back to article Chinese boffins: We're testing an 'impossible' EM Drive IN SPAAAACE

A month after NASA published a paper suggesting a controversial electromagnetic engine design appears to work, Chinese eggheads claim they've had similar results – and have sent an EM Drive into space for testing. At a press conference this month, Dr Chen Yue, the head of the communication satellite division at the China …

  1. x 7

    I wonder who they stole the designs from...........

    1. Destroy All Monsters Silver badge

      FakeDesigns, Inc. a company registered in Unicorn Land

    2. Snowy

      No one had British inventor Roger Shawyer did not make a secret of the design?

    3. Mage Silver badge

      Historically,

      The USA is the biggest commercial exploiter of others IP (copies of Copyright items, patenting items that are patented or prior art, using others registered designs or prior art etc), since 18th C.

      They STILL don't pay royalty on performance rights on USA Radio.

      Ripped off Dickens and Tolkien.

      USA spies also provide designs to USA industry.

      China has stolen IP. However they also innovate more than USA.

      Most USA "innovation" isn't even innovation.

      1. Anonymous Coward
        Anonymous Coward

        Re: Historically,

        Well, we know of one poster here who works for the Chinese propaganda ministry. Here's some advice - you will rise through the ranks there higher if you avoid falling for the fictions yourself.

        1. nice spam database '); drop table users; --

          Re: Well, we know of one poster here who works for...

          And this Anonymous Coward works for the USA propaganda ministry, without any doubt.

    4. The Man Who Fell To Earth Silver badge
      Boffin

      @x 7

      N-Rays Inc. Their last "successes" were polywater & cold fusion, which they plan to mate with an EM drive.

  2. This post has been deleted by a moderator

  3. Destroy All Monsters Silver badge

    Many Bothans died to bring us this plot device

    I can't even hear it anymore.

    An long-winded explanation of the EM-Drive's absence of power: here

    Although if any physical (as opposed to practically usable) effects were indeed confirmed (a long shot), well, that would be interesting. Not holding my breath.

    "This technology is currently in the latter stages of the proof-of-principle phase, with the goal of making the technology available in satellite engineering as quickly as possible," said Li Feng

    I guess Alchemists' gold-generation procedures were in the latter stages of the proof-of-principle phase, too.

    1. vir

      Re: Many Bothans died to bring us this plot device

      Alchemists did made a few solid contributions in the direction of actual, real chemistry as well. I'm also interested to see if anyone can come up with a good explanation for the results that people are seeing but in the meantime, that doesn't preclude anyone from taking it for a (very low acceleration) spin.

      1. Destroy All Monsters Silver badge
        Windows

        Re: Many Bothans died to bring us this plot device

        What Alchemists did is not particularly relevant here.

        can come up with a good explanation for the results that people are seeing but in the meantime

        Here is one: UNKNOWN MEASUREMENT ERROR.

        This is a device into which you pump a LOT of energy and then check whether there is force at the boundary of the instrument sensitivity.

        Check out those measurements here: Measurement of Impulsive Thrust from a Closed Radio-Frequency Cavity in Vacuum

        In particular the graph at the bottom (hotlink).

        Shazam! Linear Curve Fit! (Why not logarithmic? It looks logarithmic to me!!) Now are those measurements of up to 80 micro-Newton consistent with an unknown systematic error source and a curve fit that is firmly on the y=0 line? Why, yes, absolutely!

        I don't even know why the authors suddenly descend into the Bohmian Interpretation of QM which is now residing solidly on the graveyard of ideas (predictions are different from standard QM), some old farts regularly trying to revive it notwithstanding... it's not very seriousvery crank.

        1. This post has been deleted by its author

        2. vir

          Re: Many Bothans died to bring us this plot device

          "What Alchemists did is not particularly relevant here."

          I beg to differ. While the alchemists' goal of transmuting base metal into gold is now known to be impossible (without a particle accelerator), they did manage to develop and refine procedures and equipment and also to make a few genuinely useful discoveries along the way. If the effects that are presently being observed turn out to be "unknown measurement error" as you state and which I believe to be the case as well, at the very least we will have characterized the source of error and will know how to correct for it in other (perhaps unrelated) experiments. I wouldn't be surprised to see some of the techniques and equipment setups used here to show up in tests of other drive technologies either.

        3. Rich 11 Silver badge

          Re: Many Bothans died to bring us this plot device

          What Alchemists did is not particularly relevant here.

          Then you probably shouldn't have made the analogy.

          1. Destroy All Monsters Silver badge
            Windows

            Re: Many Bothans died to bring us this plot device

            I said "This failed undertaking is akin to that failed undertaking and for both similar claims exist"

            The countpoint was "But alchemists succeeded elsewhere.". Which is irrelevant. Mr. inventor may be a good cook for example...

        4. Hardrada

          Re: Many Bothans died to bring us this plot device

          "Here is one: UNKNOWN MEASUREMENT ERROR.

          This is a device into which you pump a LOT of energy and then check whether there is force at the boundary of the instrument sensitivity."

          That would certainly be precedented. NOAA spent 30 years basing their global climate forecasts on instruments with tolerances that exceeded the entire reported trend:

          "Instrument quality varies from country-to-country. Surface temperatures can be recorded to within 0.5 degree C."

          (http://www.cgd.ucar.edu/cas/tn404/text/tn404_6.html)

          To anyone who says 'But it'll average out!,' go read the papers. There were uniform changes to large blocs of instruments, spotty documentation of exactly how large those blocs were or when the changes were made, no calibration documentation kept, and no blinds.

          There were notable upward biases, like the change from buckets to engine room intakes for sea surface measurements, with lots of wiggle room in setting the correction factors.

          There's more of the same over at NASA (http://climate.nasa.gov/evidence/):

          "Data from NASA's Gravity Recovery and Climate Experiment show Greenland lost 150 to 250 cubic kilometers (36 to 60 cubic miles) of ice per year between 2002 and 2006"

          ...out of 684,000 cubic miles, or 0.009% or the total. (I'm being generous. If we use their low estimate, it's only 0.005%.)

          "...while Antarctica lost about 152 cubic kilometers (36 cubic miles) of ice between 2002 and 2005."

          ...out of 7.2 million cubic miles, or five ten-thousandths of a percent. So in 2,000 years of melting at that rate, Antarctica would lose 1% or its ice volume.

          Those two figures were used to argue that a global net heat gain of 0.17% of the total greenhouse effect ("net absorbed" vs. "back radiation" here: http://bit.ly/2i5QgFq) is severe, but it's not a direct measurement of that. You have to assume a strong net positive feedback based on the instrumental data above, which was never designed for this.

          Some of the other points in that link over-state the degree of corroboration because they're non-independent. (They rely on the instrumental record.)

          Then there's Anderson's paleo-index, which is geographically non-representative (skewed toward land and coasts) and has no corrections for precipitation (which is increasing: http://bit.ly/2ipGBu2 ...and under-reported: http://bit.ly/2hjpckS) or methane distribution (skewed toward land: http://bit.ly/2i3AbOo).

          This is a long way of saying that while it's entirely possible that this 'reactionless drive' is just a measurement fluke, it's not fair to knock NASA's measurements unless you're ready to hold other areas of science to the same quality standard.

      2. Truckle The Uncivil

        Re: Many Bothans died to bring us this plot device

        There is a hypothesis - not Sawyer's - that seems to explain it. Since the hypothesis has predictive value and many predictions check out it might have theory strength soon.

        Google MiHsC as there is far too much for a post. Goodbye dark matter too.n

        1. This post has been deleted by its author

          1. maffski

            Re: Many Bothans died to bring us this plot device

            @Symon

            Lisa, in this house we obey the laws of physics.

            No problem with that. However, I must have missed the bit where we figured out what the laws of physics are?

            If the EM drive works then it doesn't go against the laws of physics - it just demonstrates that our understanding of those laws is incomplete, and as we already know that it shouldn't be be grounds for dismissing something out of hand.

            1. This post has been deleted by its author

              1. psychonaut

                Re: Many Bothans died to bring us this plot device

                @Maffski. "it just demonstrates that our understanding of those laws is incomplete"

                i dont think you'll find a physicist alive or dead that thinks our current understanding of the physical laws of the universe is anywhere near complete, and may never be.

                we strive to find the best model to describe the universe from the the data we observe.

                the best bits in science are "hmm, thats a bit odd"

                theres a common misconception that the public has that scientists think "yup, we know everything". its simply not the case. the best scientists are able to completely change their opinion because of new data or phenomenon - this really should apply to all scientists. if we thought we knew everything, there would be no point in doing experiments now would there??

                1. Paul Shirley

                  Re: Many Bothans died to bring us this plot device

                  @Maffski. "it just demonstrates that our understanding of those laws is incomplete"

                  We don't even know all the implications of the laws we think we understand. That remains the most likely end result here, that eventually someone will work out which 'understood' laws are responsible and we might even learn something new from it.

                  1. Peter2 Silver badge

                    Re: Many Bothans died to bring us this plot device

                    The scientific process basically just means that you try something and document it, and say "look, I did this like this and it worked!"

                    Anybody doubting that can run their own test.

                    You can then accept the results of that test, and then assume that if it worked that way once, it will do again. Then you can make guesses about why that happened, eliminate the guesses until you have a reasonable conclusion and then make things based on that evidence.

                    Anybody saying "I don't believe..." should be a priest, not a scientist. The scientific process is not massively more than a formalised term for "trial and error".

      3. Truckle The Uncivil

        Re: Many Bothans died to bring us this plot device

        Try the blog "Physics from the edge"

    2. Mage Silver badge

      Re: Many Bothans died to bring us this plot device

      Newton was an Alchemist.

      1. TitterYeNot
        Coat

        Re: Many Bothans died to bring us this plot device

        "Newton was an Alchemist"

        Yes, as well as proposing the classical three laws of motion and the law of universal gravitation, Newton came up with numerous other theories which are generally less well known.

        Take his Third Law of Emotion, for example - 'For every male action there is an opposed female over-reaction.'

        <Coughs>

        OK, OK, I'm going. Mine's the one with the big hole in the pocket, my copy of 'Philosophiæ Naturalis Principia Mathematica' seems to have dropped out...

        1. Esme
          Joke

          Re: Many Bothans died to bring us this plot device

          Hmmn.. I'll take your Third Law and posit an explanation;

          Malions tend to be more massive than Femions (well, they're generally larger and denser than Femions, so that's hardly surprising) so according to the conservation of momentum, if a Malion impacts a Femion, you'd expect the motion of the Femion after the impact to be larger than the motion of the Malion that caused it.

          But I guess that might be too logical for the pretty little heads of some of the male commentards here...

          <grins, ducks and runs>

        2. Anonymous Coward
          Anonymous Coward

          Re: Many Bothans died to bring us this plot device

          Alchemy later became chemistry.

          Also turning lead into gold and for that matter one element into another is a cornerstone of nuclear physics.

          Also a few "pseudoscientific" theories were later proved correct but normally after centuries.

          Not that a lot of them make any sense, for example polywater was later discovered to have been simple contamination.

          Also relevant: water memory was debunked conclusively however microbiological contamination could have explained some early results which later vanished when better experimental techniques were used.

          A good example was Galen: probably had the right ideas but couldn't test them so went for the "easy" explanation which worked well enough at the time.

          Interesting aside: The Russian physicists who discovered Sellotape X-rays were laughed at by Western physicists, thus giving them a strategic advantage when it did finally get tested.

      2. Anonymous Coward
        Anonymous Coward

        Re: Many Bothans died to bring us this plot device

        > Newton was an Alchemist.

        The last of the Alchemists.

        Nothing came out of his alchemical side.

        Instead he is remembered for the mathematical physics foundation-laying genius.

  4. John Smith 19 Gold badge
    Go

    Some people think it sounds crazy, some don't

    But I'm kind of guessing that if the Chinese Academy is investigating it it's because

    a)Some very VIP has required them to.

    b)They know something others don't

    While it's possible it's I'd guess if there was any obvious way this could be shot down it would have already been done.

    Space is the logical place to test this and in principle a crewed station is an excellent position to do so. Let's see what happens./

    1. Anonymous Coward
      Devil

      Re: Some people think it sounds crazy, some don't

      There's another possibility. The Chinese might only be claiming they will test this drive in space, in order to get the West to waste resources on it. Meanwhile those wily orientals will have a nice private smile watching the fun.

      Hey, I'm just sayin'...

      1. Anonymous Coward
        Anonymous Coward

        Re: Some people think it sounds crazy, some don't

        "After fake rolex, the ghost towns and the hacking spree, now the physics mindfuck. Soon victory!"

      2. Lars Silver badge
        Happy

        Re: Some people think it sounds crazy, some don't

        "Hey, I'm just sayin'...". Much like with Trump, I would say, Big John. You have shown great belief in the Master. You have neatly written down all his promises and now I will promote you to my personal guard of promises. You can, I think, freely report about facts and fiction on this site. Apart from that all the best for next year for you and everybody else.

        1. Anonymous Coward
          Anonymous Coward

          Re: Some people think it sounds crazy, some don't

          Lars, please describe where I have "shown great belief in the Master." Personally I think you are showing great butt hurt, as the saying goes. I suppose I must be 'getting to you,' so I'll attempt to be more convivial when I debunk every rotten lie you try to propagate, okay?

        2. allthecoolshortnamesweretaken

          Re: Some people think it sounds crazy, some don't

          @Lars: you just had to wake him from his nap, didn't you. Don't you know by now that he'll be cranky all day?

          1. Anonymous Coward
            Anonymous Coward

            Re: Some people think it sounds crazy, some don't

            > "...you just had to wake him from his nap, didn't you. Don't you know by now that he'll be cranky all day?"

            Well, when some low-life starts trash-talking me personally with no provocation, my bullshit detector goes off. But no, I'm not cranky at all. People like that aren't really worth the trouble to get cranky over. I did however, ask Lars nicely to explain his unwarranted smear and you seem to be backing him up, so why don't you do it, @atcnwt?

      3. jaduncan

        Re: Some people think it sounds crazy, some don't

        "wily orientals"

        FFS.

        1. Anonymous Coward
          Anonymous Coward

          Re: Some people think it sounds crazy, some don't

          > "wily orientals"

          Okay, it's not PC, but that's what makes it funny. I prefer a world where we can all make jokes about each other without thin-skinned killjoys telling us we're bad to do so. I'm quite sure some of those East Asians employ colourful language when describing Caucasians.

          Besides, isn't "wily oriental" actually a kind of compliment? It implies high intelligence, don't it? And repeated IQ testing has shown that East Asians are near the top in IQ, beaten only by the Ashkenazim Jews. So yes, they are wily, and the rest of us had better be aware of that or they will eat our lunch.

          Good thing the US has so many East Asian immigrants...

          1. Alfred

            Re: Some people think it sounds crazy, some don't

            "I prefer a world where we can all make jokes about each other without thin-skinned killjoys telling us we're bad to do so."

            Good to know, you cock-gobbling child abuser.

      4. John Smith 19 Gold badge
        Unhappy

        "The Chinese might only be claiming they will test this drive in space"

        Quite correct.

        The Russians played this prank on the Americans in the 50's with the "nuclear powered bomber"

        The Americans played it on the Russians with SDI.

        Both with hilarious consequences as they say.

        The trouble is that for a good strategic deception (which is what these are) you need something that's

        a)Too important not to investigate

        b)Needs vast resources to do so. IE multi $Bn budgets in today's money.

        In principle an EM drive could be tested by a few cubesats. Say 1 for the drive and a couple to act as observers. Varying the shape of the chamber might need a couple more.

        I don't think there's any size limit either up or down. If you can make their thrust exceed say 2x the air drag (still the largest single force on a satellite below 1000Km, everything else is smaller) then all you have to observe is do they (or at least one of them) break orbit and start flying toward whatever you've aimed it at or not?

        Actually there is one high spec option which is to make the chamber walls superconductors. That would be really crank the price. You could spend $m on that.

        Still not really going to bring an economy to it's knees though, is it?

        1. Alan Brown Silver badge

          Re: "The Chinese might only be claiming they will test this drive in space"

          > The Russians played this prank on the Americans in the 50's with the "nuclear powered bomber"

          That "prank" might well have some unintended benefits (which should have materialised about 40 years ago) as it directly led to the development of LFTR technology in the 1960s.

          The ironic thing is that it's taking the chinese to take up a technology the americans explicitly threw away despite the obvious safety improvements over conventional water-moderated systems for the sake of congressional pork - and turn it into a viable commercial "thing"

          1. John Smith 19 Gold badge
            Unhappy

            "The ironic thing..the chinese to take up a technology the americans explicitly threw away"

            I looked up the history of this stuff a while back.

            Back in the 70's the US was looking for the next generation of reactors. Knowledge of the liquid salt reactor was mostly at Oak Ridge, while other labs knew more about the liquid Sodium fast reactor.

            The US put all its funds on the LMFR.

            Turned out Sodium is a real PITA compared to LBE (although I doubt the US knew this at the time), the world did not run out of Uranium a) Because it's got lots and b) Because reactors took longer and cost more to build than expected. AFAIK all the 2nd generation reactor designs had troubles. I'm not sure how many of them actually got built

            Then 3 mile island happened and US utility companies learned how you could turn a $1Bn asset into a $2Bn liability.

            So 40 years later the PWR remains the #1 reactor type on the planet, despite most of its design decisions being tailored for powering a submarine at 1/10 the size.

        2. Aodhhan

          Re: "The Chinese might only be claiming they will test this drive in space"

          No. A few 'cube' satellites is not enough to test the device.

          To make it viable, along with fueled propulsion, you need to get it to go over 25,000mph and maintain this speed.

          This is the speed required to break away from the Sun's gravitational effects. Otherwise, it will slowly lose speed and curve back towards the Sun like a comet.

          It takes approximately 18,000mph just to maintain an orbit around Earth without falling back. To break Earth's gravitational effects from its orbit, you need to push out over 20,000mph.

      5. rdhood

        Re: Some people think it sounds crazy, some don't

        That's not as crazy as it sounds. They could be making up press releases to expose who IS actually building one of these things, so they can hack them for the technology.

  5. Will Godfrey Silver badge

    Time for a change

    Well now, first put forward in England, given serious consideration by NASA...

    With the way they are developing their expertise in all things I reckon it's more than time to stop regarding China as a joke. In fact, these days it's the USA that's beginning to look like it will soon be wearing a clown outfit.

    1. Destroy All Monsters Silver badge

      Re: Time for a change

      Yeah at some point in time, we will be selling them the fried mars bar.

      1. Rich 11 Silver badge

        Re: Time for a change

        Fried, no. Deep fried, yes.

    2. allthecoolshortnamesweretaken

      Re: Time for a change

      Yeah, well, first put forward in Britain, first taken seriously by the USA, first successfully marketed by China - sounds par for the course. Based on this data alone, the EM drive is real allright.

    3. PhillW

      Re: Time for a change

      https://pbs.twimg.com/media/B0bQZhNCEAA_evZ.jpg

  6. Anonymous Coward
    Anonymous Coward

    One suggestion

    is that the energy being consumed causes the centre of mass to shift slightly. This is observed as motion.

    Doesn't Einstein confirm this ?

    1. Destroy All Monsters Silver badge
      Windows

      "This has happened before. And it will happen again."

      No, the energy consumed is radiated as heat.... why would the center of mass shift?

      This reminds me of the times of the "Woodward Drive":

      "The Alternate View" columns of John G. Cramer: Antigravity Sightings (March-1997)

      Honorably, tests were done and the idea abandoned.

      Note the following text in the above-linked article: Woodward's published measurements, which appear to have been done with considerable care, record a mass reduction of several milligrams as measured using signal averaging techniques to a statistical accuracy of 10 to 15 standard deviations. He also reports a number of systematic checks which are in good agreement with the predictions of his theory.

      Okay. The BBC would probably have been breathlessly reporting about new possibilities in Space Drive Technology...

      1. Anonymous Coward
        Anonymous Coward

        Re: "This has happened before. And it will happen again."

        I think it all started with the Dean Drive. How many successors has it had, I wonder?

      2. Vic

        Re: "This has happened before. And it will happen again."

        Honorably, tests were done and the idea abandoned.

        Tests have been performed on the "EM Drive".

        The one that most interested me showed a thrust when the power was turned on. Then, they rotated the equipment and tried again - the same thrust was seen in the same orientation.

        That puts the whole thing into the realm of "experimental error", AFAICS. I'd love to be proven wrong, but I'm pretty sure I won't be.

        Vic.

    2. DavCrav Silver badge

      Re: One suggestion

      "is that the energy being consumed causes the centre of mass to shift slightly. This is observed as motion.

      Doesn't Einstein confirm this ?"

      E=mc^2. If the object weighs one kilogram, the right hand side of this is 1 x (3 x 10^9)^2=9 x 10^{18}. That's a lot of energy, so you'd need a serious amount of energy to alter its centre of gravity in any measurable way.

  7. Kevin McMurtrie Silver badge

    Launch it!

    Nobody knowing 'if' or 'how' an EM Drive works sounds like the perfect reason to test it in space. At some point you need to stop staring at the testbed and go generate more data. The answer should be useful whether it works or not.

    1. Rich 11 Silver badge

      Re: Launch it!

      The answer should be useful whether it works or not.

      True, though perhaps only trivially so. It then becomes a matter of how much value you assign to the probability of success compared to the value of failure, and whether you're willing to invest that amount of money into a space-borne experiment.

      1. JLV

        Re: Launch it!

        Great thinking. That's also a metric that could be applied to our old friend the Man on Mars expedition. Luckily that hasn't consumed much $$$ to date, but it's bound to guzzle it as soon as NASA gets serious about it. Unless the space budget greatly expands, which I doubt, other space projects will suffer.

    2. Anonymous Coward
      Anonymous Coward

      Re: Launch it!

      Yes. This is how you do science. The hypothesis could be that the thrust is experimental error arising from an unknown earth based source and it won't work in space as predicted by all currently established theories. Testing it will probably prove this hypothesis correct. If however the hypothesis is proven wrong serious scientific progress have been made even perhaps disproving a long established theory.

    3. arctic_haze

      Re: Launch it!

      If you launch it and it does not show the expected effect, the proponents will say that it was made not according to the specs (2 mm too short and the alloy was slightly different). We will have demands to launch another one. And another. And another...

  8. hekla
    Holmes

    Ridiculous power for a result

    The EM-Drive uses a ridiculous amount of power for a result that is still not proved as statistical noise is bigger than the effect.

    For an EM-Drive to balance against gravity on Earth at sea-level (in vacuum if you insist) a small coin (such as 5p or 10c) it takes the power output of a medium national grid connected Nuclear Power Station.

    So Schrödinger and others suggest that a real result of force is yet to be achieved.

    1. JeffyPoooh
      Pint

      Re: Ridiculous power for a result

      1.2mN per kilowatt. Yes, that's arguably inefficient.

      The trick is that the equations work in either direction.

      Apply a force of 1.2mN, and out comes a kilowatt of power.

      Carefully place a heavy boulder on the wee feisty machine, and it would power a city.

      Hmmm...

      1. This post has been deleted by its author

    2. bombastic bob Silver badge
      Boffin

      Re: Ridiculous power for a result

      I expect that it's like shining a light to get thrust. rest mass of photons * speed of light = momentum change, or similar. It's incredibly inefficient because of the fact that the energy it takes to accelerate a propellant is proportional to the SQUARE of its velocity, but the momentum it generates is proportional to velocity NOT squared. So faster moving propellant, less efficiency. The propellant in this case is photons, which could be radiated from heating by the microwave, or could be the microwave energy itself. whatever, same effect.

      So, the most efficient rocket would accelerate 100% of its mass, one time, as the propellant. Not a very effective design. So yeah it's a balance between propellant mass and the energy it takes to accelerate it.

      the only way to get around this would be to generate gravity waves or graviton particles and make a warp bubble, which would eliminate the mass:mass interaction related to relativity, gravity, etc.. Yeah all that science-fictiony stuff. In theory you could create gravitons by spinning things [apparently at the center of a rapidly spinning disc you get a 'reverse gravity' effect that's barely measurable] though I expect that physical properties and required energies are the reason why we don't have warp drives yet...

  9. mr.K

    Anybody able to do the math for me?

    As I understand this the drive uses a lot of energy and a maybe a small amount of thrust. My question is, how does that amount of thrust compare to the amount you would get from simply sending the same amount of energy out as electromagnetic radiation in one direction.

    Also, I would like to know how easy it is to test in space. I am guessing it will go out in orbit, and there are a lot of forces acting on a craft there.

    Also, hats off to the scientists here that actually go out and test instead of dismissing something that their vast amount of knowledge and understanding dictates will not work.

    1. allthecoolshortnamesweretaken

      Re: Anybody able to do the math for me?

      Certainly a tangent, but this reminds me of David Brin's short story "Tank Farm Dynamo", which is freely availiable on Brin's website here.

    2. Flocke Kroes Silver badge

      Re: Anybody able to do the math for me?

      Force from emitting light: 3.3µN/kW. The xenon ion thruster on Dawn is 9mN/kW.

      Wikipedia's article on cold fusion mentions plenty of places where the fraud was investigated (the neutron spectrum graph 'changed' shortly after Pons was told his unreproduceable neutrons had the wrong energy). The cost of much of the research is not in the article, but for the research where figures are given, $71million was spent on cold fusion achieving nothing.

      Pons and Fleischmann understand electrochemistry and described their experiments clearly. They used calorimeters (notoriously inaccurate even in the hands of experienced professionals) which led to the early positive results from students around the world. They described melted electrodes (dissolving that much hydrogen in platinum is going to change its physical properties). They tried to use neutron detectors (read the instructions and budget at least a month trying to reduce noise down to something sane before thinking about trying to measure neutrons from your experiment).

      The EM drive descriptions I have read either contained mind bogglingly dumb errors in the algebra or were vague well passed the point of uselessness. There were pages of 'this is really amazing' followed by more pages of 'they are all being mean to me' before I got as far as the deliberate misquotes of NASA employees talking to journalists. This well was thoroughly poisoned long ago. Given the background, it is amazing that NASA spent any time on this experiment at all. NASA used sensitive equipment and took time to identify and cancel out as many sources of error as was possible with the limited time available. I am curious about where there error is, and hope it is something more interesting than someone not plugging the GPS into the atomic clock properly.

      1. Destroy All Monsters Silver badge
        Thumb Up

        Re: Anybody able to do the math for me?

        Listen to the Kroes!

        > The xenon ion thruster on Dawn is 9mN/kW.

        And that's from accelerating stuff coming from a tank mounted on the spacecraft and asking Mother Nature to please conserve momentum, as is the local custom.

      2. beast666

        Re: Anybody able to do the math for me?

        IslandPlaya agrees. It doesn't work. Bunch of crackpots.

    3. IT Poser

      Re: Anybody able to do the math for me?

      It's in the NASA paper. Assuming, and we all know the meaning of this word, no measurement errors the EMdrive is a couple of orders of magnitude better that a flashlight.

      I'd bother to look up the exact numbers from the paper but I'm fairly certain the measurements are inaccurate. I hope my belief is wrong so we start putting some serious power stations in space. We should be doing this anyway but it seems we need more motivation to get the funding in place.

      1. Destroy All Monsters Silver badge

        Re: Anybody able to do the math for me?

        Well, I hear the US has found lots of money in an underground vault and Reagan-era SDI with space lasers and all that is baaaack. So who knows...

  10. Lars Silver badge
    Happy

    Roger Shawyer

    Who is that guy, born when, where, education and so forth. Using the Wikipedia you get https://en.wikipedia.org/wiki/RF_resonant_cavity_thruster

    Interesting stuff, lots of people and countries involved but nothing about that person. And no, I am not Linkediting no more than Facebooking.

    1. Uncle Slacky Silver badge

      Re: Roger Shawyer

      There's some background here which seems pretty accurate from what I know of him from other sources. It may have been lifted from an earlier version of his Wikipedia page:

      http://alchetron.com/Roger-Shawyer-410658-W

  11. redpawn Silver badge

    Nothing but the universe comes for free

    This engine won't work well because energy is equivalent to mass. A charged battery has slightly more mass than a discharged one by E = mc^2. The mass lost is quite small but not nonexistent so it could be used for thrust in the production of EM waves. The EM waves as energy also have an equivalent mass so thrust can be produced but not for free.

    Feeding the engine with energy will be the problem. A very small mass loss will amount to very small thrust and good luck converting any significant mass to energy without bowing up.

    1. bombastic bob Silver badge

      Re: Nothing but the universe comes for free

      "The mass lost is quite small but not nonexistent so it could be used for thrust in the production of EM waves."

      exactly. shine a light, and you accelerate the opposite way in space, with nothing to stop it from working. problem is, photon rest mass is tiny, and it just takes too much energy to make them [compared to the tiny thrust they provide].

      "impulse drive" indeed.

      1. Destroy All Monsters Silver badge

        Re: Nothing but the universe comes for free

        > photon rest mass is tiny

        The consensus is that it is 0. That's pretty tiny.

        Momentum however, is > 0. Which is why "photon drives" work at least in principle.

      2. Chemist

        Re: Nothing but the universe comes for free

        "photon rest mass is tiny,"

        Photon rest mass is zero !

        1. Anonymous Coward
          Anonymous Coward

          Re: Nothing but the universe comes for free

          I thought photons never rested.

          1. Frumious Bandersnatch

            Re: Nothing but the universe comes for free

            They don't, but any useful measure of mass has to ignore (or decouple) mass due to acceleration. Since photons travel at the speed of light, they either have infinite energy or zero rest mass. The second option is the only one that makes sense. That's because it takes infinite energy to accelerate a massive object to c, even if the mass is tiny, since a fraction of infinity is still infinity.

  12. Death Boffin
    Boffin

    The best theory I have seen of how it works can be found here: https://arxiv.org/abs/1604.03449

    Makes for interesting reading. As far as I can tell the theory of operation implies that the universe is not a closed system, neatly sidestepping the First Law of Thermodynamics.

    A criticism of the idea can be found here: https://arxiv.org/abs/1506.00494

    It will be interesting to see how this plays out.

    1. Destroy All Monsters Silver badge
      Paris Hilton

      > "The model predicts thrusts of: 3.8, 149, 7.3, 0.23, 0.57, 0.11, 0.64 and 0.02 mN"

      I think that should be uN?

  13. allthecoolshortnamesweretaken

    IF the EM drive should actually work I'd say we* will find that it doesn't break Newton's third law of motion as such, but somehow isn't within it's jurisdiction, so to speak.

    * Where 'we' means the boffins that actually do the work whereas I will be reading a conveniently dumbed down article in a popular science magazine. As Ronald Balfour Corbett CBE used to say in that one sketch, I know my place.

    1. DropBear
      Trollface

      Oh, just wait until EM-roasted giant space-pigeons start falling through from another dimension, that's when the real fun begins...

  14. Anonymous Coward
    Anonymous Coward

    There is one born every day...

    Now all that remains is to combine this reactionless drive with a bottomless energy source, such as a General Fusion reactor or Black Light power module. After all, if you violate one fundamental symmetry in nature, why not break a few more!

    Personally, I am with P. T. Barnum on this one. It is a science-based scam, one of the many going on today. It is depressingly easy to con professional scientists: we are not trained to deal with an intentional, wilful deception.

    1. This post has been deleted by its author

    2. Wilco

      Re: There is one born every day...

      I don't think it's a scam, because there's no mark, and there's no payoff. It might be wrong, but having followed this for a long time, I think it's most probably either genuinely wrong or genuinely right.

      Black Light Power is more likely to be a scam, because they've been tapping investors for large sums of money for a really long time. However their recent results are certainly intriguing.

      And yes, if you combine a working emDrive with an efficient BLP you can get to the outer solar system in months, the nearest star in a decade or two.

      The probability that both are real is low, but if it turns out that they are, then the future we were promised might just arrive before I pop my clogs.

      1. xeroks

        Re: There is one born every day...

        The golden rule when you're faced with a scam is: if you can't see the mark, try looking in the mirror.

        (I just made that golden rule up.)

  15. Flocke Kroes Silver badge

    What if ...

    My personal bet is the thrust turns out to be a measurement error, but lets call "a few mN" 5mN. Imagine three magic space ships, 500kg each (mass of New Horizons), launched from the ISS at the start of next year with 5mN of thrust. Lets race them against some copies of real space craft.

    2017 Apollo, The Sequel returns from the Moon by the 7th of January.

    2018 New Horizons 2 passes Jupiter in February.

    2019 Messenger 2 passes Venus in March.

    2020 Dawn 2 reaches Vesta in April.

    2018 Messenger 2 orbits Mercury in February.

    2024 Dawn 2 orbits Ceres in July.

    2026 New Horizons 2 passes Pluto in July.

    2042 Magic0 in a very low orbit around the Moon, ready to fire landing rockets.

    2055 Magic2 passes Mars

    2056 Magic1 passes Venus

    2067 Magic0 docks with the ISS

    2075 Magic2 passes Ceres

    2090 Magic2 passes Jupiter

    2092 Magic1 orbits Mercury

    2101 Magic2 passes Saturn

    2110 Magic2 passes Uranus

    2117 Magic2 orbits Pluto

    [Comparing Apples and Oranges: The other races are reasonably fair, but New Horizons could not possibly stop at Pluto and Magic2 needs a really big nuclear reactor that can last a century.]

  16. ilmari

    What I would want to know is:

    Assuming a 1 ton satellite with 10kW of solar panels,

    In low earth orbit, how much thrust do you need to easily and clearly distinguish the produced thrust from perturbations from earth's non-spherical gravity, air resistance and solar wind?

    How much in geostationary?

  17. Milton

    Curiouser and curiouser

    There are many excellent reasons to believe the emdrive can't work: but one must admit it is not only taking inordinate time for qualified specialists to debunk it, now a space agency has actually gone to the very considerable effort and expense of putting one in orbit. This is NOT the usual progress of bad science.

    While I tend to think subtle perturbation will still probably explain the effects seen (perhaps due to thermal issues, or Earth's own EM field) the developments so far do invite some reasonable questions, not least about the completeness of our understanding of quantum mechanics, vacuum energy and so on.

    1. Charlie Clark Silver badge

      Re: Curiouser and curiouser

      As others have noted, the comparison is the cold fusion nonsense: the time isn't spent debunking but in trying to replicate the experiment and possibly along the way discover flaws in equipment (fast neutrinos) or calculations.

      Theoretically there is no reason to give this "drive" any credence. But sometimes, just sometimes, it's worth trying the daftest of ideas just one more time. And a good scientist is one who's able to put aside his prejudices to do so. That said, this really is an expensive joke.

    2. Vic

      Re: Curiouser and curiouser

      it is not only taking inordinate time for qualified specialists to debunk it

      Not really.

      The basis of this "drive" is that everything we thought we knew about physics is wrong. Thus, to test it, we cannot rely on physics. That means someone needs to build one and put it (largely) outside a gravity well where the tiny forces alleged to be involved might have any significance. And that means getting funding.

      I think it's gone quite swiftly.

      Vic.

  18. Fun Fun

    It works this way:

    The other end of the cavity is narrower, thus the speed of microwave photons is slower there. The photons kick that side of the cavity less than the wider side.

    1. bombastic bob Silver badge
      WTF?

      Re: It works this way:

      "thus the speed of microwave photons is slower there"

      yeah, the 'venturi' effect except it's photons... no, wait.

      sounds just as plausible as any OTHER (B.S.) explanation, aside from just shining a light/heat and letting photon impulse push you the other way

      (you forgot the joke icon)

      1. Fun Fun

        Re: It works this way:

        Tell me why its wrong?

        1. Vic

          Re: It works this way:

          Tell me why its wrong?

          Because the size of the cavity does not change the speed of electromagnetic radiation; the central plank of your thesis is provably wrong.

          Vic.

          1. Fun Fun

            Re: It works this way:

            ok, yes, I see,

            But then why does light bend around sharp objects?

            1. Destroy All Monsters Silver badge

              Re: It works this way:

              Because probability waves.

              1. Anonymous Coward
                Anonymous Coward

                Re: It works this way:

                I recommend Feynman's "QED: The Strange Theory of Light and Matter": The . It's fun and fast. Also shows there's an outrageous lot of stuff going on underneath the pedestrian appearance of "practically Newtonian Physics".

  19. BoldMan

    Weightlessness does not negate friction. Friction is the interaction between two surfaces - if you didn't have friction you wouldn't be able to hold your knife and fork!

    What weightlessness does do is eliminate GRAVITY-based friction, ie something sitting on a table held against the surface by gravity and subject to friction because of the force of gravity pressing the two surfaces against each other.

    1. DropBear
      Trollface

      But of of curse you would. When was the last time you saw a kitchen utensil with a handle of perfectly uniform thickness along its length...?

  20. rocketjoe

    The Author says scientists need to understand how the EM drive works - not necessarily. For example: we use gravity every day but don't understand how it works, fundamentally. The Chinese are at least trying the tech in space to see if it works. If it does, they could start another "Space Race" to exploit the resources of the solar system first.

    1. Destroy All Monsters Silver badge

      Woah. From a far-out barely credible idea into "Space Neocolonialism" (what kind of resources are you going to exploit exactly and how and how is any of that a "race"?) in two sentences.

      Wake me up when O'Neill Spacestations are being dropped on Australia.

  21. Kaltern

    Damn I will laugh so hard if it actually works and opens up a hitherto unknown aspect of physics.

    And if it doesn't, at least SOMEONE actually took the time to try the fucking thing, rather than just bitch about how it cannot possibly work - without actually trying it.

    Scientific method is all well and good - but actual practical proof-of-concept trumps theory every single time.

    1. Destroy All Monsters Silver badge

      If you follow every harebrained scheme that's being laid in front of your doorstep, you will never get anywhere....

    2. Anonymous Coward
      Anonymous Coward

      "Probably not a problem"

      > Damn I will laugh so hard if it actually works and opens up a hitherto unknown aspect of physics.

      Since Half-Life (the game) at latest, we know that what opens are portals and these hitherto unknown aspect of physics are no laughing matter.

  22. MachDiamond Silver badge

    SETI

    My approach in competition with the Chinese would be to put more funding into SETI and just buy a reactionless drive from the Outsiders when we manage to make contact.

    1. Destroy All Monsters Silver badge

      Re: SETI

      FUND THIS!

      Of course they won't take T-bills or print-u-money from the Fed/ECB. They will want real goods. Handcrafted, finely painted pottery maybe? Walt Disney's frozen head? Destructive scans of good percentage of extant homo sapiens instances?

  23. Frumious Bandersnatch

    the engines, used in concert, may even power human exploration.

    I read this and I wondered if it was a Disaster Area concert.

  24. smartypants

    Good example of humans at work on an idea..

    Not the chinese experiment, but this debate.

    We have a wide spread of opinion, based on varying degrees of understanding of physics in general and previous attempts to investigate the claims of this type of device. There's a spread of supposed certainty about the chances of success, and a cloud of people like me that don't have the time or brain to have come to an informed understanding of the chances of this effect being real, but enjoy the outpourings of those who seem a bit more clued up, which is what makes El Reg worth visiting in the first place. (Note to El Reg: More techy articles in 2017!)

    And of course, it wouldn't be 2016 without a little bit of casual racism, stoutly defended as though it were a good thing, would it?

    Happy new year!

  25. x 7

    New Scientist article this week saying the drive doesn't work.

    It does produce thrust, but not through any EM effect

    1. x 7

      https://www.newscientist.com/article/2169809-impossible-em-drive-doesnt-seem-to-work-after-all/

  26. rdhood

    Might be cheaper...

    If the EM drive is small enough, it might be simpler and less expensive to just put one up and see what happens than to do the hard science and figure out why it does/doesn't work

  27. Anonymous Coward
    Anonymous Coward

    Random

    If there is measurable thrust, then this suggests a way to build a useful drive without knowing *why* it works just using iteration.

    Case in point: zapping Sr metal with blue lasers also works and is a heck of a lot cheaper and simpler than Xe based ion drives.

    Problem is that semiconductor lasers do not work well in space without mitigation of radiation damage.

    Maybe a N2/Kr TEA laser would be safer and actually doable as its all existing reliable technology?

    (scuttles off to Patent Office)

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