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To a scientist, having an open mind is a virtue. However, scientists still get upset when they find a story in a "science" magazine which crowbars open the reader's mind so far that you can hear the brains sloosh out onto the floor. Here's how it works: if you say that you can move your car forward by bouncing a soccer ball back and forth inside it fifty thousand times, you'll get a quizzical look (at best). If you say the same thing but with "microwave photons" instead of soccer balls, you're reporting on cutting-edge science!
ACT THE FIRST
shnood: (roughly) an imposter; a person oblivious to just how trivial or wrong his ideas are."Were there any interesting speakers at the conference?"
"No, just a bunch of shnoods.""The magazine New Scientist loves to feature shnoods on the cover."
Note: someone who's utterly contemptible would not be a shnood, but rather a schmuck.
Scott Aaronson (27 May 2006)
Back in September 2006, New Scientist magazine published an article on the "EmDrive", a machine purportedly able to propel itself using microwaves bouncing inside a box. Those of us who remember the Dean drive and umpty-ump other wonder machines have no trouble recognizing this as the same old stuff: like all the wonder-powered spacedrives before it, it can only putter forward by violating the conservation of momentum.
When you want to go one way, you push something the other way: the total motion of all the pieces balances out to zero. This is the fundamental principle behind Newton's dictum that every action has its equal and opposite reaction, and it holds true not just in Newtonian physics, but in Einstein's relativity and the weird world of quantum mechanics.
New Scientist's reportage provoked science-fiction writer and physics buff Greg Egan to write an open letter saying he was "gobsmacked by the level of scientific illiteracy" the magazine showed.
So it goes, as they say on Tralfamadore. Claims of exotic spacedrives fuelled by violations of fundamental physics are, sadly but understandably, about twopence a dozen. The aspect of the affair which Egan found truly disturbing — indeed, reprehensible — was the way New Scientist glibly provided a "news" piece full of pseudoscientific gibberish purely to justify how the EmDrive might work. Their argument really pushed the limits of the absurd, too: Einstein's relativity has momentum conservation as a fundamental principle, so you can't use relativity jargon like "reference frames" to sidestep the conservation law. You can try to shout "Relativity!" like your own personal Expelliarmus incantation, but it will not persuade the Universe to comply.
Egan posted his letter to the moderated Usenet group sci.physics.research, and the physicist John Baez put a copy on the blog he co-hosts, The n-Category Café. This spurred enough people to write New Scientist that the magazine opened a blog thread to discuss the issue, opening with a self-exusing note from the editor, Jeremy Webb. (Said note, as far as I can tell, satisfied nobody.)
ACT THE SECOND
Discussion also continued simultaneously at the Café, eventually including Baez, Egan, the science writer Jennifer Ouellette and others. During this merry back-and-forth and round-about, lots of physics people spoke their minds, but naturally physics is only part of what New Scientist covers. In order to sample other viewpoints, I posted links to the relevant pages on a Pharyngula open thread. A commenter there, "Lab Cat", pointed out an article New Scientist ran last April about "Water: the quantum elixir".
So, off I trundled to Respectful Insolence, where this topic had just come up as "Your Friday Dose of Woo" (probably putting the idea in Lab Cat's mind). Then back to The n-Category Café to talk about it over virtual hot chocolate, and a little later Prof. Baez cross-posts a message to the Café and to the New Scientist blog.
Jeremy Webb wrote: We should have made more explicit where it apparently contravenes the laws of nature...Good, I'm glad we agree on that. But I hope it's clear: this article is not an isolated problem. It seems that New Scientist is moving to embrace flaky science, by reporting on it without letting ordinary scientists explain why it's baloney.
For example: your article on a faster-than-light drive designed using Heim theory, a run-of-the-mill crackpot theory that has never passed peer review in any reputable journal.
For example: your article about the chemical properties of water, which brings in homeopathy and "Masaru Emoto, who is said to have proved that water responds to the emotions of those around it". It mentions that most scientists regard this as ridiculous. But, it doesn't explain why. Maybe they're just old-fashioned?
For example: an article about how "Researchers around the world are opening their minds to the possibility that the phenomenon of anti-gravity is not just science fiction". It mentions that "Most respected physicists still scoff at the idea" — but it doesn't explain why. Maybe they're just too conservative?
The Shawyer article is just the latest in this pattern. You quote an engineer as saying the Emdrive is "a load of bloody rubbish" but you don't clearly explain why: it violates conservation of momentum! Instead, we get a cock-and-bull story about "changing reference frames", as if somehow relativity and "the strange nature of light" provided exceptions to this well-established law:
Hang on a minute, though. If the cavity is to move, it must be pushed by something. A rocket engine, for example, is propelled by hot exhaust gases pushing on the rear of the rocket. How can photons confined inside a cavity make the cavity move? This is where relativity and the strange nature of light come in. Since the microwave photons in the waveguide are travelling close to the speed of light, any attempt to resolve the forces they generate must take account of Einstein's special theory of relativity. This says that the microwaves move in their own frame of reference. In other words they move independently of the cavity — as if they are outside it. As a result, the microwaves themselves exert a push on the cavity.It's great fun to report on crackpots — done right, it can be highly educational. In fact, I can even recommend some more to you — I know a lot of them!
But surely you can afford some writers who don't make up their own wild new theories. And, surely you can get some reputable scientists to explain why the theories you're reporting on are generally considered nutty. No?
It's hard to separate all the different threads of wrong and fail in the passage quoted from New Scientist, so tightly are they woven together. For example, it's not clear why the photons inside the cavity are moving "near" the speed of light, not at it (maybe the EmDrive has to be filled with air to slow the photons down?). Most importantly, the business about microwave photons moving "in their own frame of reference" and what that supposedly implies is nonsense of the purest quality. You don't have to use a reference frame tied to a moving object to understand the motion of that object; that's like saying a bullet fired down the barrel of a gun is outside the barrel because it is moving. On top of that, you can't actually define an inertial reference frame for a particle travelling at light speed — think "cosmic divide by zero error" — but that's practically beside the point.
(As Baez very justly points out, New Scientist pulled a fast one when they titled their pet thread "Emdrive on Trial" and not "New Scientist on Trial", which is what really concerned the first people to speak up. Again, spacedrives which don't go are too common to count; it's the magazine's editorial policy we care about. And yes, Virginia, it's not just physicists who care. By the way, all the links in the above quotation are from the original.)
ACT THE THIRD
So, what have we got so far? A bad idea, scion of a lineage of bad ideas, gets a little publicity; scientists get upset; and the people who generated the publicity try to cover their newly fact-checked asses (but because they're not going to take an injury to the pocketbook because of this, they don't have to do very much at all). There, the matter rests. . . just waiting for somebody new to come along and pump in a fresh dose of hot air, inflating the sorry mess into a genuine manufactroversy.
Enter Wired magazine.
On their "Danger Room" blog, David Hambling adds a note of paranoia to the whine about oppressive scientific orthodoxy: Red China is building a Device! We are told that Shawyer himself has received word that his work has been confirmed:
"NPU [Northwestern Polytechnical University in Xi'an] started their research program in June 2007, under the supervision of Professor Yang Juan. They have independently developed a mathematical simulation which shows unequivocally that a net force can be produced from a simple resonant tapered cavity," Shawyer tells Danger Room. "The thrust levels predicted by this simulation are similar to those resulting from the SPR design software, and the SPR test results."What's more, Shawyer says, NPU is "currently manufacturing" a "thruster" based on this theoretical work.
Fear the spaceborne legions of Fu Manchu.
The NPU have confirmed that they have reproduced the theoretical work, and are building a demosntration [sic] version of the Emdrive.
Colour me. . . doubtful.
Greg Egan, who pointed me to this story, has an important observation to make about it:
But somehow their courageous blogger couldn't summon the presence of mind to ask Mr Shawyer or his Chinese colleague Professor Yang the burning question: "We switch on the Em-drive. We switch it off. Our spacecraft is now moving, and no microwaves have been emitted as exhaust. So momentum is conserved ... how?"
EPILOGUE
People tend to get upset when physicists debunk a proposal for something glamorous like easy space travel. I can sympathize: who wouldn't want a personal interplanetary spacecraft, or the chance to spend summer vacation on Mars? What business have those egghead scientists of puncturing our dreams about exploring the stars? But, consider the flipside: how do we know that the stars are places to be explored, instead of just little twinkling lights poking through an upside-down metal bowl, set over the flat Earth?
We know that the stars are distant suns with planets of their own in orbit around their nuclear fires because we do science. It is science which lets us know that the stars are targets of discovery and exploration. The knowledge that they are light-years away, and that the EmDrive will not help us reach them, is the price we pay for knowing their value.
Portions of this post were extracted and edited from this page of my old website.
Physical Science
Technology
Comments
Thanks for the background. Got a few emails about the Em Drive but wasn't familiar with the history behind it . . . is this going in the Will Not Die Bin with the water-powered car?
Posted by: Rebecca Watson | September 25, 2008 4:53 PM
Sadly, it might — it's got legs. That whole "we can travel through space for cheap" business makes for a tenacious meme. Some kinds of crankery have more of a niche appeal — rabid anti-Semites can go for "Einstein was wrong" crackpot schemes, for example — but if you're peddling a spaceship or a cancer cure, people will line up.
Posted by: Blake Stacey | September 25, 2008 5:02 PM
This whole thing seems to show that the way "Conservation Laws", at least for energy, momentum and angular momentum, are being taught isn't convincing. Maybe the Noether theorem should be used - the fact that physical laws are unchanging when you move through space implies momentum conservation, through time, implies energy conservation and during rotation implies angular momentum conservation. Could that possibly help a lightbulb go on in a few brains?
Then we could talk about how such a device must be implying some change in the rules of physics between here, and everywhere else... What changes would those actually be and what effects? When I think of how underlying these rules are in how everything works when someone blithely says they aren't applicable, the fact that the whole world we see would be different isn't recognized.
Posted by: Markk | September 25, 2008 5:54 PM
Hmmm, I should try a post or two on Noether's Theorem, just to see how it goes.
Posted by: Blake Stacey | September 25, 2008 6:59 PM
Could that possibly help a lightbulb go on in a few brains?
Noether would be great for people who are genuinely interested in the physics. But the biggest problem here is that there are people (including journalists) who simply don't want to understand the physics; they'd much rather be bamboozled by Shawyer-babble about photons "having their own reference frame" than accept that their own everyday intuition (which John Baez captured in the "move your car with soccer balls" analogy) is actually already spot on.
The killer is, Shawyer himself insists that his claims do not violate any conservation laws. OK, it's nice that he wants those laws to continue to apply, and it lowers his crackpot index a little ... but it allows him to camouflage his nonsense more easily when talking to journalists who have no real feel for things like the momentum in an electromagnetic standing wave. As long as the drive is actually switched on, the average layperson is just going to nod their head and defer to all the gobbledygook that hides Shawyer's false momentum accounting.
So I keep asking his supporters this question until I'm blue in the face: "If Shawyer is right, and his drive doesn't violate conservation of momentum, explain the following scenario. We switch on the Em-drive, it accelerates our spacecraft, then we switch it off and our spacecraft is still moving. There were no microwaves around initially, and there are no microwaves around now -- they've all been absorbed into the cavity walls, just leaving the spacecraft a little bit warmer. The spacecraft has gained momentum. How is momentum conserved?"
At which point, they change the subject and say things like "Well, he measured a force in his workshop, which trumps all this theoretical nit-picking!"
Posted by: Greg Egan | September 25, 2008 7:24 PM
I almost think he deserves some special kind of meta-points for that manoeuvre.
Or else the machine sprang a leak. . . .
Posted by: Blake Stacey | September 25, 2008 7:29 PM
Em-Drive : A technology that's just not going anywhere ...
Posted by: llewelly | September 25, 2008 8:38 PM
Thought experiment--
If it were true that an Em-drive could work, then ordinary light, which is moving all over the place at the speed of light, would be knocking our satellites out of orbit every time the sun rose, yes? ;)
Posted by: The Perky Skeptic | September 25, 2008 9:04 PM
Perky Skeptic, maybe I'm missing the joke, but this sounds like you're trying to cast doubt on the idea that light can exert pressure. But of course it can exert pressure, and there's no reason why a "photonic rocket", which emits some form of electromagnetic radiation, wouldn't work. The only flaw with the EmDrive idea is the claim that it can accelerate without anything at all leaving the device, microwaves included. If Shawyer cut a big hole in it, it would accelerate in space. But not very fast; there's a limit of 3.33 micronewtons per kilowatt for that process -- a limit that Shawyer claims to break, which is what gives his fantasy a hypothetical edge over real technology.
Posted by: Greg Egan | September 25, 2008 10:26 PM
I am not the least surprised that the world of science has at its fringes gullible idiots like Jeremy Webb and his ilk. After all look at how many humans have been duped by religion, all religions, into murder, torture, and assorted mayhem all in the name of "their god". Oh, and don’t forget controversy, any kind of controversy, sells magazines too.
Posted by: Ron Hager | September 25, 2008 10:55 PM
I'm not sure gullible idiots is the right description to apply to all the guilty parties. I mean, I don't know if they take homeopathic "medicine" or check their daily horoscopes. . . a person can be fairly level-headed in their workaday routine and still enable the spread of pseudoscience. "Fundamentally misplaced priorities" springs to mind as a possible description; "out to make a buck" is another.
Posted by: Blake Stacey | September 26, 2008 1:00 AM
a person can be fairly level-headed in their workaday routine and still enable the spread of pseudoscience
Indeed, New Scientist editorials are generally notable for their level-headedness, and the magazine is usually pretty strongly pro-rational, especially on issues with some political currency, such as stem cells, climate change and immunisation panics. But about 30% of its physics articles are "What's the most outlandish thing we've found on the arXiv this week?", and every year or so they find a way to string together six implausible things and announce the resulting concoction as the first testable blueprint for time travel.
Posted by: Greg Egan | September 26, 2008 1:37 AM
Re: the April paper about the quantum effects of water that mentions Masaru Emoto. Are you sure it's not an April Fool's joke? Sounds like quoting Dr. Emilio Lizardo on the subject of herpetology.
- John Parker
P.S. Actually, John Parker was my great grandfather. He didn't live in Grover's Mill, NJ though.
Posted by: Buzz Parsec | September 26, 2008 3:29 AM
Great post. I just yesterday wrote a letter to NewScientist commenting on an editorial that said "Physicists should seize on every chance to publicise their work." I wonder whether it ever occurs to them (not necessarily NewScientist specifically) that nonsensical 'science' reporting harms science. People will lose trust in what the alleged scientists say and do, if that isn't already the case. I'm all for getting science closer to the public, but science journalism comes (as all kind of journalism) with a large responsibility.
Anyway, something completely different: about the anti-gravitation. Can somebody please tell me what the objections are to anti-gravitation. Not to this spinning semi-conductor experiment they are reporting about, but just generally theoretically. Best,
B.
Posted by: Bee | September 26, 2008 4:37 AM
If it were true that an Em-drive could work, then ordinary light, which is moving all over the place at the speed of light, would be knocking our satellites out of orbit every time the sun rose, yes? ;)
YORP effect. It doesn't knock them out of orbit, because gravity is stronger than the photon scattering effects.
And I've got a few billion atoms being held hostage in my lab by radiation pressure. They would assure you it's very real, if they could.
Posted by: Tom | September 26, 2008 6:50 AM
I don't think a story published in the 8 April issue of a weekly magazine gets to be excused as an April Fool's item.
Posted by: Blake Stacey | September 26, 2008 11:45 AM
Yeek! I should have thought through my thought experiment a little more thoroughly, looks like! Thanks for the corrections.
Posted by: The Perky Skeptic | September 26, 2008 3:06 PM
And now Universe Today went on to perpetuate the stupidity.
Count me in for wanted to hear more about Noether.
Posted by: Sili | October 19, 2008 11:44 AM
How's it intended to work, just out of curiosity?
I take it it's something along the lines of "waves have shorter wavelengths at small end and therefore higher momentum than at large end?"
Posted by: andy.s | October 28, 2008 6:03 PM
It's something like that, although I for one find it hard to extract anything from their verbiage which makes even that much sense.
Posted by: Blake Stacey | October 28, 2008 8:57 PM
What does Lorentz Force have to do with this machine? In his paper, he uses a shortened version for the force which neglects the cross-product between velocity and the magnetic field. In Shawyer's formulation the force is just placed there without regard for the direction.
Also how is it that lambda two is greater than lambda one?
Posted by: Martin C. Baker | December 22, 2008 12:01 AM
So, just what would be the result be if EM drive did work are we looking at all physicists resigning due to lack of knowledge and understanding of this proposed device?
It seems a very simple device, has no physicist tried building one to prove this as a fraud. Don?t get me wrong I am very sceptical about this, but if experimental results disprove theory then both need to be investigated by all parties that have an interest?
Posted by: Mike | January 7, 2009 8:59 AM
There comes a point when a proposal is so extreme that it is no longer necessary to test it by experiment. One does not need to test firsthand the hypothesis that one can swim the backstroke to Alpha Centauri.
Posted by: Blake Stacey | January 7, 2009 10:22 AM
>There comes a point when a proposal is so extreme that it >is no longer necessary to test it by experiment.
Yes I think you have hit the nail on the head. Did you know someone has proposed that the earth is round and not flat! Couldn’t possibly investigate it as it is such a stupid idea!
Just because something is extreme does not mean it should not be investigated. I remember similar comments when two Australian scientist proposed that bacteria caused stomach ulcers. The question is can you prove it does not work? I can not prove it works or that it does not, but I am keeping an open mind. Surely the correct position for anyone seeking the truth.
Posted by: mike | January 8, 2009 6:30 PM
The evidence that the EmDrive will not and cannot work is all the evidence which supports our understanding of mechanics and electromagnetism. Working on your computer? Using WiFi? Talking on a cell phone? Ever, in your life, listened to the radio or watched television?
Your analogy is backwards. Shawyer is insisting, although he doesn't recognize it, that the Earth may be flat after all.
One does not make progress towards truth by being blankly receptive to each and every new idea one hears on the bus or reads on the Internet. Instead, one has to examine the new idea and see how it fits with the facts known so far.
Posted by: Blake Stacey | January 9, 2009 10:46 AM
I have a SERIOUS question whether it sounds like one or not. Is the "impossibility" (which I hope is an acceptable descriptive word even though I don't speak "science" very well) of the "Em-drive" any more or less "obvious" to scientists than the non-existence of God? Various articles I have read state that surveys of scientists over the past decade indicate that roughly 93% of them do not believe in God. I accept and think I understand those 93%. What is YOUR explanation for the remaining 7%? Are they lying (possibly to themselves as well as others) in hopes of winning the Templeton Prize? Have they been brainwashed? OR is their room for a twenty-first century bona fide scientist who accepts evolution and everything else science is teaching us to believe in the Judeo-Christian/Muslim God, as mysterious and nebulous as "He" appears to be? I would genuinely appreciate as serious a response as you can muster from any of the previous commenters or any other practicing scientist. I have personally concluded that science and belief in God are incompatible. What say you?
Posted by: Jack Kolinski | January 25, 2009 10:47 PM
I would not say this is a complete explanation, but I'd wager that part of the issue is that it's easier to reconcile the "faith of one's fathers" with part of our current scientific body of knowledge than with the entire thing. If your workaday duties as a scientist only require you to deal with, say, molecular biology, then you might be all that familiar with the open questions of cosmology or cognitive science, and consequently, you might succumb to seeing the fingerprints of your favourite deity in those fields. (Empirically speaking, it's easy to find a biologist who is a self-identified Christian and also fully accepts evolution. However, it's harder to imagine that somebody who's actually made a formal study of quantum mechanics would say the stuff Ken Miller says about it, and similar accusations have been levelled at Francis Collins.)
"Judeo-Christian" is also a horribly deceptive term, in this context (and in many others). Yes, Christianity arose out of Judaism, but look at their history together since — talking about a "Judeo-Christian tradition" is like talking about the "Capitalist-Marxist tradition". Followers of Reconstructionist Judaism consider themselves fully religious but may hold the view that, for example, any god whose existence is detectable by evidence in the physical world is a diminished god. (They're not exactly unified on these questions, but that's one position I've heard.)
To the perennial question "Are science and religion compatible?" I can best answer only "Mu". The story that they are ceaselessly at each other's throats is an oversimplification, but, I think, it carries slightly more truth than the opposite oversimplification, that everything is hunky-dory.
The question of whether the EmDrive could ever possibly work is, by contrast, a question which pertains to a single field of science — physics.
Posted by: Blake Stacey | January 26, 2009 9:11 AM
Hmmmm,
So someone has independently verified that this device doesn't provide movement then? As someone independently verified that china is building one?
Regardless of the physics, all I really want to know is if I give this device power will it move? I don't care how it does it only that it moves to the extent that it has been claim...?
Posted by: Jon | February 24, 2009 5:27 AM
That's like saying, "Regardless of medicine, will I die if somebody rips out my heart?" It is not a judgement in which the relevant field of learning should be neglected.
I've never heard of the Chinese announcing any results on whatever device they've supposedly built. It seems to have dropped off the radar, as it were. Since it's not going to work, whatever movement they might get would be a result of the device springing a leak and nudging it a little sideways or the like. If they see nothing at all, or if everything they see they recognize as due to experimental error, then they might well shove the plans in a desk drawer and try to forget they ever got involved.
(Experiments which find nothing at all tend to get talked about somewhat less than those which demonstrate a clear effect. It's the "You say nothing happened? So what?" syndrome.)
Posted by: Blake Stacey
| February 24, 2009 11:45 AM
ok there are two parts to this.
did anyone notice that the UK gov appointed an independant investigator who reported that it worked?
and that no one has bothered to repeat the experiment?
oh except for those silly chinese.... did anyone wonder who Professor Yang-Juan is?
just about everyone else has said is that its my bat my ball you have to play by my rules... arrogance previously shown for several years after the wright bros were flying... the humble bumble bee that didn't know it could not fly, untill people changed the rules
Science advances by changing the rules! ... establishing new rules, modfication of old rules or just tossing the old. Ridgid dogma is not science. Science and so called laws are based on observations of real life events that can be repeated not blind faith in laws...
Yang-Juan's team expectations... "A Flight thruster development programme has started, with delivery of the first thruster scheduled for August 2009."
so lets just see shall we
Posted by: Andrew | March 19, 2009 6:10 AM
I'm not sure how to say this kindly, but it's pretty clear that you don't have a friggen idea how science works.
"Observations of real life events that can be repeated". . . like the observations which established the conservation of energy, the conservation of momentum, the Maxwell Equations. . . .
"I'll have demonstrated an entirely new form of energy production by the end of 2000." So said Randell Mills, crackpot advocate of "hydrino" energy, in 1999.
We've been down this road before.
Posted by: Blake Stacey
| March 19, 2009 9:19 AM
More simply, Andrew has been confused by an oversimplified, pithy saying. A more nuanced gloss would read something like:
If a bumblebee's flight were to be described by the known laws of aerodynamics and biomechanics, it would be impossible. However, the bumblebee clearly does fly, and so there must be some aspects of these fields we don't fully understand yet.
See, it's not that science purports to describe the real world accurately. Science builds models of the real world that match it in certain ways, and uses those models to predict real-world phenomena. The example of the bumblebee is a parable, reminding us that -- McLuhanism aside -- the model is not the world. However, just because there are some phenomena we don't completely understand yet doesn't mean that a refinement of the model cannot capture them. And, indeed, we now have a solid description of how, exactly, a bumblebee manages to fly.
Posted by: John Armstrong | March 19, 2009 12:10 PM
The story of how that saying came to be is rather interesting. It started in the early 1930s with an engineer doing a "back of the napkin" calculation starting from unwarranted assumptions; the result of this less-than-realistic calculation was then tarted up and spread far and wide.
Plus ça change. . .
Posted by: Blake Stacey
| March 19, 2009 12:49 PM
I will believe the em-drive works when it is proven it can propel itself in space. When is such an experiment going to take place? I am waiting to see if it works. If it does not work I have devised an alternative mechanical method of reactionless propulsion I plan to build. Obviously a solid state electronic device with no moving parts would be preferable and less likely to break on long space trips, but it does sound a bit too good to be true.
Posted by: Trevor Loughlin | November 7, 2009 9:28 AM
When its inventor finds the right idiot with enough money to overlook (a) a track record of failure and (b) the entirety of physical science.
Good luck with that.
It's not about what would be convenient, it's about what is physically possible in this Universe.
Posted by: Blake Stacey
| November 7, 2009 1:21 PM