Tiny thrust, but no fuel required

Hope it pans out:

Anomalous Thrust Production from an RF Test Device
Measured on a Low-Thrust Torsion Pendulum

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140006052.pdf

https://ntrs.nasa.gov/search.jsp?R=20140006052

Excerpt:

This paper describes the eight-day August 2013 test campaign designed to investigate and demonstrate
viability of using classical magnetoplasmadynamics to obtain a propulsive momentum transfer via the
quantum vacuum virtual plasma.

Test results indicate that the RF resonant cavity thruster design, which is unique as an electric propulsion
device, is producing a force that is not attributable to any classical electromagnetic phenomenon and
therefore is potentially demonstrating an interaction with the quantum vacuum virtual plasma.

NASA tested an "impossible" space engine and it somehow worked

https://www.theverge.com/2014/8/1/5959637/nasa-cannae-drive-tests-have-promising-results

Excerpt:

The idea is that microwaves bouncing from end-to-end of a specially designed, unevenly-shaped container can create a difference in radiation pressure, causing thrust to be exerted toward the larger end of the container. A similar type of technology called an EmDrive has been demonstrated to work in small scale trials by Chinese and Argentine scientists.

While the amount of thrust generated in these NASA's tests was lower than previous trials — between 30 and 50 micronewtons, way less than even the weight of an iPhone, as Nova points out — the fact that any thrust whatsoever is generated without an onboard source of fuel seems to violate the conservation of momentum, a bedrock in the laws of physics.

On the mentioned EmDrive, from Wikipedia:

https://en.wikipedia.org/wiki/EmDrive

The [EmDrive] device and its mode of operation are highly controversial. As of 2014, it is still not proven if the EmDrive is a genuinely new propulsion method; a misinterpretation of spurious effects mixed with mathematical errors; or a scam. The proposed theory immediately received virulent criticism because it seems to violate basic Newtonian laws of physics, notably conservation of momentum,[10][11] though the inventor insists on the contrary.[12] Whatever it be, peer reviewed independent replication has been provided by Chinese researchers from the Northwestern Polytechnic University on both mathematical and experimental grounds.[4][13] in 2008,[14] 2010,[15] 2012,[16] and 2013.[17] NASA has followed suit with these claims by a validation of the experiment, replicated in Eagleworks Laboratories at the Johnson Space Center.[9][18]

Crookes Radiometer. https://en.wikipedia.org/wiki/Crookes_radiometer




Solar Sails. https://en.wikipedia.org/wiki/Solar_sail https://science.howstuffworks.com/solar-sail.htm






Space is a vacuum, there's not much gas there. The tests at NASA were conducted in their electric propulsion test chamber, but instead of performing the test at a space level vacuum, they simple closed the door and left the air in the chamber.

What these "rocket scientists" most likely observed is not rocket science, but ignorance of physics. IMO they converted RF energy into heat and the heat transferred into the air within the device which move out of the microwave cavity providing a thrust...... If it's supposed to be a fuel less thruster, you have to remove the air so there is no fluid to heat..... The device also has a microwave generator that consumes a lot of power to generate extremely low thrust so by any account it is extremely inefficient, which has been the bane of all "sifi" electric propulsion devices......

Now solar sails are a truly "fuel less" device since it relies on photon momentum and doesn't carry the solar power source. The major problem here is the reflectivity of the sail, and the requirement to have very large, and extremely light weight and thin structures. Some early Mariner planetary probes used their solar panels as solar sails to augment delta-v by going close to the sun, but solar energy falls off as I/r2 so the farther away from the sun, the less thrust so even if you could make an efficient system, interstellar missions would be a stretch.

Stay tuned....

Bob

bobkrech said:

Space is a vacuum, there's not much gas there. The tests at NASA were conducted in their electric propulsion test chamber, but instead of performing the test at a space level vacuum, they simple closed the door and left the air in the chamber.

Click to expand...

I thought for sure you must be mistaken, because it seems obvious that any gas at all in the chamber could be what the device is pushing against, not the "quantum vacuum virtual plasma." But I read tha article, and sure enough, it was in a vacuum chamber, with the door closed, but at atmospheric pressure. It's a vacuum chamber! Suck the air out and try it again!

ThirstyBarbarian said:

I thought for sure you must be mistaken, because it seems obvious that any gas at all in the chamber could be what the device is pushing against, not the "quantum vacuum virtual plasma." But I read tha article, and sure enough, it was in a vacuum chamber, with the door closed, but at atmospheric pressure. It's a vacuum chamber! Suck the air out and try it again!

Click to expand...

You're right! I saw vacuum chamber and assumed they used it as such! Unfreakingbelievable! They apparently just used it to prevent "thrust" readings due to tiny drafts.

More on the device:

Quantum vacuum plasma thruster

https://en.wikipedia.org/wiki/Quantum_vacuum_plasma_thruster

Excerpt (which brings up the question, "So, why aren't they testing it in a vacuum then?!")

Theory of operation

The research team claims the "Q-thruster" utilizes the quantum vacuum fluctuations of empty space as a "propellant". The existence of quantum vacuum fluctuations is not disputed, because experiments with the quantum mechanical Casimir effect have unambiguously demonstrated that quantum vacuum fluctuations do exist. What remains to be proven is that these fluctuations can be utilized for this practical purpose.[4]

The Q-thruster operates on the principles of magnetohydrodynamics (MHD), the same principles and equations of motion used by a conventional plasma thruster. The difference is that the Q-thruster uses the atomic particles spontaneously produced by quantum vacuum fluctuations as its propellant. The atomic particles produced by the fluctuations are subsequently electrically ionized to form a plasma. The now electrically charged plasma is then exposed to a crossed electric and magnetic field, inducing a force on the particles of the plasma in the E×B direction, which is orthogonal to the applied fields. The Q-thruster would not technically be a reactionless drive, because it expels the plasma and thus produces force on the spacecraft in the opposite direction, like a conventional rocket engine. However, this action does not require the spacecraft to carry any propellant. This theory suggests much higher specific impulses are available for Q-thrusters, because they only consume electrical power and thus are limited only by their power supply's energy storage densities. Preliminary test results suggest thrust levels of between 1000–4000 μN; specific force performance of 0.1 N/kW, and an equivalent specific impulse of ~1x1012 s.

The other telling thing is that the "test article" they made (that wasn't supposed to produce thrust) also worked. If the placebo works as well as the drug you're testing .....

-- Roger

jadebox said:

The other telling thing is that the "test article" they made (that wasn't supposed to produce thrust) also worked. If the placebo works as well as the drug you're testing .....

-- Roger

Click to expand...

It's hard to believe that published work that's a product of people working at NASA's Lyndon B. Johnson Space Center could be so easily discernible as erroneous and not be instantly and vociferously discredited by peers, so I have to wonder if we're missing something. I'm going to see if I can find an email address for one or more of these guys and ask them why they aren't testing in a vacuum.

The PDF I linked to above is just the abstract even though it was labeled as "full-text." Here's a link to the full paper whihc I don't have access to. It was apparently presented at the 50th AIAA/ASME/SAE/ASEE Joint Propulsion Conference this July :

https://arc.aiaa.org/doi/abs/10.2514/6.2014-4029

Winston said:

... so I have to wonder if we're missing something.

Click to expand...

Definitely possible. It doesn't seem like something they would overlook, so it might be something we aren't understanding.

This is s super interesting idea. Even in a vacuum, there are particles that spontaneously pop out of the vacuum and almost immediately disappear back into it. So the idea is that you do not have to bring the reaction mass with you --- you are thrusting against these virtual particles that appear inside the chamber before they disappear again. Amazing (if true!).

Winston said:

It's hard to believe that published work that's a product of people working at NASA's Lyndon B. Johnson Space Center could be so easily discernible as erroneous and not be instantly and vociferously discredited by peers, so I have to wonder if we're missing something. I'm going to see if I can find an email address for one or more of these guys and ask them why they aren't testing in a vacuum.

Click to expand...

I'm not sure there's enough "there" there to elicit a response from the scientific community - at least not until something is submitted to and published in a peer-review journal.

Testing in a vacuum might show that the device doesn't really work. But, I suspect that it's directionally emitting heat or radio waves or it's creating a magnetic field or whatever, so it would still work in a vacuum (just not by swimming through the sea of quantum foam as claimed).

-- Roger

jadebox said:

I'm not sure there's enough "there" there to elicit a response from the scientific community - at least not until something is submitted to and published in a peer-review journal.

Testing in a vacuum might show that the device doesn't really work. But, I suspect that it's directionally emitting heat or radio waves or it's creating a magnetic field or whatever, so it would still work in a vacuum (just not by swimming through the sea of quantum foam as claimed).

-- Roger

Click to expand...

This is the third time the effect has appeared to have been verified by experiment. This paper was just presented in July and I assume the others were already published and peer reviewed from what I've been reading elsewhere. That's what inspired the NASA test. Their goal:

"This paper will not address the physics of the quantum vacuum plasma thruster, but instead will describe the test integration, test operations, and the results obtained from the test campaign."

There's a lengthy, very interesting and informed discussion of this on the aRocket mailing list.

Here's one post from aRocket:

I bought the paper. I personally don't care about the physics of how it works YET.

All I care about is verifying if it works.
So I am gonna build one.
Here is where yall come in.

Let us define what would be a two factor test for this. I want two high accuracy sensors to measure force. I am thinking a diaphragm backed by an ultra high accuracy pizeo pressure transducer, an lvdt to measure displament against the diaphragm and possibly a laser interferometer for measuring distance.

Background on me: I work at spacex, used to work at xcor, I live in a giant warehouse with three phase power. I am on first name basis with half the machine shops in los angeles. I build test systems everyday all day. Never done microwaves before but I am a quick learner.

What I need from the people on this list is help on design for an ultra sensitive verification system. Then I will start a kickstarter, collect the fifty grand or so from the cloud, and build the thing. I will build it in a portable self contained unit. I will run the first batch of experiments.

If there are positive results, I will freely hand it off to the first university that wants to play with it, and so on.
If there are negative results, I want to make sure I am the one to put a bullet in this things head.

Why do I want to do this? This would change the entire game as far as mars colonization and settlement is concerned. Also, I have many of the required skills to build test and verification equipment, and I am
perfectly willing to accept a negative result.

If anyone wants to team up, I am based out of los angeles.

Here is what I need
1. A primary way to verify operation or non operation of the device, by
direct force measument.
2. A secondary indirect system to verify the device.
3. A tertiary analog system to rule out electro magnetic interference.
4. An electrical engineer to help
5. An RF engineer to help. Jb plz
6. Money. Which I will try to kick start cloudfund after I work out a
budget for this.

Goal is to have a running test bed by January.

The paper is pretty clear on expemient setup. If we triple down on verification systems, I think we can nail this to a wall, one way or another.

Someone who seems to know a lot talking about it on Reddit:

https://www.reddit.com/user/dalovindj

His optimism apparently comes from "discussing it with people who attended the presentation and have read the paper."

And a nice article on Wired.UK:

https://www.wired.co.uk/news/archive/2014-07/31/nasa-validates-impossible-space-drive

that contains this relevant comment:

"...it's fair to assume that the results will be picked over very closely indeed, like CERN's anomalous faster-than-light neutrinos. The neutrino issue was cleared up fairly quickly, but given that this appears to be at least the third independent propellant-less thruster to work in tests, the anomalous thrust may prove much harder to explain away."

A FAQ on the very general principles involved:

https://emdrive.com/faq.html

Theory is nice, however an incontrovertible experimental demonstration of a practical system has not been conducted.

Remember cold fusion? Amazingly sloppy experimental work, but it duped many......



Bob

Winston said:

The PDF I linked to above is just the abstract even though it was labeled as "full-text." Here's a link to the full paper whihc I don't have access to. It was apparently presented at the 50th AIAA/ASME/SAE/ASEE Joint Propulsion Conference this July :

https://arc.aiaa.org/doi/abs/10.2514/6.2014-4029

Click to expand...

Hi, here is a link to the full text:
https://www.libertariannews.org/wp-...ustProductionFromanRFTestDevice-BradyEtAl.pdf

I've never understood how you could get something for nothing with physics. You can't cheat The House.

I've never seen anyone "pull a fast one", yet.

Greg

bobkrech said:

Theory is nice, however an incontrovertible experimental demonstration of a practical system has not been conducted.

Remember cold fusion? Amazingly sloppy experimental work, but it duped many......

View attachment 179777

Bob

Click to expand...

Bob,

When did you find time to pose for that poster?

Kenn

From what I have read a good peer review has not been done and that there is room for error in the measurements. I would get more excited when the experiment is widely accepted.

GregGleason said:

I've never understood how you could get something for nothing with physics. You can't cheat The House.

I've never seen anyone "pull a fast one", yet.

Greg

Click to expand...

At least as I understand it, you aren't really getting something for nothing with this. You still have to put energy into it, so it is not like you are getting energy for free. Some of the articles are saying the motor appears to violate conservation of momentum, but that's not really true either. It's not really a reactionless motor. The motor is pushing against a reaction mass, but that mass just disappears a few nanoseconds after you push on it, so no "exhaust" actually exits the motor, and so it appears to be reactionless. Anyway, I'm not saying I believe this thing really works, but that's how I understand it is supposed to work.

aerostadt said:

From what I have read a good peer review has not been done and that there is room for error in the measurements. I would get more excited when the experiment is widely accepted.

Click to expand...

They should launch one into orbit and see if it can maneuver. That would pretty much prove it.

From the aRocket mailing list, this guy has major issues with it and he was at the conference and has read the paper:

I was actually at that conference; didn't want to comment until I had a chance to read the paper, but now I have so here goes:

The team appears to have used a standard NASA-Lewis torsion balance thrust stand. That thrust stand, which I have used extensively, is good to about +/- 10 microNewtons when used in the steady-state mode by an expert team. There is a resonant mode (look for a paper by Lake and Dulligan) that can get down to +/- 1 uN or better, but that isn't what was used here.

Nor does the team that did this work appear to be thrust-stand experts. There is relatively little discussion of that aspect of their work, and what there is suggests that they did some things right (e.g. comparison to a ballast load to rule out interference from the power supply) and some things wrong (e.g. only a single-point calibration). They do not cite a reference to their thrust measurement technique, they do not give acknowledgement to any of the technicians, and a quick literature search of their prior work does not suggest great experience with the NASA-Lewis torsion balance thrust stand. Absent such expertise, or even the recognition that such expertise is necessary, errors of several tens of microNewtons are likely and hundreds of microNewtons are not implausible.

One thing they unambiguously did right, was to test the null-hypothesis model of their "Cannae" thruster. Theory says that that with the asymmetric groves you get ~10,000 microNewtons of thrust from 28 Watts of electric power and without the groves you get zero thrust. They tested both, on a thrust stand with error bars of a few tens of microNewtons, and got ~50 microNewtons of indicated thrust.

And made essentially no mention of this ever again, except to say "We got Thrust! Yay Us!".

Their subsequent testing of the truncated-cone thruster conspicuously failed to make use of a null-hypothesis model. After repeatedly showing about the same (lack of) performance as the "Cannae" thruster in its first two operating modes, they conducted one single test of the truncated-cone thruster in a third operating mode, demonstrated a fivefold increase in thrust-power, and found that time and facility limitations meant they had to terminate the experiments.

Finally, they put forth a batch of conclusions that are entirely unsupported by their own experimental data. It would have been bad enough to have reported the single anomalously high truncated-cone data point as the baseline and buried the null-hypothesis results. Worse, is reporting only the Chinese experimental results (nearly two orders of magnitude better than their own) and the theoretical calculations which they did not perform and did explicitly disclaim as beyond the scope of their paper, note that theory and experiment (other people's) indicate a thrust-power ratio of 0.4 N/kW, and proclaiming, "...and we also measured (mumble) thrust, so it's all true and we can have manned missions to the outer solar system any time now!"

They measured experimental error, and nothing more. And they set the bar so low, with such implied authority, that we can now look forward to years of dueling claims of "I built an EMdrive out of spare parts and put it on a thrust stand I had lying around, and got microNewtons of thrust just like NASA!", "So did I, and I got nothing at all!" Did so, did not, ad infinitum.

If theory and Chinese experiment really do validate claims of 0.4 N/kW, then you really can build an enclosed metal box (batteries in the box, to deal with the power-supply interactions Henry correctly notes) that
will visibly tilt a straight hanging pendulum. Do that, and get back to us.

Oh, and if you can build a reactionless thruster with a thrust-power ratio of 0.4 N/kW and can't think of anything better to do with it than fly to Uranus, you are an insanely myopic space cadet. I will leave it as an exercise to the student how one would incorporate such devices into a perpetual motion machine capable of providing clean, free energy on a massive scale. It isn't trivially easy, but it is almost certainly worth doing long before you build spaceships - and this was presented at a "Propulsion and Energy" conference, so it probably would have been worth mentioning.

Well, except for the fact that the Energy attendees would have been more merciless in their heckling; there's a long tradition of tolerance in the "future flight" sessions of the AIAA Propulsion conferences.

bobkrech said:

Theory is nice, however an incontrovertible experimental demonstration of a practical system has not been conducted.

Remember cold fusion? Amazingly sloppy experimental work, but it duped many......

View attachment 179777

Bob

Click to expand...

Yes, I do. Such a shame it didn't pan out. This, too, may cause some very red faces at NASA because of the very widespread sensational headlines based upon a possibly flawed experiment as critiqued in the aRocket post I just re-posted here.

Winston said:

... build an enclosed metal box (batteries in the box, to deal with the power-supply interactions Henry correctly notes) that
will visibly tilt a straight hanging pendulum. Do that, and get back to us.

Click to expand...

This is basically it right here.

ThirstyBarbarian said:

At least as I understand it, you aren't really getting something for nothing with this. You still have to put energy into it, so it is not like you are getting energy for free. Some of the articles are saying the motor appears to violate conservation of momentum, but that's not really true either. It's not really a reactionless motor. The motor is pushing against a reaction mass, but that mass just disappears a few nanoseconds after you push on it, so no "exhaust" actually exits the motor, and so it appears to be reactionless. Anyway, I'm not saying I believe this thing really works, but that's how I understand it is supposed to work.

Click to expand...

It seems to me that if this engine can do what the claims say it can and if it is doing it by the principles stated; then is this not just one step away from “Vacuum Energy” sometimes referred to as “Zero Point” energy?

Slightly reminesent of the fictional drive unit used in G. Harry Stine's/Lee Correy's novel "Star Driver"........

I want it to work for my personal "reactionless" flying machine --- like a jet-pack, but without the backblast. Safe for landing in public places without scorching bystanders.

I work with vacuum chambers down to 10^-10 atm, so if anyone has a microwave vacuum thruster you want to throw in...


Seriously though, it takes weeks of prep to do space hardware tests, the idea that they would use a vacuum chamber solely to reduce the chance of breeze is idiotic. Their drive produces a pressure differential that will create exactly that effect, in addition to their lack of knowledge in their test equipment.

ThirstyBarbarian said:

They should launch one into orbit and see if it can maneuver. That would pretty much prove it.

Click to expand...

No, that would only demonstrate that it can produce thrust. We already know that rocket motors can do that in a vacuum. What's radical about this claim is that the system allegedly produces movement without anything leaving the device. To demonstrate that, they would need to show that any thrust produced is not, for example, due to heat or some other electromagnetic effect.

-- Roger

The claim they observed 55 uN with a 2.6 watt power input may not be unreasonable because that's what pulsed plasma thrusters will generate, and most other electric thrusters are actually much more efficient. What's ridiculous is the projection of improvements up 0.4 N/KW to 4 N/KW. 0.4 N/KW is 100% efficiency at Isp=500 s and 0.2 N/KW is 100% efficiency at Isp=1000 s. On the surface, these projections are ridiculous unless I'm totally considering the wrong physics.

The 3 laws of thermodynamics in common terms state: 1.) You can't get something for nothing; 2.) You can't break even; and 3.) Doing anything costs something. Have I missed something?

Bob

jadebox said:

No, that would only demonstrate that it can produce thrust. We already know that rocket motors can do that in a vacuum. What's radical about this claim is that the system allegedly produces movement without anything leaving the device. To demonstrate that, they would need to show that any thrust produced is not, for example, due to heat or some other electromagnetic effect.

-- Roger

Click to expand...

I took the "revolutionary" part to be not so much that nothing comes out of the device, but that there was nothing in it to come out in the first place. It's true that nothing would leave the device, but the point of the device is that it doesn't have to contain any reaction mass in order to maneuver in space. If it is built without any reaction mass, launched into space, and can maneuver, then it works, and you don't have questions about whether it is actually pushing against the air in the lab or against the test chamber itself.

(BTW, I wasn't really suggesting this as a serious way to test it. I'm sure that there must be cheaper ways to test in a lab on earth.)

ThirstyBarbarian said:

I took the "revolutionary" part to be not so much that nothing comes out of the device, but that there was nothing in it to come out in the first place.

Click to expand...

Yes, but, if the device moves just because it's emitting heat or another form of electromagnetic radiation, then it is not operating the way the proponents have described it and it's not anything revolutionary.

-- Roger