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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?
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.
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.
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.
Here's a link to the NASA paper on the apparently successful test: https://drive.google.com/file/...
And here is a presentation by the technology's inventor, Roger Shawyer https://vimeo.com/channels/Emd...
Warning: Shawyer may well be brilliant, but he is the Anti-Musk in terms of his presenting and motivational skills. This guy could seriously announce a working warp drive in a way that would make people walk out of the presentation half way through. If he has funding problems, he needs to get someone else to present his technology and business case for him.
Where are we going and why are we in a handbasket?
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"?
Warning: Shawyer may well be brilliant,
Nope. He first "derived" it using relativity and then ran with the result. It was obvious to just about every physicist ever that the result MUST have been bogus because relativity probably conserves momentum. The thing is, that's a mathematical proof so it holds always, no matter how clever your shape, how many springs or magnets you have or how smart you seem to be.
It is literally impossible to have a reactionless thruster while constrained by the bounds of relativity. This is well known and thoroughly proven and is basic undergrad level physics, yet was apparently unknown to Shawyer.
Not only that, he wouldn't even accept the result (i.e. Noether's theorem) until someone found the actual error in his working. It wa eventually found.
Not a great start for brilliance.
SJW n. One who posts facts.
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.
Well, if the drive works, then either the symmetry underlying conservation of momentum isn't entriely true (it wouldn't be the first time we discovered a surprising lack of symmetry, you know), or the drive isn't entirely reactionless. I think it is important to always be willing to keep an open mind, when we don't know for certain; what you are saying is "No, impossible, so I am not even going to look". Personally, I think preservation of momentum is true; so in my view there must be an escape of momentum that we haven't figured - if this works. This doesn't strike me as unthinkable - after all, energy is put in, so it must go somewhere. We just need to find an explanation.
Well, if the drive works, then either the symmetry underlying conservation of momentum isn't entriely true (it wouldn't be the first time we discovered a surprising lack of symmetry, you know), or the drive isn't entirely reactionless.
Yes, and that would mean it's a perpetual motion machine too. This would be pretty much the largest result in physics ever. You can see why people, including myself reckon it's completely bogus.
or the drive isn't entirely reactionless
Then it has to be generating reaction momentum from something. The thrust is too high for that.
I think it is important to always be willing to keep an open mind, when we don't know for certain; what you are saying is "No, impossible, so I am not even going to look".
No. You need to be open minded, but not so open minded that your brain falls out. What makes *this* perpetual motion machine different enough from all the others that it's worth a look? People can come up with bogus ideas faster than you can find flaws in them if you're barred from using tests like "does it conserve energy and/or momentum".
so in my view there must be an escape of momentum that we haven't figured
But we already understand the mechanisms for such things. You can synthesize mass from energy and then accelerate it, or just generate photons (which have momentum) and dump them out the back. But we know what the theoretical maximum efficiency for those is too. And the thrust here is too high. And if the thrust is too high, then it's a perpetual motion machine.
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.
The problem with the paper is twofold:
1) After one year, it is still not published in a peer reviewed journal. This happens on occasion. However:
2) The data is about as flakey as it gets. Eg. the forces measured for the 60W power level range from 40 micronewton to 120 micronewton. This goes completely unexplained and all they do in the paper is some statistics voodoo to get some nice looking numbers out of this mess.
And yet, it does seem to work.
The main takeaway here is that if it really does works we have no idea on how. Zero. Nil. Nada. Worrying about conservation of momentum/energy when when don't really know what physical process is at play here does not make sense - for all we know we live in the aether and the device materializes invisible paddles to row it.
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.
"for all we know we live in the aether and the device materializes invisible paddles to row it."
We do live in the aether. The qualitative description of modern quantum field theory is pretty much indistinguishable from qualitative descriptions of some aether theories. Relativity suggests that you can't paddle through the aether, but one of the theories for how this thing works is essentially that.
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