http://www.emdrive.com/
« Last Edit: 01/22/2015 07:46 PM by Rodal »

Offline Cinder

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why shouldn't political ramifications of (Microwave) EM Drive space flight applications be discussed as well?
I don't mind them myself.  But I got the possibly mistaken impression (e.g. people actually asking for this to be locked even after thread v.2) that they put the discussion thread too close to or beyond this website's tolerances.  My bad.

Seeing such a thorough crunching thru the uncertainties of such an advanced and frankly just plain cool potential technology, IMHO is too excellent to lose.  Even if EM Drives all turn out to be nothing, the process of making sense of it as detailed in these two threads is exemplary.
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Offline Rodal

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why shouldn't political ramifications of (Microwave) EM Drive space flight applications be discussed as well?
I don't mind them myself.  But I got the possibly mistaken impression (e.g. people actually asking for this to be locked even after thread v.2) that they put the discussion thread too close to or beyond this website's tolerances.  My bad.

Seeing such a thorough crunching thru the uncertainties of such an advanced and frankly just plain cool potential technology, IMHO is too excellent to lose.  Even if EM Drives all turn out to be nothing, the process of making sense of it as detailed in these two threads is exemplary.
Happy to hear that you share our excitement of the potential of propellant-less space-propulsion technology  :)
« Last Edit: 01/22/2015 08:10 PM by Rodal »

Offline Cinder

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The way you guys systematically work every scenario to its end, leaving no stone unturned is really awesome.  Ok, I'll let signal/noise go back to normal now.
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Online aero

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@Notsosureofit
This is a little information regarding the effect of the dielectric on resonance frequency in a cylindrical cavity.
Using the Wikipedia equations for resonance of a cylindrical cavity, J'1(1) = 1.8412, and L = c/2.45E9/s, with p = 1, I calculated frequency to be 2.45 GHz when R = 0.0377449 m. I think this is the TE1,1,1 mode.

I then modelled this cylindrical cavity in meep, the FDTD software, with a drive frequency of 2.45E9 Hz, electrical. On running the software with the cavity model empty (containing vacuum, no dielectric), Harminv calculated resonance to be 1.85058E+009 GHz. Q-factor was 484476.647518797. I don't know why frequency is not 2.45 GHz but it isn't.

I then inserted a PE dielectric with a constant of 1.76, length of 20% of the cavity length, radius = cavity radius. The dielectric was against one end of the cavity. I ran this in meep and Harminv calculated a resonance frequency of 1.70036E+009 and 3.67196E+009 Hz. Q-factors of 342650.708941864 and 280142.928092836.

Pardon all of the digits. Result is,
Resonate frequency = 1850. MHz, Q = 4.8 E+05 with no dielectric
Resonate frequency = 1700. MHz, Q = 3.4 E+05 with 20 % cavity filled with dielectric, constant 1.76.
And another resonant mode at 3671 MHz, Q = 2.8 E+05.

A corresponding second mode may have existed for the empty cavity. I don't know as I had to extend the frequency band search to find the 1.7 GHz frequency which extended the band upward as well as downward.

In any case, these numbers are one way to look at the effect of the dielectric within the cavity. I did make an effort to change the cavity parameters in order to hold the resonant frequency constant. That's to hard.

I would be curious to know if anyone can explain why the difference between the Wikipedia formula calculation of resonant frequency and the resonant frequency obtained by integrating Maxwell's equations in the time domain then doing Fourier analysis to calculate the resonant frequencies. In a nutshell, meep excites the cavity with Gaussian noise across the search band, waits for the noise to die down, then extracts the 100 strongest frequencies, dropping those for which Q is less than 50. It reports those that remain.
« Last Edit: 01/23/2015 12:19 AM by aero »
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