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Undoubtedly, many people of theinventive type can relate to this experi-ence—thinking up a seemingly in-genious idea for making a system thatgenerates persistent motion with no en-ergy source. Recorded propositions forbuilding similar contraptions, usuallycalled perpetual motion devices1 or per-petuum mobile (PM for short), date backto at least the seventh century CE (Peter2004). A plethora of mechanisms basedon such ideas have been designed andbuilt, ranging from the stunningly trivialto the ridiculously complex. Differentthough they may be, all share one com-mon quality: much like my “magneticcan,” they do not work.

Only in the nineteenth century werethe culprits behind this perpetual failure(pun intended) discovered. These are therelentless laws of physics, or more specif-ically, the first and second laws of ther-modynamics. One would expect thatever since these laws were established(with solid theoretical and overwhelm-ing experimental basis), PMs wouldhave become history. Surprisingly, that

hasn’t happened. In fact, even at the be-ginning of the twenty-first century, thePM “industry” isn’t just alive and wellbut, arguably, more popular than ever be-fore. And it’s not just the “modern” kindsof PMs, like “zero-point modules”2 or“torsion field generators,”3 but the mostclassical ones too—the “overunity de-vices,”4 which violate the first law ofthermodynamics. In fact, at http://tinyurl.com/magnetPM you can see a grownman playing with magnets in almost thesame way I did as a child. This is just oneexample, but many more exist. Theforum at www.overunity.com alone listsmore than 25,000 members (as of De-cember 2010), most of whom describethemselves as overunity inventors, andYouTube contains hundreds, if not thou-sands, of videos showing supposedlyworking PMs of all kinds. And thenumbers keep growing.

Of course, such a high interest inPMs is easily understandable. In lightof the global energy crisis, pollution,and human-induced climate change, aninventor of a free and clean energy

source would certainly become rich andfamous beyond imagination. On theother hand, centuries of utter failureand PMs’ scientifically proven impossi-bility should serve as an overwhelmingdemotivator. So, how can all these peo-ple still believe in PMs—and not justbelieve but waste a lot of time and ef-fort in trying to build such machines?

There are several possible explana-tions. As the famous case of John Keelysuggests (“Keely’s Secret” 1899), someof the “inventors” of PMs might well befrauds who are looking for an overlynaive investor or just seeking publicity.Others are simply ignorant about theabovementioned impediments, espe-cially at first. But, judging from variousforum discussions, the majority appearto be honest and knowledgeable in thisparticular field. These people sustaintheir beliefs in the manner typical ofmost pseudoscientists—by denying thevalidity of scientific laws (Choronzon1991) and by postulating a grand con-spiracy theory, which might explain allthe seeming failures. According to thistheory, working PMs are not only pos-sible, but they have already been builtand the truth has been suppressed forvarious reasons and by various means,ranging from hostile discouragement tophysical elimination of the inventionalong with its inventor (Bearden 2009).

Of course, thorough arguments havebeen mounted against conspiracy theo-ries in general and this one in particular(Volkay 2007). But overall, a good skep-tic should rely on testable facts ratherthan abstract arguments as much as pos-sible, no matter how well reasoned thesearguments are. Fortunately, testing con-spiracy theories—at least this particularone—isn’t difficult (albeit potentially

The Perpetual QuestHow to make a perpetual motion device and live to tell about it.

DIMITRY ROTSTEIN

Once upon a time, at the tender age of ten, I wasplaying with a magnet and an empty tin can. Sud-denly I noticed that if I moved the magnet away

from the can, with the distance between them remainingthe same, the can rolled faster and faster in its pursuit ofthe magnet. But what if the can was rigged to the magnet,I thought? Obviously, the device would continue acceler-ating, without the aid of any outside force, at least until ithit the nearest wall. Three pencils and some duct tape wereenough to constrain the magnet in front of the can at thedesired distance. But to my great dismay, the resulting sys-tem remained completely motionless.

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lethal if the conspiracy theorists are cor-rect), and I have done exactly that ontwo separate occasions.

The first opportunity came along inNovember 2007, during an annualtechnological competition called Biz -Tec. Competitors had to submit a de-scription of some novel invention oftheir own to be judged by a panel com-posed of industrialists, venture capital-ists, and academic staff. The best proposals in terms of practicability, in - novation, and commercialization wouldget a cash prize, but I was only inter-ested in the judges’ reaction to my pro-posal. According to the contest rules,every submitted idea—no matter howsilly—would receive thorough feed-back. For my submission I selected oneof my own designs, which I had comeup with awhile back. At the time of itsconception, I even believed it was avalid idea for a short while before I re-alized it was just another PM. (It’s sohard to criticize your own ideas.)

The idea is pretty straightforward.Imagine a simple saucer lying on atable. Both sides of the saucer are sub-jected to a constant and equal air pres-sure, so it doesn’t move. But the airpressure is caused by the air moleculesrandomly bouncing off the saucer’s sur-faces. Now, suppose that the saucer’slower surface was shaped (on a micro-scopic level) in such a way as to reflectthe air molecules in some specific direc-tion rather than randomly. Then, the air

pressure on this surface might be dif-ferent from normal. Even if the pres-sure changed only by one percent, theresulting difference would be enough tolift the saucer itself, as well as a two-pound weight attached to it, off thetable. Of course, this principle isn’tnew—it’s just an unusual variation ofan old PM concept known as Maxwell’sdemon, except that my PM doesn’thave any moving parts. Richard Feyn-man showed that Maxwell’s demoncannot work (Feynman et al. 1963), buthis proof applies only to the movingtrapdoors of the PM. So my design,having no moving parts, does appear tohave a fighting chance of working; pro-vided, of course, that we throw away thesecond law of thermodynamics, whichexplicitly forbids energy extractionfrom a static pressure.

According to the conspiracy folks,the judges at the competition, after see-ing my proposal, had to make sure thatI wouldn’t build such a device. At best,they’d just laugh at my idea until I gaveup and threw it away in frustration. Atworst, they’d call the Men in Black toerase my memory or even my very ex-istence. Needless to say, I’d prefer thefirst option. But their actual responsewas something I wasn’t expecting at all:of some 150 submissions, ten receiveda $1,000 prize, my “flying saucer” beingamong those ten! The promised feed-back was also quite encouraging. In allfairness, some judges did express their

doubts that such a device could work,but they all liked the idea.

My experience is far from unique.Just a few months after the BizTeccompetition, designer Clay Moultonmade headlines after winning a similarcompetition with his “gravity lamp”concept: a 600- to 800-lumen lightsource powered for a period of fourhours by a slowly descending 50- to100-pound weight (Moulton 2008).Simple high-school-level calculationsshow that these requirements corre-spond to the device having an efficiencyof far beyond one hundred percent.

My second opportunity to test theconspiracy theory hypothesis came alonga year after the BizTec competition. Aspart of my graduate training, I had to de-sign and implement a laboratory experi-ment. Even though I came up with a fewother interesting ideas, I decided to pres-ent my “flying saucer” first, again just totest the reaction of the professor incharge of the lab (hopefully not the“morph into an alien and devour me”kind of reaction). I was in for anothersurprise. Professor Yakov Krasik, the pro-fessor in charge, became excited aboutthe idea and decided to go forward withit. Being a seasoned physicist, he ofcourse recognized a PM at once, but thatdidn’t seem to bother him. So we startedbuilding our “flying saucer.”

Due to financial constraints, wecouldn’t reshape the surface on a micro-scopic level, so instead we made a macro-scopic array of conic holes to concentratethe reflecting air molecules. Com putersimulations showed that this shouldwork,5 provided that the air moleculesdidn’t collide with each other while insidethe holes (which would randomize theirtrajectories, destroying the alleged con-centrating effect). To meet this condition,we put the whole contraption into a vac-uum chamber and reduced the air pres-sure until the mean free path6 of the airmolecules became larger than the size ofthe holes (at about 10,000 times less thanthe normal air pressure). According tosimulations, even under such low pres-sure the lifting force would be strongenough to be detected by high-precisionscales. The experimental setting is shownin figures 1 and 2.

It should be noted that I only ranthe experiment after I personally tested

Figure 1. The “flying saucer”—or rather a plate (holes up).

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the equipment to make sure that nei-ther High Cabal nor Illuminati agentshad messed with it. Naturally, there wasno measurable difference in the plate’sweight—with the holes facing up ordown—at any pressure. Of course, if theresults had been positive, then the sec-ond law of thermodynamics would flyout of the window faster than any fly-ing saucer. Science prevailed once againwhen the saucer failed to work.

However, to my great surprise, Pro -fessor Krasik was genuinely disap-pointed by the negative result. I askedhim whether he really believed this ex-periment could possibly have worked.After all, I told him right from the startthat it couldn’t, and I thought we wereon the same page. This was his re-sponse: “I was almost sure that nothing[would] be positive, but … life is [a]complicated thing—and the more I’mworking, the more I understand thatnot all what I know, or what I studied,is correct” (ellipsis in the original). Now,dear reader, I ask you this: does that re-ally sound to you like someone who istrying to suppress anything? To me itsurely doesn’t.

No, I can definitely say that I havefound no attempt at conspiracy. So, ifno one has been able to build a workingPM over the centuries, then perhapsthe devices are indeed useless. Well,maybe useless isn’t the proper word here.After all, a PM has already earned me(despite myself ) a thousand dollars,some lab experience, and this journalpublication. But do PMs really work orcould they even possibly work? There’snot much chance of that, I’m afraid.

Some may point out that a few iso-lated examples don’t constitute a thor-ough study, and they’d be right. How-ever, it takes only one whistleblower toexpose a conspiracy (if it exists) andonly one small hole in the wall of pigheadedness to push a radical ideathrough (if it’s valid). I have discoveredtwo such holes in the first two placesthat happened to come along. Not evenonce have I encountered any hostilityor ridicule of the kind that PM propo-nents claim to suffer. If anything, myexperience shows that the academy andthe industry are more lenient towardPMs than they should be. This obser-

vation probably doesn’t apply to mostscientists and engineers, but the level ofacceptance for PMs that I’ve witnessedis still surprising—if not troubling. Asfor the more extreme conspiratorialideas, there is the undeniable fact thatas I write these lines, I’m still very muchalive. Notes

1. The term perpetual motion device is actuallya misnomer because the existence of perpetualmotion is assured by Newton’s first law. A moreproper name would be perpetual motor (still ab-breviated PM), because the idea is to generateuseful work from the perpetual motion, whereasthe real perpetually moving object is useless inthis respect. If you try to produce work from itsmotion, it will cease to move as soon as its initialkinetic energy is depleted.

2. The zero-point module (ZPM) is a hypo-thetical device that can utilize vacuum energy.According to quantum field theory, each point inspace contains an enormous, perhaps even infi-nite, amount of energy. However, there is no sci-entifically plausible way to harness this energy, atleast not without violating the existing laws ofphysics. Although some PM inventors claim tohave constructed devices that use vacuum energy,the whole ZPM concept is regarded as pseudo-science or, at best, science fiction.

3. Torsion field theory, originally put forwardby a few Soviet scientists, postulates an existenceof fields unknown to science with amazing prop-erties, among which is the ability to produce un-limited energy, antigravity, and faster-than-lighttravel. The theory (and resulting devices) is gen-erally considered to be pure nonsense.

4. An overunity device is any system that pro-duces more useful energy than it consumes. Intechnical terms, this means that its energy effi-ciency is greater than one or unity (i.e., more than100 percent), hence the name “overunity.” Suchdevices would obviously violate the law of energyconservation (the first law of thermodynamics)and thus are scientifically impossible.

5. It was discovered later that one of the for-mulas for the simulation was missing a sine factor,

which explains the false-positive result. Of courseit was obvious from the start (at least to me) thata simulation that produces nonphysical resultsmust be flawed.

6. The mean free path is the average distancethat an air molecule traverses before hitting an-other molecule. At normal air pressure, it’s lessthan one-tenth of a micron. Reduced air pressuremeans fewer molecules flying around, hence theincrease in the mean free path.

References Bearden, Tom. 2009. Suppression of the MEG.

Public correspondence, February 11. Avail -able online at www.cheniere.org/correspon-dence/021109.htm.

Choronzon, Frater. 1991. Perpetuum mobile: Anassessment of the ‘laws of thermodynamics’ froma Gödelian viewpoint. Available online athttp://freespace.virgin.net/ecliptica.ww/book/perpetuum.htm.

Feynman, Richard, Robert Leighton, and Mat -thew Sands. 1963. Ratchet and prawl. In TheFeynman Lectures on Physics. Reading, MA:Addison-Wesley.

Keely’s secret disclosed. 1899. The New YorkTimes ( January 20). Available online athttp://tinyurl.com/nyt-keely.

Moulton, Clay. 2008. Gravia. Greener GadgetsDesign Competition 2008. Available onlineat www.core77.com/competitions/greener-gadgets/projects/4306/.

Peter, Hans. 2004. Perpetuum mobile: Concepts I.Available online at www.hp-gramatke.net/perpetuum/english/page0020.htm.

Volkay, Chris. 2007. Is this article on conspiraciespart of a conspiracy? SKEPTICAL INQUIRER31(5) (September/October): 44–46.

Figure 2. Vacuum chamber with the test “saucer” on the scales.

Dimitry Rotstein, a grad-uate physics student atthe Israel Institute ofTechnology, has had alifelong interest in inven-tions and entrepreneur-ship. This is his secondcontribution to the SKEPTI-CAL INQUIRER.

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