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EmDrive: NASA Eagleworks' Peer-Reviwed Paper Is On Its Way (ibtimes.co.uk)
An anonymous reader quotes a report from International Business Times UK: An independent scientist has confirmed that the paper by scientists at the NASA Eagleworks Laboratories on achieving thrust using highly controversial space propulsion technology EmDrive has passed peer review, and will soon be published by the American Institute of Aeronautics and Astronautics (AIAA). Dr Jose Rodal posted on the NASA Spaceflight forum -- in a now-deleted comment -- that the new paper will be entitled "Measurement of Impulsive Thrust from a Closed Radio Frequency Cavity in Vacuum" and is authored by "Harold White, Paul March, Lawrence, Vera, Sylvester, Brady and Bailey." Rodal also revealed that the paper will be published in the AIAA Journal of Propulsion and Power, a prominent journal published by the AIAA, which is one of the world's largest technical societies dedicated to aerospace innovations. Although Eagleworks engineer Paul March has posted several updates on the ongoing research to the NASA Spaceflight forum showing that repeated tests conducted on the EmDrive in a vacuum successfully yielded thrust results that could not be explained by external interference, those in the international scientific community who doubt the feasibility of the technology have long believed real results of thrust by Eagleworks would never see the light of day.
How does the energy efficiency of this drive compare to a normal rocket?
If it works as advertised, it violates the law of conservation of energy, so its energy efficiency can be infinite.
(it produces a force with no reaction mass. Since energy is 1/2 mV^2, power is force times velocity, and thus the change in energy (per unit time) is proportional to velocity. So, if it runs at a given power level to produce a given thrust level, you can get more energy out than you put in simply be starting out in motion.)
Could this allow interstellar travel, by humans, within a normal human lifespan? What kind of reletavistic effects happen at high speed? I would assume thrust would drop as you approach C.
Well, if it violates the theory of relativity, anything could happen, I guess. Right now the thrust level quoted is micronewtons, so it would take millions of years to get up to the speed of light. But if the machine works, even at all, all bets on physics are off.
http://www.geoffreylandis.com
For me, even when there seemed to be some effect, it was simply far, far too small. Well within experimental noise - and certainly nothing you're going to propel anything anywhere with.
I do not want your cheap brainburning drugs. They are useless for work. And I am a working man today.
Well within experimental noise - and certainly nothing you're going to propel anything anywhere with.
I agree I'm still far from sold on the EM drive. I want to see it working in a vacuum, away from earth's magnetic field, and I want an explanation for the physics behind it. But if there's new physics, then who can say what the eventual application will be? Our first experiments with radioactive materials made things a little warm and glowy (and poisonous) but then fast forward a few decades and we've got mushroom clouds and nuclear reactors.
We don't have a state-run media we have a media-run state.
Well, if it violates the theory of relativity, anything could happen, I guess.
The guy ("scientist"?), Roger Shawyer, who invented it claims that it's actually due to the theory of relativity that it works.
Yes, but their test results explicitly falsified that theory. They tested this. The device (was claimed to) produce thrust whether or not it had the asymmetry that Shawyer claimed was required by his theory
...I'm not a physicist, so I can't speak to whether his explanation makes sense.
I am a physicist. His explanation makes no sense.
"It is a good rule not to put overmuch confidence in a theory until it has been confirmed by observation. I hope I shall not shock the experimental physicists too much if I add that it is also a good rule not to put overmuch confidence in the observational results that are put forward until they have been confirmed by theory."
- Sir Arthur Eddington
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If you want to do some armchair physics, these forums are really interesting. https://forum.nasaspaceflight....
People are attempting to recreate the "thrust-less" momentum at home basically. Lots of skepticism, lots of optimism, but real numbers being thrown around.
We're almost past the point of whether or not it works and moving onto why it works.
First, "Sir Newton" is incorrect. If you're going to use "Sir", you have to go with "Isaac". "Newton" is correct, as is "Sir Isaac Newton".
Second, Einstein is more correct than Newton. Relativistic physics is pretty much the same as Newtonian for most practical purposes, but diverges under conditions Sir Isaac had no way to consider or test. We've tested relativity to death, and it's always at least as accurate, and in more extreme conditions much more accurate, than Newtonian physics. Meanwhile, we know that relativity is incomplete (we don't know how general relativity works on the quantum scale, for example), and presumably we'll eventually have even more accurate physics. It's conceivable that we'll get the laws of physics just right sometime, but it isn't happening right now.
"When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes