The SpaceDrive Project – First Results on EMDrive and Mach-Effect Thrusters
researchgate.net
researchgate.net
There seemed to be a measurable effect going on, so they tested it.
A big ask for a group of people who's best technical achievement so far is to fly a plane into a building.
I've heard this sentiment a lot when it comes to the EMDrive, but honestly I think it really misunderstands how science progresses in general. For EMDrive to be real, virtually everything we know to be true about physics would have to be false: if you're saying conservation of momentum can be violated, or conservation of energy can be violated, then basically all of modern physics would have to be wrong.
When science, and especially physics, advances, it is very rarely, if ever since Newton's time, that the settled physics is 100% wrong. Instead, the "old" physics tends to be an approximation under most conditions, or there is a new phenomenon that can be explained without really violating the old rules. For example, conservation of momentum still holds under special relativity, it's just that we discovered things without mass can have momentum.
Thus, the only explanation that would really be plausible is if there is "something else" going on with the EMDrive where momentum and energy are still conserved, just that there is something happening beyond our current understanding of "energy" or "momentum". I haven't seen any explanations that even try to postulate what that could be. All I ever have seen is "but the old physics could be wrong!" without an explanation of how it could be wrong.
Besides, virtual particles have to go away at the end of every diagram... They can act as conduits between other particle fields but if a new particle remains after the interaction it will be just another reaction product (nothing virtual or spooky). Some go so far as to say that virtual particles don't particularly exist, but that's a philosophical statement I guess (they do indeed lack many properties of other things that exist). However I can't say much about that as the arguments for this-or-that nonintuitive ontology usually emerge from advanced theoretical research that is beyond my knowledge. (I.e. in momentum space virtual particles don't even remotely seem to exist, but maybe the picture seems more reasonable when you write it all down some other way.)
They also conserve both energy and momentum.
It's almost the opposite of that: a simplification for professionals' sake. You can set up an eternal black hole and enjoy the simplifications its time-invariance permits, but then you have to match the outgoing Hawking radiation flux (as seen at infinity) with an ingoing one.
With a collapsing-matter black hole you lose time-invariance, because, coarsely, there is a region of spacetime where there is spread out matter and no trapping surface ("event horizon", or whatever, let's be agnostic about that), there is a region of spacetime where there is a trapping surface, and finally there is a region of spacetime where the trapping surface is gone and there is a gas of thermal radiation. But on the bright side, then you don't need any ingoing flux to balance the outgoing Hawking radiation. Instead you look at non-trivial Bogoliubov transformations between these different regions, which model how observer in region-with-horizon sees particles that observer in region-with-uncollapsed-matter ("no horizon yet") does not. (You can additionally change the speed of collapse, which changes the difference in particles that the later observer sees: sufficiently slow collapse means no Hawking radiation at all.)
(Professionals even make other simplifications, like dealing with a free-as-in-linear scalar quantum field rather than realistic interacting matter; it won't matter much since "real" Hawking radiation would be almost only photons anyway, and the stark problems around the border between the region with the horizon (and Hawking radiation outside it) and the region with only Hawking radiation (and no horizon) likely do not depend on the precise content of the hottest Hawking radiation.)
This is probably stupid to anybody that knows about physics, but I had to ask :)
And the characteristic of dark matter is that it interacts very weakly or not at all to electromagnetism. It would be very odd if it interacted so strongly with the EM drive that the EM drive could generate noticable thrust from such a diffuse medium.
Finally, dark matter, if it has inertia, should have an inertial frame of reference. That frame is unlikely to be "at rest relative to the surface of the Earth." Therefore, if the EM drive is pushing off dark matter, we'd probably expect it to work more strongly in some directions than others. Think of it as a sail in a ghostly wind.
According to the paper, the EM drive did actually quit working when rotated. However the dark matter wind seems less likely of an explanation than the Earth's magnetic field. ;)
The Earth is changing orientation in the galaxy as it spins, around itself and the Sun. Unless it was done exactly once, this experiment was performed at many orientations relative to the galaxy.
Knowledge of the mechanisms behind X doesn't always precede discovery of X (why would anyone think it would always do so?) Lack of a known mechanism was why John Newlands version of the periodic table was greeted with contempt, and Mendeleev didn't find it easy sledding at first, either. But the contempt was unjustified. Birds were able to fly before the airfoil was discovered or airflow understood. Electricity was a broad field of study (Maxwell's equations, etc) long before the electron was discovered. The how usually trails the what in the history of science.
I won't be shocked if the Emdrive is a wrong turn, but the idea we could know that in advance is sciencism - the satanic inversion of science - not empirical science.
More seriously, there was a good reason to strongly suspect that the EM drive wouldn't overturn physics: we have probed electromagnetic interactions at energy densities far higher (gamma ray scattering) and far lower (radio telescopes) and everything in-between, and they all seem to be points on a continuous surface defined by Maxwell's equations applied to quantum mechanics. A working EM drive would actually be very close to the magic rune I described above: a wildly noncontinuous point where the laws of physics became massively different for one particular arrangement of matter, and then go right back to normal if you step in any direction around it.
(reply to below comment) While not all experiments are equal, there's no right answer, and plenty of room for good and bad luck. The marketplace of ideas ensures enough variety that we don't miss toooo much (maybe.) Yet very often, it's those with the most eccentric and false ideas, such as Keplar, who stumble onto the right path because at least they're looking where nobody else is, for correlations no-one else thought to! So my bias is toward the most novel experiments that are still extremely likely to fail, as I think you agree.
Just this week I was reading up on the Stern-Gerlach Magnet experiment, which discovered spin; something the experimenters absolutely weren't looking for. The idiots (or recipients of blind luck) win a lot of rounds in science, 'cause they're at least trying something genuinely new.
Slightly different alloy = slightly different string theory?
So, there's a point about philosophy of science to be made here. If you test one bronze alloy for antigravity, and then test a slightly different bronze alloy for antigravity, and so on, finding all of them to fall when dropped, how can you know when it's reasonable to stop testing bronze alloys for antigravity? Presumably, you should eventually say "this idea has already been tested," and then stop. However there will always be a new ratio of metals to try: the only way to say "this has been tested" or "this hasn't" is to establish enough of a theory to make predictions about the effect of gravity on every bronze alloy, and then trust it when it says it will not become negative (at least, trust it enough to let it rule out potential experiments from grant approval.) When we say, "a new arrangement of photons will still conserve momentum," we are performing exactly the kind of interpolation from other experiments involving photons in cavities that, previously, stopped us from making more and more bronze bars in the search for antigravity.
1. "actual" isn't that actual if enough independent
scientists aren't duplicating it using scientifically
accepted testing procedures.
2. "actual" isn't that actual when the quantity is down
at around noise level.
You're using words like "almost seems" that just don't match up to the results seen, especially considering the flawed testing methods used.
The EMDrive breaks the known laws of physics as much as any potential perpetual motion machine would, so for it to be correct would imply as much is wrong as our knowledge of physics as the existence of a perpetual motion machine would.
"any device with a thrust-to-power ratio greater than the photon rocket would be able to operate as a perpetual motion machine" https://arxiv.org/abs/1506.00494
Which raises the specualtive question of whether the Emdrive exploits the Casimir effect to obtain a tiny thrust (in which case a drive subdivided into a vast number of really small trapesoidal sections might produce much more thrust.
Any such effect that exists, would not be called the "Casimir effect" because it would have to obey completely different laws than the actual observed Casimir effect seems to. The Casimir effect is actually evidence against such an effect, insofar as it's perfectly explainable in terms of conservative forces.
I'm unsure about why you think that laws of conservation will not hold for Ether, AKA Quantum Field, AKA physical vacuum. If we will be able to get energy from QF, QF will lost that energy and will cool down, so Casimir effect will be smaller until it will vanish. However, there is no shortage of PV in space, and Sun is pretty good at heating it.
However, because of wave-particle duality, and because waves are propagating without moving, and because waves are propagating at speed of light, Casimir effect may be unaffected by rotation even when exposed to raw vacuum for speed less than 50% of speed of light.
Exploiting the Casimir effect can't give free momentum, because the derivation of the force is rooted in quantum field theory, which like any other physical theory of the last 400 years contains conservation of momentum at its very core.
Thank you. That led me to learning about:
https://en.m.wikipedia.org/wiki/Alcubierre_drive
And:
So, supposedly, if em drive worked, you could produce a flying car that could hover without new energy input (it was supposed to use superconducting materials in the cavity). As soon as you started mooving the energy in the cavity started to decrease - so you would be transfering the energy/momentum of photons in the cavity to your ship?
Anyway, my physics gut told me this was all bullshit, but I wanted to believe sooo much, if this worked, it would have been the greatest invention in human history.
"applying a constant force results in a constant acceleration, the kinetic energy of a mass driven by such a device increases quadratically with time, while the energy input increases only linearly with time. Thus, at some point, the kinetic energy of the device-driven mass exceeds the energy input, and if this energy is collected via decelerating the mass (via regenerative electromagnetic braking, for example), then there would be a net gain in energy."
Conservation is not a fundamental law, but an emergent property of a deeper principle called Noether's Theorem:
https://en.wikipedia.org/wiki/Noether%27s_theorem
https://www.youtube.com/watch?v=04ERSb06dOg&t=594s
And it is constantly violated.
The metric expansion only operates on scales much larger than that of the solar system (and even larger than that of the Milky Way and its collection of nearby neighbours).
(One can take a theory other than General Relativity and finely-tune the expansion of the solar system to match the null results on measures of it, and this is done in some quintessence and other models, but this won't help one do away with exact conservation of energy at scales of EmDrives; or give much room to have more energy moving into (or out of) a boundary drawn outside the solar system and the wider universe).
If one or another of these so-called fundamental laws is being apparently broken by the EmDrive then that would make it a very very unusual object. Consequently there would need to be repeatable verifiable evidence that it does so and at least the beginnings of a theory as to how in fact this breakage is occurring–Noether's theorem notwithstanding.
Right, and we have determined the exact local symmetry with which we can use Noether's Theorem to show a set of exact conservation laws, and expect it to apply everywhere in the universe (and we test against that assiduously).
Concretely, we have ample direct experimental evidence that everywhere accessible in the solar system, to extremely high precision, at length scales of microseconds (and light-microseconds), spacetime has an exact local symmetry group SO(1,3), which is the Poincaré group. The exact symmetries of the Poincaré group include invariance of systems under rotations and translations. Colloquially, it doesn't matter whether your laboratory is laid out east-west vs north-south if you're testing Poincaré invariance wholly within the laboratory, i.e., you're not deliberately testing something much larger, like the Earth's magnetic field, or solar neutrinos, and it doesn't matter if you run your tests in northern hemisphere spring or northern hemisphere winter (notably the planet is at a very different point compared to other solar system bodies at both times, so this is a full spacetime translation).
That is, the results of locally-determinable non-gravitational experiments do not depend on position in spacetime, or orientation with respect to some distant object.
The rotational invariance, via Noether, gives us conservation of angular momentum.
The translation invariance, via Noether, gives us conservation of energy-monentum. With any reasonable splitting of 4-spacetime into three spatial and one timelike dimension, we take the resulting spatial translation invariance and get conservation of linear momentum, and the resulting time translation invariance and get conservation of energy.
In General Relativity, we are guaranteed a patch of flat spacetime around every point in the manifold. Far from massive objects, that patch can cover a fairly large region of spacetime (>> microseconds or light-microseconds). The metric of flat spacetime directly maps to the Poincaré group; more formally, the Poincaré group is the local group theory of Minkowski space, and the Lorentzian metric on the whole spacetime guarantees Minkowski space in small regions.
So even though we must bring in the equivalence principle when doing so, we fully preserve Poincaré invariance at laboratory scales even when on the surface of the various massive bodies in our solar system. This has already been tested experimentally to high precision against several different planetary objects other than the Earth, and several objects which aren't in approximate hydrostatic equilibrium (and thus not planets).
Everywhere we observe (on Earth, elsewhere in the solar system, and with astronomical observations) we see evidence for local Poincaré invariance (up to strong gravity, which is hidden behind event horizons anyway) from emissions and absorptions spectra, and various other observables.
Note, though, that while everywhere-flat spacetime -- the setting of Special Relativity, and in fact what makes the theory Special -- has global Poincaré symmetry, that is not true for spacetime which is not everywhere flat. The global symmetries of the FLRW model of the standard cosmology, for instance, are not time-translation invariant. Therefore there is no correspondence via Noether to a conservation of energy. However, the "swiss-cheese" approach lets us replace a comoving speck of the standard cosmology's expanding dust with a smaller-than-Megaparsec scale region of flat spacetime (corresponding to a region of spacetime far outside any galaxy clusters) or a smaller-than-Megaparsec scale region of Schwarzschild(-like) spacetime (corresponding to a region of spacetime in which there is some collapsing mass, like a galaxy cluster). This is a "sewing" or "stitching-in" process which is described in various places like Misner-Thorne-Wheeler's section on the Israel junction conditions. The standard cosmology gives us a slicing into spatial and timelike dimensions. Thus within in the two examples of "stitched-in" regions, we would the local symmetries in each such spacetime to apply, with appropriately conserved quantities per Noether's Theorem.
Indeed, we test to see whether building up the solar system by sewing together small patches of Schwarzschild(-like) and Minkowski spacetimes accords with the previously mentioned observational tests of General Relativity, at the level of numerical relativity. They do.
So, there is no escaping conservation-of-energy within the solar system theoretically. Tests of the fundamental pieces of this (which are ultimately tests of the equivalence principle under some very light assumptions, and tests of the Standard Model of Particle Physics, which incorporates the Poincaré group directly into it's formalism) support this to many decimal places.
Thus,
> it is constantly violated
is not true anywhere within the solar system, nor anywhere within the local group of galaxies back to when it first started forming stars. That is a rather large volume of spacetime.
However, after one moves sufficiently far away from that region, spacetime is no longer well modelled by a Schwarzschild-like solution, but is instead well-modelled by a Robertson-Walker metric (conversely, within the Milky way, nowhere is space well-modelled by a Robertson-Walker metric). In faraway regions of the universe which matches the observables of Robertson-Walker, one should expect a failure of the global symmetries of Schwarzschild(-like) spacetime.
Finally, even with an expanding Friedmann-Lemaître-Robertson-Walker (FLRW) model, and without "swiss cheese-ing" it, there is still at every point a small patch of spacetime in which the local symmetries are experimentally indistinguishable from Poincaré. Thus, to observe a violation of conservation of momentum (or energy) in our standard expanding spacetime with the observed value for the cosmological constant, you need a separation of millions of lightyears. This is why we see a cosmological redshift from distant galaxies but no cosmological redshift from nearby ones.
So I think being skeptical of accepted physics in any specific way isn't something a layman has much business doing. Of course there will be things we think we know that turn out to be wrong, but a layman can see such things everywhere, not just the places they will actually appear.
And to be clear, I’m not being skeptical of accepted physics. When radio was discovered it didn’t change the accepted body of knowledge so much as it added new things we could do.
https://news.ycombinator.com/item?id=17098795
https://news.ycombinator.com/item?id=17098873
We would expect new discoveries to be outside the range of what we've already tested, not randomly in the middle of it. For example, special relativity becomes significant at high speeds that nobody had ever studied before, not at some odd speed between a horse and a train.
But if you didn't know what has already been tested, you wouldn't know where "outside" is. The fact that the original device used a magnetron from a microwave oven suggests it was well within what we've already studied. Maybe the novel aspect is the very tiny effect which nobody measured accurately enough to notice before.
Strictly speaking, all we know boils down to probabilistic statements. So yes, in some absolute sense, we might discover we're all totally wrong about something really fundamental. But we also know the bound on that probability is very, very, very, very, low.
https://en.wikipedia.org/wiki/RF_resonant_cavity_thruster
"Vacuum energy
Main articles: Zero-point energy, Quantum vacuum thruster, and Pilot wave Harold White, the lead scientist in the NASA investigations, suggested in 2014 that their model could be an example of a quantum vacuum thruster (QVT). This is a theoretical system that would use magnetohydrodynamics to generate thrust, similar to conventional plasma thrusters, only using the fleeting vacuum quantum fluctuations of the zero-point field as an extremely low-density plasma.[82][23][83][84]
White's 2016 paper states that pilot-wave theories, non-mainstream interpretations of quantum mechanics based on the de Broglie–Bohm theory, may help explain how QVTs could "push off of the quantum vacuum and preserve the laws of conservation of energy and conservation of momentum.".
In 2017, a Portuguese team published a paper proposing pilot-wave theory as a possible explanation to the EmDrive thrust, that would not break conservation laws. The principle is that a sufficiently strong asymmetrical electromagnetic field could act as a pilot wave. The cavity would then be attracted toward regions of higher electromagnetic intensity. The researchers propose to increase thrust by shaping the cavity with an exponential form like that of a trumpet bell instead of a frustum.[85][86]"
Skepticism about the EmDrive from Physicists has been nearly universal. There's always a few contrarians and heretics, but the consensus is what it is for good reason: it's best supported by the evidence.
This is not about "laymen" lacking comprehension, and the condescension doesn't help your case.
So what?
Skepticism and status quo consensus does not push any field forward into new territory. The vast majority of physicist I would argue are simply refiners of areas pioneered by a scant few others, or working in the industry (myself included). Like it or not, these refiner types aren't the ones earning Nobels. You see this in almost all fields. Current AI advancement originated with maybe 3 researchers pioneer theories, its didn't spontaneously manifest from the consensus Computer Science crowd. Its the open minded mavericks on the outskirts types looking for a way to walk the line or even circumvent current understanding that stumble upon possible breakthrough science where others can move in and refine.
Sorry, but it really bugs me when I see relatively smart (but still not Physicist) techy types (relative physics laymen in my mind) defaulting to "it cant be therefor it isn't" logic. This is the Argument from Ignorance logical fallacy. Have they even bothered to read the alternative explanations that might explain the experimental result? You can read a few in my wiki link above. If not then what the F do they know then! Sure it could be just measurement error, or it could be the biggest breakthrough in space travel we've seen and may lend credence to an obscure theory such as pilot waves and quantum vacuum flux. Better not look under that rock through because it might upset the consensus who says there's nothing there. /s People don't realize how closed minded that sort of mindset really is. Armchair know-nothings looking for anything to shoot down and pat themselves on the back for deserve condescension.
A lot of these things are often scams, but in this case i think everyone involved was genuine and believed they had found something great.
Well, assuming one can violate only one law of physics at a time, this is just semantics.
Reactionless drives just produce force, pushing off "nothing." They violate conservation of momentum and break physics as we know it pretty conclusively.
Flight would have been considered reactionless thrust before it was understood that air had substance.
Last time I looked it, this EM Drive research was not NASA project. They just gave a NASA engineer a warehouse to pursue his ideas on his own time like good research organization does.
The "Eagleworks Laboratories" or "Advanced Propulsion Physics Laboratory" is just what Harold G. White calls the warehouse. It has no website or staff from NASA.
"Theoretically" 95% of the universe is made of invisible, unexplained stuff...
Dark matter doesn't interact with either electrons or photons, and neither does dark energy. So they're irrelevant; they can't be used to explain the behavior of the EMDrive, because the EMDrive is made of matter.
It was falsified by the aberrant rotation curves way back in the 1930s, the "dark matter" save was allowed for awhile but still no other evidence has been found for that. The only evidence is that GR predicts the wrong thing. It doesn't matter how many successes your theory has when we are talking about taking it as fact, only whether there is a single fail.
Regarding your individual examples:
>"Mercury's apsidal precession computed precisely"
- GR was designed to fit this, which is great.. but doesn't count as a confirmation.
>"time delation by gravity measured by placing atomic clocks on mountaintops and airplanes"
- Looks like they had to modify the original predictions to fit the data, ie Einstein didn't anticipate accounting for the rotation of the earth: http://www.conspiracyoflight.com/Hafele/HafeleKeating.html
So, like the case of mercury's precession it is more a post-diction.
> "observed gravitational waves"
- There still hasn't been one independently verified, they need to detect a GW, calculate the coordinates, then tell other people where to find a GRB, kilonova, etc. So far this has not happened.
>"gravitational lensing"
- This idea predates GR: https://arxiv.org/abs/1206.1165. Also, don't the quantitative predictions here rely on the dark matter fudge factor?
How can you claim this? GR is derived from first principles only. It also does not need any new physical constant to describe Mercury's apsidal precession. There are no adjustable parameters. It fits precisely even without the cosmological constant which you seem to hate with a passion.
>- This idea predates GR: https://arxiv.org/abs/1206.1165
What?! How can you possibly claim that work published in the 1930s predates GR, which was published in 1915 (Hilbert) and 1916 (Einstein himself). An incomplete version of the theory was published by Einstein in 1912.
You can derive many theories from first principles but they need to be checked against observation to be useful physics... explaining the orbit of mercury was one of the main checks of any theory. All theories that could not explain that better than Newton were filtered out. My point is only this does not count as a prediction, which needs to be on new data.
>"What?! How can you possibly claim that work published in the 1930s predates GR"
This is something you've made up? The source I provided quotes Henry Cavendish on this from ~1800:
"To find the bending of a ray of light which passes near the surface of any body by the attraction of that body"
You can achieve what looks like reactionless thrust by swimming in spacetime, according to GR:
http://science.sciencemag.org/content/299/5614/1865.full
So I think your statement is only true in the strictest sense using the words literally, but the spirit of the claim is actually false: theory actually predicts the existence of reactionless motion.
No negative mass, translations can occur purely by mechanical deformations in a curved spacetime.
Our results show that the magnetic interaction from not sufficiently shielded cables or thrusters are a major factor that needs to be taken into account for proper µN thrust measurements for these type of devices.
Reading the paper one can finally get to what we want to know, "Do these thrusters work?" The answer is no and/or can't tell yet.
Under the EMDrive section:
This clearly indicates that the “thrust” is not coming from the EMDrive but from some electromagnetic interaction.
Under the Mach-Effect section:
This again indicates that there must be some electromagnetic interaction or thermally induced center of mass shift that is masking any real thrust value.
Edit - I did not read the whole paper but skimmed for these descriptions of if they found any real thrust signal.
(Edit footnote: only seen s1/2, anything surprising in s3 is unknown to me).
Iirc, there's some mention of pre-Epstein fusion ships that needed even more water.
The alien forces demonstrably have a reactionless capability though (see: Eros) that utterly outmatches the Epstein drive.
Everyone that hopes for a bright future would absolutely love a reactionless drive. I'd love it. But it's not real. We've seen lots of very bad methodology and things like researchers ignoring the fact that a null setup still produces the same thrust even though the drive has been modified not to work. With forces of this tiny order of magnitude it's incredibly hard to get accurate readings, and readings within the margin of error of the instrumentation should not be reported to sensationalist media as promising.
This is just another one of those ufo antigravity quacks you see on youtube, but somehow they got their day in court. I can't explain how much I'd love to be proven wrong, but reactionless drives are physically ludicrous in every single way we understand the universe. Is it possible for us to be wrong? Sure. Is it possible that we're wrong about literally every observation we've ever made in the history of physics? I very much doubt it and it's going to take more than a badly set-up experiment featuring a microwave stuffed into a tuba to convince anyone of that.
So my wishes aside, I feel like this is very tenuous, and is going to come down to "better measurement isolated an effect causing this" more then "there is now a tractable reactionless drive at scale for big things"
First, someone proposed a design that violates both conservation of momentum and conservation of energy, but that's cool because you know, fuck physics. Then there was a hoax and yellow journalism and in the end, several experiments failed to confirm/reproduce the effect, but that's cool because we have this awesome theory we are trying to confirm, right?
By the way, I am looking for a team of physicists that will confirm my revolutionary Tooth Fairy Drive(tm).
The thrust, if any, is so weak it's down in the noise. For a propulsion system, that's a big problem. It's like cold fusion in that way.
I feel like, if this is real, it's one of those sci-fi MacGuffin technologies. Literally changes everything.
For the piezo one the predicted thrust was below the noise threshold in their final tests (specifically below center of mass movements that were also - to my reading - due to the control electronics)
In the interim the air force has sent up the classified X-37 [1]. They've stated it's mission purpose is "risk reduction, experimentation, and operational concept development for reusable space vehicle technologies, in support of long-term developmental space objectives". That's certainly a horoscope style description, but at the same time it does seem to fit quite well for live testing of propellantless drives, even if not as a primary mission.
Furthermore, if the EM-drive did work, it would have a beyond revolutionary impact on everything and so it would not be surprising that it would end up getting classified after passing the initial slew of tests thrown at it.
Sigh, will wait for the next "deformator of space/time curvature" device for the human race to reach stars ...
Apologies for formatting, but the title doesn’t match the conclusion of the paper.
“First measurement campaigns were carried out with both thruster models reaching thrust/thrust-to- power levels comparable to claimed values. However, we found that e.g. magnetic interaction from twisted-pair cables and amplifiers with the Earth’s magnetic field can be a significant error source for EMDrives.”
There was no experimental validation of this, just speculation based on their observations. They propose a simple fix, run the experiment in a magnetically shielded environment. They suggest Mu metal for maximum shielding, which would be good, but I’m a little skeptical that the vacuum vessels used in previous tests would have allowed a substantial flux of earths magnetic field through the environment. Using my phone's basic magnetometer, I get an order of magnitude reduction in field strength by placing it ~8" inside my oven and leaving the door open.
In any event they are probably on to something here. Certainly a more plausible explanation than any of the alternatives.
Nevermind, they are not using a magnetron like the original concept.
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Imagine turning a rocket from horizontal to vertical and finding it still goes up, despite the exhaust from the engine going sideways.
The simple solution being to put it in space, turn it on, and see if it 'stays' in space.
The claimed amount of thrust is significant enough that it will either obviously succeed or fail if you actually put it in space.
That would still be an extremely useful invention.
I was thinking about this more from a practical perspective. And what matters is "does it work", and much less so "how does it work".
I guess if it based on magnetic fields, then it wouldn't be useful for long range space travel but it would still be extremely useful for planet scale space travel!
already invented, already in use, not as great as you'd hope.
https://en.wikipedia.org/wiki/Magnetorquer
> I guess if it based on magnetic fields, then it wouldn't be useful for long range space travel but it would still be extremely useful for planet scale space travel!
turns out it isn't that effective. which can be determined with a sophomore-level understanding of physics and magnetic fields.
0-60 in 1 hour is actually not so bad in space! That’s 10,000mph per week.
And these observable effects are large when you compare them to OTHER forms of space travel.
IE, if you can have a propellant less method of travel in space, of the amount that the EM drive supposedly does, this is a BIG DEAL.
The effect doesn't increase in space. Instead, the "small" effect when compared to earth methods of transportation, are extremely useful in space.
LEO has loads of stuff to interact with, and building a test article that won't drift due to, eg, materials outgassing is a specialist challenge.
The Planetary Society have will be testing their lightsail later this year and it's been years, one launch failure, one engineering demonstrator, and now an actual test bird with its companion (so it has something to measure distances against). And that's for something which has physics on its side and is adored by Sagan-era enginerds.
First demonstrate the thing in a lab. Otherwise nobody will take a launch request seriously, except maybe a non-expert bitcoin billionaire.