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Leaked NASA Paper Suggests The 'Impossible' EM Drive Really Does Work (sciencealert.com)
A source close to NASA Eagleworks has leaked the test results of the 'impossible' EM Drive. While it's important to note that the results that have been leaked haven't been published in an academic journal, they do suggest that the system works and is capable of generating force of 1.2 millinewtons per kilowatt in a vacuum. ScienceAlert reports: The paper concludes that, after error measurements have been accounted for, the EM Drive generates force of 1.2 millinewtons per kilowatt in a vacuum. That's not an insignificant amount -- to put it into perspective, the super-powerful Hall thruster generates force of 60 millinewtons per kilowatt, an order of magnitude more than the EM Drive. But the Hall thruster uses fuel and requires a spacecraft to carry heavy propellants, and that extra weight could offset the higher thrust, the NASA Eagleworks team conclude in the paper. Light sails on the other hand, which are currently the most popular form of zero-propellant propulsion, use beams of sunlight to propel them forward rather than fuel. And they only generate force up to 6.67 micronewtons per kilowatt - two orders of magnitude less than NASA's EM Drive, says the paper. The NASA Eagleworks team measured the EM Drive's force using a low thrust pendulum at the Johnson Space Centre, and the tests were performed at 40, 60, and 80 watts. They were looking for any sign that the thrust could be a result of another anomaly in the system, but for now, that doesn't appear to be the case. "The test campaign included a null thrust test effort to identify any mundane sources of impulsive thrust, however none were identified," the team, led by Harold White, concluded in the paper. "Thrust data from forward, reverse, and null suggests that the system is consistently performing with a thrust to power ratio of 1.2 +/- 0.1 millinewtons per kilowatt." But the team does acknowledge that more research is needed to eliminate the possibility that thermal expansion could be somehow skewing the results. They also make it clear that this testing wasn't designed to optimize the thrust of the EM Drive, but simply to test whether it worked, so further tweaking could make the propulsion system more efficient and powerful.
Because if Trump wins, we need a way to leave this planet...
Mostly random stuff.
The physical laws went out the door months ago.
How can I believe you when you tell me what I don't want to hear?
I need to see more than this article to convince me this works.
They are directly related. https://ntrs.nasa.gov/search.jsp?R=20110023492
Ran some numbers. Assuming the power generator and thruster itself has zero mass (obviously not, but it lets us set an upper limit), the energy available in 1kg of U235, at 1.2 millinewtons/kw, would accelerate that 1 kg mass to about 0.35 C, over the course of about 1000 days.
Add in mass of ship, generators and thrusters and you're looking at considerably less acceleration and top speed, but if this thing works at all (a big IF, granted), manned starships are just within the range of possibility. It'd still be a multi-year (probably multi-decade) trip, but hey.
I thought the science was settled on Newton's laws...
First rule of science: Science doesn't settle
Hanlon's Razor -- Never attribute to malice that which is adequately explained by stupidity.
Eagleworks is NASA's "check weird shit and see if its real" department, so they are exactly the place to check this.
How is this any different from "magical force that synchronizes photons across space and time.... but only if I pre-filter the results of my experiments before shoving them into my statistical test"?
Higher physics is absolutely full of magic pseudo science shit, and this might be something real and simple, that just isn't understood by the current bogus nature of magic fluffy physics.
And if they pump in 1.21 Gigawatts, they're going to see some serious shit!
I thought the science was settled on Newton's laws...
Firstly, Newton's laws are based on observation and assumptions.
The observations gives us formulas that seem to fit, but there's no guarantee that those formulas describe all situations in the universe.
The assumptions, from Noether's theorem stating that symmetries imply conservation laws, are that the universe is smooth, in the mathematical sense of smooth being that space is infinitely divisible. We know that last part isn't true: you cannot measure position to an arbitrary precision in the universe.
It is therefore seen that Newton's laws become increasingly inaccurate when the scale is very large (relativity), or very small (quantum mechanics).
You might check out the Casimir effect some time.
It's not predicted by Newton's laws, but measurable and predictable using QM.
Anyone who says "EM drive cannot work because it violates my understanding of physics" should really check out the Casimir effect.
If your understanding of physics does not predict the Casimir effect, you probably shouldn't be commenting on the EM drive, or results from NASA rocket scientists.
It's not so much newtons laws per se, but energy and momentum conservation laws which are a consequence of very fundamental symmetry laws. See Noether's theorem. That's why physicists have very hard time buying anything that violates these very fundamental principles.
If you use 1 kW to generate photons and use them as your rocket exhaust, then you produce (1 kilowatt / speed of light) = 0.00334 millinewtons. This EM drive produces 360 times more thrust, so it can't be explained that way.
Here's the thing people that don't really understand the physics don't get. Mass is energy energy is mass. If you're throwing photons out the back that you are creating then you are ejecting mass.
While a photon rocket is efficient in terms of mass it's actually terrible in terms of the energy required to accelerate something.
They are directly related. https://ntrs.nasa.gov/search.j...
As the NASA document you cite (HTML FTW!) says, it's "an advanced propulsion physics laboratory, informally known as "Eagleworks"" being implemented by NASA Johnson Space Center (NASA/JSC), so it is part of NASA.
That's not why the EM drive is neat. The force provided by emitted radiation is a fairly well understood and predictable phenomenon. The EM drive has a sealed microwave cavity, so it doesn't emit many photons, and those that it does through thermal radiation are measured and accounted for. Despite that, the EM drive appears to produce an additional force, that is what makes it neat.
Yes photons have momentum and a photon drive would be 1kW / 0.00334 millinewtons.
It's usefulness as a propulsion device remains to be seen.
First, it may ultimately be determined to be the result of experimental errors or failure to account for various effects. Good science, but boring outcome.
Or it may be found to work, and be proven to be exploiting some currently unknown or poorly understood area of physics. Understanding then how it works and how it produces its force will lead to potential useful applications. If it's understood how it works its possible one could be designed to have better thrust than what we've seen. For all we know it may be possible some way to somehow produce 1 newton/watt.
There was an article on slashdot many months ago about a paper that hypothesized how the devices work, and made a variety of predictions on how changing the design of the device should result in difference performance characteristics. Studying effects like that will be important in the science of this device.
I get the no fuel and I get the very little force but I can't imagine the implications for it.
A slow, steady thrust. In the vacuum of space, there's no thrust wasted to keep you at speed, like flying in the atmosphere. Over time, even a tiny thrust can build you up to phenomenal speeds. Just make sure you turn your engine around and start to slow down at the halfway point of your journey.
The only thing worse than a Democrat is a Republican.
I'm no physicist myself, and physicists don't understand this thing anyway, but here's my understanding:
Yes, appears that the only input is electricity, and it seems to produce thrust. So if electricity is free, a tiny amount of thrust is free. I say it APPEARS that the only input is electricity- many reactions which we now understand include oxygen from ambient air as an input, and that might have easily go unnoticed in an experiment before the reaction was understood. Similarly, it's possible that this thruster is using some non-obvious input, such as ambient radiation.
We don't know if one could be built much larger, or what the current capacity is for a given size. Maybe a 100,000 watt one could be small, maybe it would need to be very large. Maybe it would be far more efficient, maybe far less. We're still trying to confirm that the thing works at all.
> would I be right in thinking this thing would incredibly slowly start moving the ship and over a ridiculous amount of time, eventually be moving very rapidly and in theory (?) just keep on accelerating?
Yes, in theory, up to near the speed of light. Or maybe not. 1500 years ago someone discovered that if you burned charcoal mixed with livestock poop in a bamboo shoot, you got a similarly weak thrust. Later we figured out it was the dried pee, not the poop, that mattered and adding sulfur helped. So a thousand years ago they had black powder rockets, which kept accelerating through the air as long as the engine kept burning. Now we know that a rocket won't keep accelerating forever in air, but it took a thousand years to figure that out. We're still in the "poop in a tube" stage of EM drives, so we really don't know what the potential is.
Is this post from 1905?
No, it's from ignorance.
Slashdot, fix the reply notifications... You won't get away with it...
The Eagleworks paper has already been accepted by the AIAA, which could fairly be described as "reputable". It will appear in the December 2016 issue.
Why would anyone engrave "Elbereth"?
I'm at a loss to think of something from technological history that is comparable to this possibility: something that didn't seen possible or feasible under the known laws of physics or nature, but turned out to actually "fly".
The laser perhaps? I don't think it could be conceived of until Einstein.
https://en.wikipedia.org/wiki/...
The difference with this discovery (if true) is that Einstein laid the theoretical framework and then the laser was built 43 years later (36 years for the maser) while in this case we appear to have an empirical device with no solid theory behind it (yet...)
God said, "div D = rho, div B = 0, curl E = -@B/@t, curl H = J + @D/@t," and there was light.
I believe your math is wrong. U235 releases 202.5 MeV per atom undergoing fission, so that means 1 kg can generate 83.14 TJ from fission. Assuming 100% efficiency, a massless drive, and no mass loss from propellants, that means there is enough energy from fission to reach a velocity of 0.043 c relative to the rest frame.
dE = (m - m') c^2 = m' c^2 (gamma - 1) => m' c^2 = m c^2 (1 - dE/(m c^2)) = m c^2 (1 - rho)
rho = dE/(m c^2) = 83.14 TJ / 89.88 PJ = 9.25e-4
rho = (1 - rho) (gamma - 1) => gamma = 1/(1 - rho) = 1/sqrt(1 - beta^2)
(1 - rho)^2 = 1 - beta^2 => beta^2 = rho (2 - rho) = 1.85e-3
beta = sqrt(rho (2 - rho)) = 0.0430
http://www.americanthinker.com...
http://www.killclimatedeniers....
http://www.climatedepot.com/20...
Calling upon the government to execute those with a different point of view is something I'd consider a death threat.
I'm sure we'll find some explanation that requires only a fairly moderate change in our understanding of what constitutes action and reaction.
It's vastly more likely it's experimental error. We're talking about 10mn/kW or so. Most people just don't understand the difference in scales.
Go bust open your microwave, that's got nearly 1000W of microwave generating capacity in it (probably 700-800W). Now find something weighing a milligram. About half a mosquito should do. Now figure out how to get that much power into something that can reliable measure the weight of that half mosquito.
Not easy. Your microwave gets HOT. And thermal expansion is a thing. So are magnetic fields.
SJW n. One who posts facts.
Here in Europe (specifically Germany) we always say a photon has mass because E=mc^2 but its rest mass is 0
No we do not say this in Europe and none of the Germans I have worked with at CERN have ever said this either because it is provably wrong. Photons have momentum but no mass. Either you had a really bad physics teacher or you did not understand what you were being taught. For a photon E=pc where 'p' is the momentum.
No, it really does. Conservation of momentum is a principle very deeply baked into physics and has had a vast amount of testing. It's reached the point where anyone claiming otherwise is quire reasonably considered a crackpot unless they have some quite amazingly compelling evidence.
Second, everyone that does speculate about it agrees that to probe the existence of this discretization would require particle collisions with energy around the Planck energy, about 10^28 eV.
That's a rather strong statement considering that there are groups on ATLAS and CMS looking for evidence of Large Extra Dimensions which would reduce the energy scale for this to a few tens of TeV. Personally I don't think they will find anything but certainly they are clearly speculating about it at far lower energy scales.
To think that some lame tabletop experiment using only classical electrodynamics, running at most at 80 watts, somehow magically found a way to probe phenomena from an energy scale 15 orders of magnitude larger than the LHC scale, just shows a complete lack of knowledge of all the science involved.
Unfortunately again this is not really a correct thing to say because there are such experiments hunting for axion models of Dark Matter. The LHC is one way to get at high energy physics that is almost guaranteed to find new physics in our energy reach so it is worth the huge cost. However this does not rule out others trying lower budget approaches which can afford to be riskier and to only probe certain models. It is worth remembering that only a few years ago the Nobel prize was awarded to a group which essentially used scotch tape to separate graphite layers something which far more expensive approaches had failed to do.
A better and far more plausible explanation for what's happening is here.
And this fellow doesn't just do some hand waving. He has a theory, it is coherent, it is testable and falsifiable, and it also explains the galaxy rotation problem and the flyby anomaly accurately. As well as the EmDrive.
He's worth reading.
Weaselmancer
rediculous.
There is nothing new to be discovered in physics now. All that remains is more and more precise measurement
-- Lord Kelvin, 1900, when people still believed in the luminiferous aether.
What physics revolutions appeared in the early 1900s, do you think?
Vintage computer games and RPG books available. Email me if you're interested.
"I am planning to get out while I can whichever candidate wins. They are all mentally ill, more than a few sociopathic,..."
Sure, but one of them is also yuugely stupid.
Yes, and none of the paper authors are related in any way to Shawyer or Fetta. You know, like in the definition of "independent".
Scientists claim to be all about logic and reason and testing and evidence and then they deny something when it's right in front of their face because it doesn't mesh with what can only be called their particular belief system. Absolute lunacy.
I would think a space drive powered by experimental error would be quite useful, considering what a unlimited resource it could tap.
the preceding comment is my own and in no way reflects the opinion of the Joint Chiefs of Staff