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Final NASA Eagleworks Paper Confirms Promising EM Drive Results (hacked.com)
An anonymous reader quotes a report from Hacked: Earlier this month Hacked reported that a draft version of the much expected EmDrive paper by the NASA Eagleworks team, had been leaked. Now, the final version of the paper has been published. The NASA Eagleworks paper, titled "Measurement of Impulsive Thrust from a Closed Radio-Frequency Cavity in Vacuum," has been published online as an open access "article in advance" in the American Institute of Aeronautics and Astronautics (AIAA)'s Journal of Propulsion and Power, a prestigious peer-reviewed journal. The paper will appear in the December print issue of the journal. The final version of the paper is very similar to the leaked draft. In particular, the NASA scientists confirm the promising experimental results: "Thrust data from forward, reverse, and null suggested that the system was consistently performing at 1.2 +/- 0.1 mNkW, which was very close to the average impulsive performance measured in air. A number of error sources were considered and discussed." The scientists add that, though the test campaign was not focused on optimizing performance and was more an exercise in existence proof, it is still useful to put the observed thrust-to-power figure of 1.2 mN/kW in context. "[For] missions with very large delta-v requirements, having a propellant consumption rate of zero could offset the higher power requirements. The 1.2 mN/kW performance parameter is over two orders of magnitude higher than other forms of 'zero propellant' propulsion, such as light sails, laser propulsion, and photon rockets having thrust-to-power levels in the 3.33--6.67 uN/kW (or 0.0033--0.0067 mN/kW) range."
In other words, a modest thrust without having to carry fuel can be better, especially for long-distance space missions, than a higher thrust at the cost of having to carry bulky and heavy propellant reserves, and the EmDrive performs much better than the other "zero propellant" propulsion systems studied to date.
It's Steorn all over again.
Apart from the open process and independently verified results
What's the usual format of an EM drive?
Large arrays of them go on the back of our Terran Battleship to propel them out into the darkness as they bring the Light of Mankind to a savage and ignorant galaxy. Until we find someone smarter than us.
The most implication of experimentally confirming these observations would be for our fundamental physical models. Nobody can really say what it means, but it is potentially as important as the discovery of spectral lines, which was instrumental for the development of quantum theory.
As with most discoveries in fundamental physics, the actual applications are often unpredictable and rarely match the initial expectations. If anyone tells you they know, they are talking out of their asses.
They say that they have looked at outgassing, and assumed that its not relevant due to slow temp rise not producing rising force. But that does not cover possibility that the electromagnetic resonances are somehow vaporising and ejecting structure at much higher speeds. At .0012N thrust with 1kW input (and 100% efficiency) a rocket would need exhaust velocity of 1.6e6 m/s and consume around 0.8ng per second - damned difficult to weight with required sensitivity and hard to spot except by looking for evidence in the gases within the chamber as metals will condense out quickly.
Are you serious? If the EM drive works we are at the gates of a major revolution in Physics (as in 'our understanding of Physics'). First we should have to understand how it works, tinker with it till the smallest-lightest-efficientest designs emerge. In parallel, other people would be trying to determine WHY it works. That's a much bigger task, that requires a rewriting of most Physic's textbooks. When we have a new theory that explains the EM drive, then probably still better drives can be designed, perhaps using other kinds of radiation.
What I'm driving at, is that discussing how possibly adequate or inadequate this EM drive is to space travel is like discussing the usefulness of electricity when good old Thales started rubbing amber pieces against animal skins.
Rome taught me patience and assiduous application to detail. Virtues which temper the boldness of great, general views.
... are more or less the same ones than before (= very unclear setup, situation very unlikely to represent the claimed break of the conservation laws, highly restricted conditions not telling much, etc.).
Summary of my impressions after quickly reading this paper:
- The actual methodology generating the thrust isn't clearly explained, 95% of this paper is about the testing conditions (measurements, sources of error, assumptions, etc.). Although I assume that detailed explanations on this front might drive to a level of clarity similar to the one of the tests, as explained in the next point.
- Complex testing setup which is very difficult to be adequately understood from outside. It seems that only people with actual experience under these specific conditions (and, ideally, with physical access to an equivalent setup) are in a position to critically analyse these tests and be specific about the (very likely IMO) source(s) of error.
- Even by ignoring the two aforementioned points, plainly believing that everything is fine and just analysing the results, there are various issues which are somehow against the reliability of this experiment and related out-of-proportion assumptions. Examples in fig. 9: a maximum displacement below 0.005 micrometres (extrapolating such a top performance to interstellar travels is sensible?!); assuming that the error in the measurements remain constant under different conditions (?!); testing just 3 different scenarios (40, 60, 80 W) and getting counter-intuitive results (30/40 = 0.75; 106/60 = 1.76; 76/80 = 0.95; 60 W delivering the best performance?!).
Fig. 19 is even more descriptive by showing a tremendous variability of the measurements; in the best-performing 60 W scenario, they vary from 130 to 45 micronewtons!! With only a few cases being similar enough (85 and 92); out of all the about 20 cases, there are only a few which are identical under the given conditions.
Custom Solvers 2.0 = Alvaro Carballo Garcia = varocarbas.
IAATP working on quantum electrodynamics (QED) and other theories.
The fundamental problem with this experiment is that it appears to violate conservation of momentum. This violation is not something that can be discarded easily: it has been confirmed directly and indirectly in millions of experiments over decades.
Momentum conservation is also a cornerstone of quantum field theory (QFT) and it is a symmetry which survives quantization. The entire Standard Model (SM) is a momentum-conserving QFT. The SM has been confirmed to a high accuracy in particle accelerators for many years. Any violation of momentum conservation would have been quickly noticed. You cannot simply invoke 'quantum mechanics', 'zero point', 'vacuum fluctuations', etc. to explain excess thrust. Momentum conservation is fundamental, both classically and quantum mechanically.
So what about the EM drive results? There is a possibility that some new physics is at play, however it is vastly more likely that there is a systematic error which has not been eliminated. (If I had to guess I would imagine that because a large amount of RF energy is being pumped into large metal cavities, the apparatus is resting at the bottom of a standing wave potential.)
The way to finally confirm or refute this is to take the drive into space. In this case, it is almost certain that the net thrust would be equal to the momentum of the photon flux leaving the drive.
Just because you don't understand how it works doesn't mean it's instantly a "perpetual motion machine". I sincerely doubt it's creating energy from nothing.
Seriously. Top scientists don't know how it works yet. What makes you think you have the answers?
BeauHD. Worst editor since kdawson.
What's the usual format of an EM drive?
NTFS.
Sheesh, evil *and* a jerk. -- Jade
Just imagine this gizmo powered with cold fusion!
Besides your exclusion of relativistic mass increases, you are also assuming that more power isn't required as the drive accelerates. Marketing claims aside, nothing in the static testing so far indicates that, it will only show up when the drive actually continually accelerates something in a test. Acceleration without expelled reaction mass doesn't equal a violation of E=MC^2, it just means the opposite force is coming from something that isn't being expelled by the drive. What it is, is unknown now, but my guess will turn out to be something already predicted by physics.
With F=MA and E=MC^2, no matter what the source of the acceleration force, the accelerated object will start experiencing mass increasing effects and we will have to increase the thrust to maintain the same acceleration, requiring an increase in energy fed into the drive. The EM drive clearly shows a direct correlation between power input and thrust.
If your argument was valid physics, it would apply to all lower power drives including ion thrusters capable of long term acceleration. Hell, the drives on Dawn generate 80 times the thrust force for 10 times the energy of the EM drive. If anything this thing is more inefficient than the NSTAR drives.
Trying to become famous by taking photos. Visit my homepage please.
Just to put the numbers in perspective. A force of 1.2mN/kW is equivalent of a force of 0.12 gram.
A Tesla SP85 has a maximum effect of 350KW. This would (in theory) produce a force of roughly 40 grams, the weight of 10 sugar cubes.
A Nuclear submarine is able to produce an effect of 100MW, giving a theoretical force of 10kg.
A medium nuclear power plant is producing roughly 1000MW, and a force of 100kg.
Now, does it work? No idea, frankly. I'm more inclined to believe the results of, you know, an actual test than someone who didn't do the test but insists it can't work in spite of the test....
It's difficult to convey to a non-physicist just how accurately and consistently quantum field theory describes nature. Physicists routinely make calculations which have lower uncertainly than the best experiments. For example the anomalous magnetic moment (https://en.wikipedia.org/wiki/Anomalous_magnetic_dipole_moment) is in agreement with theory to ten significant figures.
Physicists tend to be fairly cautious describing results, but when it comes to basic theory at energies up to a few hundred GeV we are confident that we have *all* physical effects well and truly nailed. This doesn't mean that we can always solve the equations perfectly: quantum mechanics is hard, but the equations themselves are almost beyond reproach.
It's not undeserved hubris: it's trillions of independent experiments, billions of dollars and hundreds of thousands of man-years working on the theory by lots of very smart people. The theory, quantum field theory (QFT), is simple, consistent and universal. It describes everything we can see around us, with the exception of gravity.
If you ask an actual physicist what he or she thinks of the EM drive, they will overwhelmingly say that is is highly likely there is an unresolved source of error because violation of moment conservation has never been observed and is inconsistent with QFT.
It's very simple, instead of being inefficient like a regular rocket engine and moves the rocket in space, it simply allows the rocket to be stationary and it moves the universe.
Do not look at laser with remaining good eye.
Instead of engineers they need to get some scientists involved because the paper shows a total focus on simply measuring the thrust and zero scientific investigation to investigate the cause of the thrust.
Yeah I know. What an absurd thing to do in a paper titled: "Measurement of Impulsive Thrust from a Closed Radio-Frequency Cavity in Vacuum"
Have you ever considered that there may be other teams doing research on this an this just happens to be the first paper out? Damn them for not doing everything at once and reaching all conclusion at the same time.
While the OP did indeed ask for practical propulsion applications, the implications of a change in physics theory is enormous, as his example illustrates quite well.
Spectral lines led to the realization that energy is not continuous, but discrete in very small units which can interact with matter, and by inverting that principle, small changes to matter can result in large changes to energy. That directly led to the theory behind semiconductors, enabling transistors and other solid-state electronics, ultimately leading to the entirety of modern electronics technology.
Similarly, verifying a repeatable violation of the laws of physics means that those laws are inaccurate. By refining the theory to fit the new observations, we can also revisit our assumptions about what is possible using electromechanics. To address OP's question, energy, not fuel, becomes the limiting factor in propulsion. That in turn alters the theory of rocketry, which affects the limits of human expansion, providing new areas of study for anthropology and sociology.
However, the scope of affect also lies beyond rocketry. If EM can produce thrust, we may be able to miniaturize the device to a nanotechnology scale, as a new tool for nanomachines. As one example off the top of my head, we may be able to produce self-controlled materials that change shape by rearranging microscopic structures, similar to how animal muscles work by moving actin and myosin molecules.
In short, the actual application of any discovery is the increase in understanding of how the universe works, and from that we can derive advances in technologies.
You do not have a moral or legal right to do absolutely anything you want.
False.
Trinity, the very first man-made nuclear explosion, used Plutonium from the Hanford Engineering Works, created in the B, D, and F reactors. You do know that Plutonium doesn't exist in nature, right? It's either created in a reactor via neutron bombardment of U238, or in a cyclotron.
More than that, the Chicago Pile was the first man-made self-sustaining nuclear reaction (in 1941), and the basis of all reactor design that followed to support the Manhattan Project, which made bombs detonated in 1945.
Reactors very much came before the bombs.
Slashdot still doesnâ(TM)t support Unicode after it was added to the HTML standard in 1997.
Your entire post is nonsense. You're "not even wrong".
Socialism: a lie told by totalitarians and believed by fools.