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Space China Technology

China's Radical New Space Drive 419

Posted by samzenpus
from the learning-to-fly dept.
First time accepted submitter Noctis-Kaban writes "Scientists in China have built and tested a radical new space drive. Although the thrust it produces may not be enough to lift your mobile phone, it looks like it could radically change the satellite industry. Satellites are just the start: with superconducting components, this technology could generate the thrust to drive everything from deep space probes to flying cars. And it all started with a British engineer whose invention was ignored and ridiculed in his home country."
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China's Radical New Space Drive

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  • by Electricity Likes Me (1098643) on Thursday February 07, 2013 @10:05PM (#42828451)

    The principles behind the EmDrive have serious theoretical problems, and the original builder and designer never tested it in a vacuum chamber.

    Taking a sealed container and pumping a few kilowatts of microwaves into it, chances are any thrust developed is actually air that's getting heated up and expanding out of the container. Unless the EmDrive has been put in a vacuum chamber where this can be demonstrated to definitely not be the case (i.e. low enough that their couldn't be enough reaction mass) then it's not actually working.

    • chances are any thrust developed is actually air that's getting heated up and expanding out of the container.

      That effect would not last long. If it produces continuous low thrust in atmosphere, that can't be it.

      More likely, as one of the groups that looked at this observed, is that all that RF (2kw) is simply interfering with the instrumentation.

      • by Electricity Likes Me (1098643) on Thursday February 07, 2013 @10:19PM (#42828543)

        The thrust is reported to be from the large end towards the small end. The entire body of this thing that's heating up from a few kilowatts of microwaves would be warming air that flowed over the surface and thus imparting energy to it and providing a source of thrust. It would easily provide continuous thrust.

        • by Jane Q. Public (1010737) on Thursday February 07, 2013 @11:40PM (#42828943)

          "The thrust is reported to be from the large end towards the small end. "

          No, TFA says:

          "... experiences a net thrust towards the wide end."

          • "The thrust is reported to be from the large end towards the small end. "

            No, TFA says:

            "... experiences a net thrust towards the wide end."

            "Thrust towards" is ambiguous. Dig through the website on the proposed theory [emdrive.com]. The implication is the force is exerted on the large end, so the contraption moves large end first.

            Which - again - is the same behavior you'd get from heating air along the length of the taper.

            • by Anonymous Coward

              Just get one of these things and test it under rigorous scientific conditions and scrutiny.

              If it works, it works; If it doesn't it's back to the drawing board and we can all move on.

              Al this fucking shitbrained arguing over nitpicky sematic points is just maddening. Put up or shut the fuck up, because we don't want to hear your not-based-on-anything-that-counts armchair scientist opinions.

              • by Electricity Likes Me (1098643) on Friday February 08, 2013 @06:51AM (#42830687)

                Just get one of these things and test it under rigorous scientific conditions and scrutiny.

                If it works, it works; If it doesn't it's back to the drawing board and we can all move on.

                Al this fucking shitbrained arguing over nitpicky sematic points is just maddening. Put up or shut the fuck up, because we don't want to hear your not-based-on-anything-that-counts armchair scientist opinions.

                "Just get one of these things"

                You know who has one of these things? The people who built it. You know what evidence they can't put up? The type which discredits a very obvious criticism. One would think with that type of headstart and knowledge of its operation and experience with test setups, this type of demonstration would be an obvious one.

              • by fractoid (1076465)
                Calm down, Randi. Anyone who understands the scientific method agrees with you, and we file this under 'that's nice, call back when you have data'. :)
              • Just get one of these things and test it under rigorous scientific conditions and scrutiny.

                If it works, it works; If it doesn't it's back to the drawing board and we can all move on.

                From TFA:

                Boeing's Phantom Works, which works on various classified projects and has been involved in space research, went as far as acquiring and testing the EmDrive, but say they are no longer working with Shawyer.

                So either it didn't work, or Phantom Works already has/came up with something better. On a related note, the article makes kind of a big deal about the "propellant-less" claim, even though we already have a propellant-less drive with extremely low thrust: solar sails. Although, admittedly you'd need a pretty huge sail to reach 720 mN (the claimed thrust) in Earth orbit. Actually, 720 mN is quite large compared to current ion engines, so I'm curious to know what Phantom Works found.

      • Mach-Woodward Effect (Score:3, Informative)

        by sanman2 (928866)

        Well, that's what people have said about the Mach-Woodward experiments, but an opposed piston design is now being tried out to isolate any noise-producing effects for remediation:

        http://arxiv.org/abs/1301.6178 [arxiv.org]

    • chances are any thrust developed is actually air that's getting heated up and expanding out of the container.

      Sure but what if this turns out to be an efficient way to turn a small amout of gas into high energy reaction mass, with a high specific impulse?

    • Re: (Score:3, Informative)

      by Anonymous Coward

      FTFA:

      > Shawyer continued to produce and test more advanced demonstrators, working out elaborate ways of ensuring that the test results are valid and not the result of air currents, friction, ionization, interference or electromagnetic effects.

    • by Dan East (318230) on Thursday February 07, 2013 @10:19PM (#42828539) Homepage Journal

      Some rather talented scientists evaluated this first hand:

      Boeing's Phantom Works, which works on various classified projects and has been involved in space research, went as far as acquiring and testing the EmDrive, but say they are no longer working with Shawyer.

      I'm sure if the drive was useful in any meaningful way it would have been utilized. So this does not bode well for the practicality of the drive for real-world applications.

      • by tqk (413719) <s.keeling@mail.com> on Thursday February 07, 2013 @10:52PM (#42828727)

        I'm sure if the drive was useful in any meaningful way it would have been utilized.

        Kind of like if Robertson screws were better than Phillips screws, they would have been utilized by Henry Ford? That stuff often doesn't work out the way sane people think it ought to.

      • Re: (Score:3, Insightful)

        Phantom Works just said they're not working with Shawyer. They didn't say the drive doesn't work. Given their nature, if the drive did work, they wouldn't disclose that because it would have profound advantages for classified work (e.g. KH-11/KH-12/etc. spy satellite maneuvering).
        • by mbone (558574)

          No, given their nature, if it worked they would be producing glossy brochures showing spacecraft flying to Mars or where-ever. There is no reason why they would keep this a secret; the spy satellite world is not suffering from a lack of reaction mass. If they even thought it possibly could work, they would hire Shawyer.

          • They wouldn't if Shaywer had independently produced something that Boeing had already developed as part of a black project.

          • by Forever Wondering (2506940) on Friday February 08, 2013 @01:49AM (#42829549)

            No, given their nature, if it worked they would be producing glossy brochures showing spacecraft flying to Mars or where-ever.

            While that might be true for Boeing in general, for true black project departments, this is a no-no. For example, at Perkin Elmer, which was doing the engineering for the KH-9, one of the engineers had a heart attack on the job and died. The other engineers were not permitted to tell the guy's widow even how he died (e.g. peacefully, etc.) until after the project was declassified some 25 years after the last KH-9 was decommissioned. That's how secretive they can be.

            There is no reason why they would keep this a secret;

            Once again, I think you underestimate just how deep and dark these projects sometimes are.

            the spy satellite world is not suffering from a lack of reaction mass.

            Most KH satellites don't just go around in a fixed [polar] orbit. Their orbits must be constantly adjusted so they can observe a trouble spot in real time (e.g. they can't wait 5 days for the orbit to pass over the spot naturally--they must burn fuel to change the orbit so it's in the right place on the next pass). Considerable mathematical effort is expended in the orbital adjustment calculations, designed to minimize the fuel cost of adjusting the orbit. Sometimes, compromises have to be made, to conserving fuel cost against getting there ASAP. Having a satellite that has no such downside, would be a [closely guarded] strategic advantage.

            If they even thought it possibly could work, they would hire Shawyer.

            Given that he's a U.K. citizen, it's unlikely he could get the security clearance necessary. Or, the Phantom Works people had reservations about him specifically, for whatever reason (e.g. either his general ability to work well with others, or his desire to keep his work public--to name just a few).

      • by number11 (129686)

        Boeing's Phantom Works, which works on various classified projects and has been involved in space research, went as far as acquiring and testing the EmDrive, but say they are no longer working with Shawyer.

        I'm sure if the drive was useful in any meaningful way it would have been utilized.

        Maybe (though Western Union first dismissed the telephone as a worthless toy). But note that they didn't say they weren't using the drive, or principles thereof. They just said they weren't working with Shawyer. If it's classified, who would know if you were infringing on a... does Shawyer even have a patent?

      • by dbIII (701233) on Friday February 08, 2013 @03:14AM (#42829855)

        I'm sure if the drive was useful in any meaningful way it would have been utilized

        I first saw a working model of a scramjet in 1986. It wasn't the first one. now it's 2013 and it hasn't been "utilized" yet in a "real-world application" but it is on track to do so. That should show you that you can't expect instant results with propulsion systems and that your assumption that something is worthless if you don't get quick results is wrong. Instead the thing itself has to be considered on it's own merits and not whether it's on the shelf at Walmart yet. There are plenty of reasons why Boeing may not immediately jump on a new and unproved technology that have nothing to do with whether it's viable or not. We'll need to get information from another source instead of just making a wild assumption based on it not being commercially available this instant or other unreasonable expectations.

        • by Rockoon (1252108)
          The difference is that the idea of a scram jet came well before the implementations because the idea was theoretically sound. The theory preceded the implementation.

          This device, on the other hand, seems to be an implementation before there is a theory of how it could possibly work in a vacuum. In other words, we should most certainly be skeptical of what the supposed observed results mean because it simply doesnt make any theoretical sense that it would work in a vacuum.

          Consider the team that reported f
    • by Andy Prough (2730467) on Thursday February 07, 2013 @11:22PM (#42828865)
      The FAQ deals with conservation of momentum, allowance for bouyancy, electromagnetic effects, convection and other issues here: http://emdrive.com/faq.html [emdrive.com]. A fantastic picture of the device on this page: http://emdrive.com/ [emdrive.com].

      Here are some of the FAQ answers:
      Q. Why does the EmDrive not contravene the conservation of momentum when it operates in free space?
      A. The EmDrive cannot violate the conservation of momentum. The electromagnetic wave momentum is built up in the resonating cavity, and is transferred to the end walls upon reflection. The momentum gained by the EmDrive plus the momentum lost by the electromagnetic wave equals zero. The direction and acceleration that is measured, when the EmDrive is tested on a dynamic test rig, comply with Newtons laws and confirm that the law of conservation of momentum is satisfied.

      Q. Are there any convection currents which might affect the results?
      A. Convection currents did not affect the results, as measurements were taken with the thrust vector up, down and horizontal. Test runs were also carried out using a thermal simulation heater to quantify the effects of change of coolant temperature.

      Q. Have electromagnetic effects been taken into account? These include interactions between current-carrying conductors and between such conductors carrying RF currents and nearby metallic structures in which currents might be induced.
      A. Stray electromagnetic effects were eliminated by using different test rigs, by testing two thrusters with very different mounting structures, and by changing the orientation by 90 degrees to eliminate the Earth’s magnetic field.
  • by phantomfive (622387) on Thursday February 07, 2013 @10:07PM (#42828467) Journal
    How about this headline: "Discredited British Engineer Finds New Scam Victims in China." His invention is "a closed, conical container which, when filled with resonating microwaves, experiences a net thrust towards the wide end." Sounds realistic.
  • ...you'd think that if high energy in a closed, conical microwave cavity produced thrust, someone would have noticed before this. We've done a lot of work with microwaves.

    • ...you'd think that if high energy in a closed, conical microwave cavity produced thrust, someone would have noticed before this. We've done a lot of work with microwaves.

      Of course it does, there are photons coming out of it.

    • by tqk (413719)

      ...you'd think that if high energy in a closed, conical microwave cavity produced thrust, someone would have noticed before this. We've done a lot of work with microwaves.

      "You'd think that if the world were a sphere circling the Sun, someone would have noticed before this." I imagine Copernicus hearing something along those lines, then Galileo.

  • Doesn't work (Score:5, Insightful)

    by joe_frisch (1366229) on Thursday February 07, 2013 @10:20PM (#42828549)

    From the article: "Seems to violate law of conservation of momentum". - Yup it does. Imagine putting an invisible mass-less box around the entire system. Almost nothing comes out the back (only microwave energy - more on that later). The center of mass of the box accelerates. This is a violation of conservation of momentum - one of the most well understood and best tested laws in physics. If there were some exotic high energy physics effect proposed for this at least it might be worth listening, but this is just electromagnetism - very well understood. The "group velocity / phase velocity" is just jargon that has nothing to do with this since it is the Poynting vector that carries momentum.

    You CAN make a reaction drive using photons (microwaves in this case), this idea has been around for many decades. The problem is that photons carry a lot of energy relative to their momentum so it takes an enormous power source to produce any thrust. So far no one has found a practical application where there was a large enough energy (and high enough power ) source to make this practical.

    There have been a lot of experiments with microwaves - I've personally worked on a 600MW pulse microwave system. There have even been attempts at microwave driven spacecraft sails. Some early experiments seemed to indicate more thrust than would be expected from momentum conservation. Eventually this was tracked down to gas absorbed on the surface being heated and released by the microwaves - essentially a conventional rocket. With very high microwave powers you can generate forces in all sorts of ways in a closed laboratory environment that would not work in space.

    This will not work.

    • by Guy Harris (3803)

      From the article: "Seems to violate law of conservation of momentum". - Yup it does.

      And from the article, in more detail: "It seems to violate of the law of conservation of momentum, implied by Newton, which says that no closed system can have a net thrust. However, Shawyer says net thrust occurs because the microwaves have a group velocity which is greater in one direction than the other and Einstein's relativity comes into play."

      Is the article and/or Shawyer trying to say here that "Einstein's relativity" magically makes the law of conservation of momentum go away (perhaps the idea is t

      • Re:Doesn't work (Score:5, Interesting)

        by joe_frisch (1366229) on Thursday February 07, 2013 @11:01PM (#42828769)

        Conservation of momentum is extended in relativity to conservation of 4-momentum, basically a combination of momentum and energy. In a rest frame this means that standard Newtonian momentum is conserved, it just makes conservation also work when you are observing a system that is moving past you at relativistic speeds.

      • by rufty_tufty (888596) on Friday February 08, 2013 @06:52AM (#42830691) Homepage

        It's not a device for extracting momentum from the relativistic differences between the group and phase velocity of resonating microwaves.
        It's a device for extracting money from people who don't understand physics.
        I would call this device a total success so far.

    • Re: (Score:3, Insightful)

      by tibit (1762298)

      And for everyone still reading: that's where it all ends. Nothing more to be said. Anyone who's not deluded understands that seeing any measurable thrust in such experiments is a prima facie evidence that your experimental method is broken. The better your experiment, the less thrust you should measure. That's all there's to it. Undergrad physics lab, it sounds like -- to me at least.

      There's also some indirect evidence of fraud, even if non willful. How the heck is it that all such "genius", "unappreciated"

      • I'd agree with all that except that its actually tricky to do the experiment correctly. With lots of microwave power, high currents, etc in the system it would be easy to fool yourself. Of course if you have any brains you know it can't work from first principals and wouldn't' bother trying.

        • Re:Doesn't work (Score:4, Insightful)

          by tibit (1762298) on Thursday February 07, 2013 @11:46PM (#42828969)

          I do know that it's tricky to do this stuff correctly, that why you should doubt yourself more when faced with supposedly extraordinary results. Doubt more, not less. All I remember from numerous labs that extraordinary results meant you'd have to keep redoing it until it got ordinary again. I'd have really thought that people who did any sort of engineering or physics undergrad labs should have had such basics explained to them. I'm playing with getting the 4th digit to agree well with theory in a simple mechanical pendulum, and the dreaded thing highlights that everything you thought could be ignored, can't. You have to engineer it to work -- look at all the numbers, for all effects you can think of, estimate their magnitudes, verify that you do in fact see the effects, and then mitigate. Good old experimental engineering. You get small but cumulative payoffs for diligence and a certain sense of accomplishment -- I do at least. Simple life's pleasures :)

          This non-drive, given the power pumped into it, simply magnifies all the effects people can ordinarily ignore. It's a nice educational tool. I think good schools should add such a thing to their lab curriculum, so that the students will get some experience in how easy it is to fool oneself. There are probably other similarly spectacular experiments that would serve the same purpose, of course -- even a basic large mechanical pendulum.

          I can't get over the fact that people with money who fund that sort of thing are so gullible, though. I mean, give me a fucking break, they seem to be just as gullible as the investors were 100+ years ago when faced with all sorts bullshit when the telegraph, telephone and electricity were getting into high gear. Hans Camenzind's little jewel of a book "Much ado about almost nothing. Man's encounter with the electron" is a sad testament to how little things change in that respect. The dumb will be parted with their money, all the time, all the same.

    • Bravo, Joe. It's another water carburetor, and your explanation is succinct and to the point. Props.

    • Since when is magnetism a closed system within range of the Earth or Sun?

    • I've personally worked on a 600MW pulse microwave system.

      Yes, but did you work with resonating microwaves? Clearly that is how this guy can violate the law of thermodynamics (I would mock you now but my sarcasm wouldn't come through).

      • In fact the 600MW were used to drive microwave resonators (X-band accelerator structures). Not only that but they had different group and phase velocities. I guess I should be surprised they didn't launch themselves into low earth orbit....

        Maybe we should have used Tesla coils instead,

  • by PPH (736903)

    So they found the guy who invented the Triumph?

  • http://emdrive.com/principle.html [emdrive.com]

    The inevitable objection raised, is that the apparently closed system produced by this arrangement cannot result in an output force, but will merely produce strain within the waveguide walls. However, this ignores Einstein's Special Law of Relativity in which separate frames of reference have to be applied at velocities approaching the speed of light. Thus the system of EM wave and waveguide can be regarded as an open system, with the EM wave and the waveguide having separa

    • by steveha (103154)

      I want it to be true, but I'd bet against it:

      http://xkcd.com/955/ [xkcd.com]

    • There is a description of the Sagnac effect on wikipedia, this is the basis of a laser gyroscope. Interestingly Newtonian physics and relativity give the same answer for this. I isn't related to the microwave drive. I think they mention it because laser gyroscopes are conceptually complicated and they hope that the reader won't understand them, and therefor not understand that if anything they are yet more evidence that this trick doesn't work.

  • by DerekLyons (302214) <(fairwater) (at) (gmail.com)> on Thursday February 07, 2013 @10:47PM (#42828711) Homepage

    From TFA: Propellant can account for as much as half the launch weight of a geostationary satellite. This means that, in principle, fitting one with an EmDrive rather than a conventional drive, could halve launch costs.
     
    That depends entirely on the power system needed to operate the drive. That's the real Achilles heel of various non chemical propulsion systems - they eat a lot of juice and the resulting power supplies negate most (if not all and then some) of the savings of not carrying conventional fuel.

    • by mosb1000 (710161)

      They say the existing unit uses about half as much power to produce 4 times the thrust of the ion drive.

  • It doesn't sound very sophisticated, are there plans anywhere so I can build one and see for myself?

  • by aussersterne (212916) on Thursday February 07, 2013 @11:26PM (#42828887) Homepage

    experiment (since IANAP), I do want to say that there seems to be a troubling trend amongst the best and the brightest in many STEM fields to mistake theory for reality. Theory is great and proceeds under the scientific method from empirical observation, but as we've seen throughout history, new phenomena and corner cases to arise and require theory to be amended.

    It's fine to say "this is clearly unlikely to work under current theoretical understandings" but let's also refine and do the experiments to the best of our ability so that science remains scientific (i.e. nominally empirical and ultimately practical in nature). There's a difference between taking "current theory suggests this is likely to fail" as a statement of fact and mistaking theory instead to be *evidence* about experimental outcomes.

    No theoretical argument can be evidence for the reality or unreality of phenomena, no matter how well-formed. That's not to say that we ought to mistake the phenomena at issue—it's obviously critical to be able to understand, rather than misconstrue, the reality that we observe—only that sometimes a generation or two of scientists seem to get complacent and imagine that they've got the world all figured out after all.

    Let's continue to do, and—to the best of our ability and within reason (but with "within reason" here broadly defined—allocate resources for, actual experimentation and empirical observation of the world around us.

    Not that we don't—but to my eye, the attitude that if theory doesn't support it, it's always a waste of money to test it out experimentally, is a dangerous one for the future of a science that is far less uniform, linear, and accumulative in its progress than we often tend to remember.

    • by j-beda (85386) on Friday February 08, 2013 @12:09AM (#42829053) Homepage

      experiment (since IANAP), I do want to say that there seems to be a troubling trend amongst the best and the brightest in many STEM fields to mistake theory for reality. Theory is great and proceeds under the scientific method from empirical observation, but as we've seen throughout history, new phenomena and corner cases to arise and require theory to be amended.

      While it is certainly worthwhile to keep an open mind and question our assumptions, there are a variety of different levels of confidence we have in different ideas. The major conservation laws (linear momentum, energy, angular momentum) are mathematically equivalent (via Noether's theorem) to symmetries of the space. If the laws of motion are independent of position then linear momentum is conserved. If linear momentum is not conserved, than the laws of motion are not independent of position. (similarly for rotation invariance angular momentum conservation and time invariance conservation of energy).

      http://en.wikipedia.org/wiki/Noether's_theorem [wikipedia.org]

      So this goes way beyond understanding of EM theory - if we have a case where momentum is not conserved, that will fundamentally change how we think the universe is put together. In my mind it is much much much more likely that there is error or fraud or psychosis than momentum is not being conserved.

      • by joe_frisch (1366229) on Friday February 08, 2013 @12:34AM (#42829175)

        Agreed.

        Also just trying random stuff to see what happens is likely to end up with experiments that are subject to all sorts experimental errors. If you have a theory that electromagnetic radiation doesn't conserve momentum, then you design a specific experiment to look: If you think its a high field effect, you do particle collisions, or relativistic particles in intense laser beams. If you think its a small but linear effect you do superconducting microwave cavities suspended on ultra-sensitive force balances. You don't start out trying to build a rocket engine.

    • by gweihir (88907)

      Please stop the BS. The effect you describe does not exist. We just know enough with high probability that a lot can be ruled out. There is room for residual uncertainty, i.e. deviation between theory and reality, but it is not large.

    • And the most annoying tendency amongst people outside of STEM disciplines is the conflation of the terms hypothesis and theory.

  • BS (Score:4, Funny)

    by mbone (558574) on Thursday February 07, 2013 @11:31PM (#42828907)

    All the usual signs of pseudoscience.

    Show it works (note : that is not the same as saying that you have shown it works), and I'll be interested. Until then, this goes in the cold fusion circular file.

  • Is it non-sense time again? Flying cars are a bad idea for a large number of reasons. Those that still ignore this are not qualified to report on anything in science or technology.

  • by Bob Hearn (61879) on Friday February 08, 2013 @12:46AM (#42829217) Homepage

    ... sort of. And it is established physics. See Swimming in Spacetime: Motion by Cyclic Changes in Body Shape [mit.edu], Science, 2/27/2003, by Jack Wisdom.

    But this mechanism relies on general relativistic effects, and only works in curved spacetime. Momentum conservation is not violated, because while the location of the object changes, its momentum (thus velocity) does not -- it simply cyclicly translates itself through space.

    My first thought reading about the EmDrive was that Shaywer had found a way to reproduce this effect using a microwave cavity. But unless I'm mistaken, this does not appear to be the case, and I don't follow the arguments that Shaywer's drive should work.

  • what? (Score:5, Funny)

    by jafac (1449) on Friday February 08, 2013 @01:35AM (#42829479) Homepage

    I find it hard to believe that the Nation that is home to the Ministry of Silly Walks has ridiculed a scientist for his strange ideas. . .

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