Did NASA Validate an “Impossible” Space Drive? In a Word, No.

Aug 9, 2014

By Corey S. Powell


Physicist John Baez has another, more colorful word to describe the spate of recent reports about a breakthrough space engine that produces thrust without any propellant. The word starts with “bull–.” I won’t finish it, this being a family-friendly web site and all. Baez himself has softened his tone and now calls it “baloney,” though his sentiment remains the same: The laws of physics remain intact, and the “impossible” space drive is, as far as anyone can tell, actually impossible.

The story begins several years back with a British inventor named Roger Shawyer and his EmDrive, a prototype rocket engine which he claimed generated thrust by bouncing microwaves around in an enclosed metal funnel. Since no mass or energy emerged from the engine, Shawyer’s claim was another way of saying that he’d found a way to violate the conservation of momentum. In Baez’s words, “this is about as plausible as powering a spaceship by having the crew push on it from the inside.” Shawyer argued that he was exploiting a loophole within general relativity. Baez calls his explanation “mumbo jumbo.”

Everything in science is open to questioning, of course, but nobody is going to throw out all the textbooks on the say-so of a single inventor trying to raise money for his company, SPR Ltd. Conservation of momentum is one of the most fundamental and thoroughly confirmed principles in physics. The EmDrive therefore got little notice outside of the “weird science” web sites. Last year, a Chinese group reported success with a similar device, prompting another blip of fringe coverage but little more.

Then Guido Fetta (a self-described “sales and marketing executive with more than 20 years of experience in the chemical, pharmaceutical and food ingredient industries”) built a third version of the EmDrive, renamed the Cannae Drive. Fetta convinced a sympathetic group of researchers at the Eagleworks Laboratories, part of NASA’s Johnson Space Center, to give it a test. The results were maybe, tentatively, a little bit encouraging. And that is when the nonexistent propellant really hit the fan.

A number of publications that should have known better threw caution to the wind. “Nasa validates ‘impossible’ space drive” was the headline in an online story by WiredUK. The author, David Hambling, declared that an engine like the EmDrive could “take astronauts to Mars in weeks rather than months,” and even managed to work in nationalistic hand-wringing about “another great British invention that someone else turned into a success.” Soon the madness crossed the pond; “Space Engine Breaks Laws of Physics,” declared Popular Mechanics. “EmDrive is an Engine That Breaks the Laws of Physics and Could Take Us to Mars,” summarized Mashable.

Put It to the Rocket-Science Test

Perhaps we should take a long cool drink at this point. Let’s start with the “NASA validates” part. NASA is a huge agency, with more than 18,000 employees. The testing was done by five NASA employees in a lab devoted to exploring unorthodox propulsion ideas. The team leader is a researcher named Harold “Sonny” White, himself a proponent of ideas about faster-than-light warp drives that most of his colleagues have classified as physically impossible. The lead author is one of White’s Eagleworks teammates, David A. Brady. Calling this group “NASA”—as almost every popular news story has done—is a gross oversimplification.

Still, science is science: What matters are data, not motivations or semantics. Did White et al actually validate Fetta’s version of the EmDrive? The abstract of their paper, which was presented at a propulsion conference in Cleveland, is freely available online. Reading it raises a number of red flags. The methodology description makes it unclear how much of the testing took place in a vacuum—essential for measuring a subtle thrust effect. The total amount of energy consumed seems to have been far more than the amount of measured thrust, meaning there was plenty of extra energy bouncing around that could have been a source of error.

Worst of all is this statement from the paper: “Thrust was observed on both test articles, even though one of the test articles was designed with the expectation that it would not produce thrust.” In other words, the Cannae Drive worked when it was set up correctly—but it worked just as well when it was intentionally disabled set up incorrectly. Somehow the NASA researchers report this as a validation, rather than invalidation, of the device.

Did I say that was worst of all? I may have  take that back. In the paper by White et al, they also write that the Cannae Drive “is producing a force that is not attributable to any classical electromagnetic phenomenon and therefore is potentially demonstrating an interaction with the quantum vacuum virtual plasma.” That last bit stopped me. What’s a quantum vacuum virtual plasma? I’d never heard the term, so I dropped a note to Sean Carroll, a Caltech physicist whose work dives deeply into speculative realms of cosmology and quantum theory.


Read the full article here.

17 comments on “Did NASA Validate an “Impossible” Space Drive? In a Word, No.

  • Ah, shucks! I was packed for Mars and destinations beyond!

    ” quantum vacuum virtual plasma ”

    I had never heard of that before either but I just checked it off to my physics ignorance. Next time I’ll call Brian Greene.

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  • Popular publications gratuitously misunderstanding a few tests and claims in a way that makes it sensational news? Perish the thought!

    Geez, no wonder the public has a poor understanding of science, given the way it’s treated in the media. Mainstream audiences deserve better than sensationalist “baloney”.

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  • There was also a recent claim by NASA to have discovered bacteria which used arsenic instead of phosphorus, another claim that failed to live up to scrutiny. NASA’s credibility is shot to pieces.

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  • A good alternative to the bull—- word, is the Australian polite version bulldust. Bull is said to be an Icelandic word meaning nothing or empty, presumably picked up from Icelanders by unsuccessful, English-speaking fishermen in the North Atlantic, when empty nets were dragged aboard. They must have attached the scatological expletive in order to add colour and vehemence.

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  • I’m I the only one who thinks the headline should read something like: “Glaswegian prankster wastes NASA’s time”? C’mon, he even named it the ‘cannae drive’!

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  • The critics are being unscientific here.

    NASA thought there might be an anomaly. They set up a set of experiments, and they found a repeatable testable anomaly. The same one seen by the Chinese, British and other US researchers.


    Rather than rubbishing it as impossible, how about looking into what’s going on. That’s how science advances, after all. Nobody is suggesting it violates conservation of momentum, just that there may be other effects we need to take into account.

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  • 9
    old-toy-boy says:

    Yes, the critics are being bit short sighted. Some of the greatest advances in scientific understanding were first observed at the very fringes of experimental results. The ones were no matter how often the experiment is repeated and modified the results are just not quite 100% or 0%.

    To give an example, Newtons laws of motion, when testing moving objects at high speed, the numbers never quite matched up. Which lead to Einstein’s relativity. Are we absolutely that Newton’s other law (Every action = reaction) is true in all cases? Lets face it, We know that relativity does not work at the microscopic scale.

    P.S. NASA have been know to get it occasionly wrong.

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  • Scientifically illiterate as I am, did not my secondary school physics teach that mass increases with velocity, becoming infinite a light speed? Or did I imagine that bit?
    So what happens to a drive that has mass but no limit to its fuel/ thrust, in a vacuum?

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  • NASA’s credibility is shot to pieces.

    Did you miss this part of the article: “The testing was done by five NASA employees in a lab devoted to exploring unorthodox propulsion ideas… Calling this group “NASA”—as almost every popular news story has done—is a gross oversimplification.”

    Just because some scientists at NASA make a mistake or do shoddy work doesn’t mean that “NASA’s credibility is shot to pieces.” Although I think you are completely wrong about the arsenic claim anyway. The claim for this drive violates conservation of momentum. If it was really true it would require a major rethinking of physics, even at the Newtonian level. The arsenic claim wasn’t at all the same kind of claim. It would have been a major discovery, life based on arsenic rather than carbon, but not something that would require rethinking any fundamental laws of biology.

    I also don’t agree that the arsenic claim was handled poorly by NASA. Or to be more precise the mistakes NASA made were essentially PR mistakes rather than science errors. I realize the claim turned out to be invalid but that hardly counts as a mark against anyone. If failure was grounds to label someone a bad scientist no one would escape such a label. The error with the arsenic finding was primarily around the way it got reported by the media, taking a preliminary result and announcing it as a major finding. From what I saw the actual NASA scientists were properly skeptical and tentative, they announced some preliminary results but they didn’t make grandiose claims, that was all just media hype added after the fact which for the most part NASA couldn’t control

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  • The problem is ,when journalism or who ever Trumps up a finding that realistically has little value. Even if this did work, what amount of thrust was made and how much is needed to make a spacecraft travel at even existing speeds? The news of this was titles like we were headed to Mars next week in a third of the time. Sensationalizing is what “journalism” seems to do best. The first article I read on this did just that and the comments that followed had us packing our bags as this author also wrote. The same can be said for warp speed. People talk like that is coming out next week using the basis that Star Trek had it in 1965. We are a gullible people and take the slightest hint of an idea as factual. No wonder 75% of the population reads 2000 year old books

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  • In way of what I would say is a regrettable necessity of putting forward a disclaimer, I am trained as a scientist. As a scientist, I am a product of a child’s inquisitive mind, moulded with discipline and experimental rigour in to a way of professionally viewing the universe in as impartial and objective manner as possible, all the while not forfeiting the human right of inspiration and awe at all that surrounds us. History has shown us, and this web forum often reflects through discussions on the subject of the human propensity for religiosity, that the scientific approach to discovery and understanding was hard won against the constant barrage of beliefs, traditions, superstitions and authoritarian orthodoxy. This is why I find it so disturbing that the tone of the discourse on the subject of whether there is any merit to EmDrive technology has, and still resembles the darkest ages of crowd-based refuting of claims which were concluded by the burning of heretics.
    I welcome any argument against the possibility of EmDrive technology, but not one that simply mirrors a ” constant barrage of beliefs, traditions, superstitions and authoritarian orthodoxy” that is held higher because it is called science. Science does not tell you what cannot be, it merely informs us as to what we currently believe we understand. To be a “scientist” is to confront the humbling reality that half we “know” is incomplete, while the other half we “know” is simply wrong.
    It is as simple as this; if there is a physical effect, it can be quantified (at least at the physical scales we encounter every day). If there is an effect that can be measured, and a system that can be manipulated, there is a chance to gain some understanding of underlying processes. To say a physical effect that can apparently be observed, quantified, and replicated cannot exist because it violates our long-held beliefs and understandings within physics, is the antithesis of scientific thought.

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  • to say a physical effect that can apparently be observed, quantified, and replicated cannot exist because it violates our long-held beliefs and understandings within physics, is the antithesis of scientific thought.

    No one is saying that. To start with the law of conservation of momentum is not a “long-held belief”. It’s not some dogma that people believe just because Newton said so and we always believe what Newton said. It’s a fundamental part of our basic Newtonian theoretical framework for understanding the physical world. If there were actual evidence that it was violated physicists would be tripping over each other trying to understand the reasons because there would probably be a Nobel prize waiting for whoever figured it out.

    All this article really comes down to is that it’s rational to be very skeptical of some claim that seems to refute something as fundamental as conservation of momentum. In actuality the fact that NASA DID bother to do a test of the mechanism shows that science worked the way it was supposed to here.

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  • It is fairly obvious that this author did not read the full text of the NASA results. If he HAD, he would have noticed that there where 3 test objects, not 2. The first two were slightly different designs for the thruster – one that was based upon the EmDrive, a second based upon the EmDrive but with slats cut into one of the surfaces, and a third that was a simple resistive load. The last object was obviously a NULL test case.

    The NASA testers found that both the EmDrive clones produced thrust, with slats, and without. So that closes some of the speculated theories as to how it works, including the original inventor’s. However, the resistive load was not observed to create any thrust – and IT was the control set.

    I will not speculate as to the overall plausibility of the violation of conservation of momentum. If quantum physics has taught us anything it is that sometimes quantum effects are weirder than we can imagine – but on the big macro stuff common sense usually holds sway. But it is clear that this critic is mis-reading (perhaps intentionally) the test results to discredit the experimental results.

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