Forgot your password?
typodupeerror
Science

NASA Still Trying to Verify Anti-Gravity Claims 430

Posted by michael
from the wild-blue-yonder dept.
uncoda writes "The L.A. Times has an article about NASA research into a phenomenon in which the effect of gravity is supposedly reduced. It sounds like cold fusion or polywater to me, but who knows?" We've posted two previous stories about Podkletnov's research: one from a couple of years ago and another more recently.
This discussion has been archived. No new comments can be posted.

NASA Still Trying to Verify Anti-Gravity Claims

Comments Filter:
  • by AlaskanUnderachiever (561294) on Monday March 25, 2002 @02:32AM (#3219515) Homepage
    Think about the potential this has for revolutionizing small part manufacturing. The precision that was till now only achieved in a LEO or better could be accomplished right here in EveryTown, USA. Well, probably not based on what I read in the article. But it's one of the few practical applications that I could think of (small scale, limited effect). That is assuming this doesn't turn out to be another "Free Energy" type hoax.
  • i swear to god that cat's must have these things in them.

    which brings up a point in itself, the age old open-faced peanut butter sandwhich on the back of a cat argument.
    • by Anonymous Coward
      On a note related to your cat-sandiwch complex: As kids, we wanted to see what would happen if you placed a slinky on an escalator. We reckoned that the slinky would fall forever, if it fell in synch with the escalator. One day we tried it out. We went to the mall, slinky in hand, and we dropped the slinky on the escalator and retreated to watch from the floor above. Our slinky stopped working a few seconds later and before we could reach it, got caught in the top of the escalator.
  • by Ian Lance Taylor (18693) <ian@airs.com> on Monday March 25, 2002 @02:39AM (#3219550) Homepage
    Wired [wired.com] had a good article [wired.com] about this guy a couple of years back.
  • by adminispheroid (554101) on Monday March 25, 2002 @02:42AM (#3219564)
    This has been going on for a while. See the most recent note [aps.org] on this subject from Bob Park's "What's New." He refers to an earlier $2M that got dropped on this crackpottery.
    • So what you're saying is that NASA have spent $2.6M trying to disprove this "crackpottery" and haven't yet managed to do it?
      • by Rogerborg (306625) on Monday March 25, 2002 @08:13AM (#3220376) Homepage
        • what you're saying is that NASA have spent $2.6M trying to disprove this "crackpottery" and haven't yet managed to do it

        This is what passes for insightful around here? In case you slept through Science 101, the onus is on the discoverer to provide proof in the form of a repeatable experiment. As this has never happened, there's nothing there to disprove. $2.6 million is pocket lint to NASA, this is just someone scraping together the spare change from other projects, not a serious attempt to prove or disprove anything.

      • What NASA is doing is somewhat along the lines of insurance. Who here actually expects to have their house burned down, or to get squashed in a plane crash??? Nontheless we pay a small pittance in the hopes that if something like that doeshappen, we'll get money to cover the extraordinary expenses.

        In this case, the money spent on this project is rather small, in a NASA budget expense -- but even with a 2% chance of partial success, the amortized savings as a result of even a pointer in the right direction are enough to make the fool's rush more than worth it.

        As was vaguely aluded to in the article, the possible PR cost to NASA's credibility was probably more of an impediment to funding this venture than the financial cost.

        Think what would have happened if people had refused to fund semiconductor research? I mean, really! Electronics on silicon??? That stuf is almost an insulator!!!

    • by Rogerborg (306625) on Monday March 25, 2002 @08:37AM (#3220449) Homepage
      • an earlier $2M that got dropped on this crackpottery.

      To be fair, most things that NASA does are crackpottery, until they work.

      But in this case, they really are pushing the boundaries of credibility.

      A (crack)potted history of Podkletnov goes something like this. Podkletnov throws together a bunch of superconducting junk that he has lying around his lab, and spins it up. He then waves some instruments at it, decides that he's seeing a 2% reduction in weight, and ascribes that to a reduction in gravitic mass (he can't test inertial mass, as he can't move the mass).

      So far, so good. Stranger things have happened through serendipity. Podkletnov has no theory to explain it, but that's incidental. All he needs to do to obtain credibility is to publish all details of his experiment so that it can be replicated.

      He fails to do this.

      Instead, he publishes a vague description of the apparatus, and continues to make the claims. He refuses to disclose further details, or to let anyone examine his apparatus. Eventually, his university becomes so tired of his antics that they terminate his employment.

      Various people with more money than sense try to replicate the experiment. Nobody who claims to have seen the weight loss will publish their details. Sound familiar? To anyone who reports that they cannot replicate the result, Podkletnov replies that they have the details wrong, but he still won't tell them what the details are.

      Enter NASA. With some input from Podkletnov, NASA spends $1 million and thinks it maybe kinda might be seeing a 2e-6 reduction, sorta. Podkletnov suggests a few changes, but he still won't just give them his details, and NASA spend another $1 million, at the end of which, they stop claiming that they even might be seeing an effect.

      And so here we are again. Someone's scraped together the spare change from other projects, and they've maybe, kinda, sorta got some details out of Podkletnov now. Or not. Who knows? Probably not NASA, and almost certainly not Podkletnov.

      Podkletnov is a poor scientist, but a great publicist. Maybe that's what gets funding in NASA these days. It certainly gets publicity, as this discussion proves.

    • In order to make Interstellar travel a reality, we need to make a revolutionary jump in technology. Since examining the known laws of physics isn't producing the answers we need, NASA is looking at the prospect that we may not understand the nature of the universe as well as we like to think we do. We need to remember that the "Laws" of physics are theorys that have merely been proposed based on experimentation and observation. Throughout scientific history there have been some discoveries that some things we though were proven absolute, were only true for the many different situations in which they had been tested. The ability to shield an object from the effects of gravity is pretty far fetched, but so is interstellar travel. NASA is going to have to spend a lot of money checking out some radical theories. In the end most of the research won't turn up anything useful. In some cases it will turn up usefull information but not prove what they are trying to prove. One of the important things to note here is that this kind of research needs to be funded by the government because private industries just aren't likely to invest money on concepts that are such longshots, and would take far too long to produce a return on investment. It's true that most of these ideas won't pan out, but through NASA, our government is making a long term investment in our futures. Maybe this isn't as important as some more short term needs like Welfare and Defense budgets, but that's why we spend billions on those things, and millions over years on ideas like this one.
  • by Jucius Maximus (229128) <zyrbmf5j4x&snkmail,com> on Monday March 25, 2002 @02:44AM (#3219583) Homepage Journal
    There will be a whole new rush of 'effortless weight loss' products on the market. (Not mass loss.)
    • by martyn s (444964)
      Actually, perhaps, mass loss. AFAIK, mass is the constant of proportionality between weight and acceleration. If the rotating disc is lowering the weight of something, still on Earth, why do you assume the disc is disrupting gravity and not lessening the mass of the object?
  • Interesting but... (Score:3, Insightful)

    by Eric Damron (553630) on Monday March 25, 2002 @02:46AM (#3219592)
    If the experiments succeed it may give us some insite into gravity but don't look to this device to free us from the bonds of Earth.

    A super cooled, electrically charged, rapidly spinning super conducting disc that reduces the gravity field above the disc is interesting. However, taken as a whole, the entire system would still crash to earth.

    Sort of like putting a sail on one end of a skateboard and a fan blowing air on it on the other end. It still isn't going anywhere.
    • Let me give you an example of a practical application of this technology.

      Take a wheel, with the axle horizontal and place the axle directly over the edge of this thing, so half the wheel has its gravity reduced, and the other half doesn't. Then there is a net torque on the wheel. It will spin. You can put a generator on the axle and make free energy for nothing.

      In other words, if this thing works, you can make a perpetual motion machine. You can interpret that fact any way you want -- I interpret it to mean this anti-gravity thing is a crock of shit.

      • wrong, because the perpetual motion machine would include the super-cooled disc spinning at 5000 rpm ... it probably takes alot more energy to spin the disk them you would get back from your wheel :)
      • by digger3001 (562414)
        You can put a generator on the axle and make free energy for nothing.

        Free except for all the energy you spent spinning that disc 5000+ rpm's...it's not free energy, it's a transference of energy in that case.

      • by Xaoswolf (524554)
        Actually, a pertetual motion machine works without the assisstance of other machines and uses it's own energy. What you are saying is no different than putting an electric engine beside the wheel, and attaching a belt to it and saying it is a perpetual motion machine.
  • Is this just me or is there a grain of truth to this.... Once again we see Humans trying to break another law. No matter what the law, or how important it is, we want to break it. Gravity, conservation of energy, prohibition: pick a law and humans can be seen diligently trying to disobey it. Is it good for us to do so? We don't care, just as long as no-one ever tells us what to do. Oh well, we've been dangerously willful beings thus far and I guess since we're still hanging around... Maybe we're just lucky punks.
  • AntiGravy (Score:3, Interesting)

    by tcd004 (134130) on Monday March 25, 2002 @02:57AM (#3219641) Homepage
    "James Cox, editor of AntiGravity News, lists no less than seven major classifications of anti-gravity devices, from those based on superconductivity, to those that exploit properties of gyroscopes and purported anomalies in nuclear physics or quantum mechanics. Cox himself is working on an anti-gravity backpack that he claims is nearing the patent stage. He is currently seeking funding to develop a commercially viable prototype."

    I love how the web has made every Kook with a website an "Editor"--and a reasonable source for story on a scientific topic.

    The government is turning welfare moms into prostitutes! [lostbrain.com]
    tcd004
    (Editor, Lostbrain.com)
    • by Bronster (13157)
      I love how the web has made every Kook with a website an "Editor"

      As opposed to the printing press?

      (totally off topic - but all the web has done has made it even easier to be a kook)

      Bron (Scientific Advisor: Slashdot.org, On The Web, In Crayon)
  • by oo7tushar (311912) <slash.@tushar.cx> on Monday March 25, 2002 @03:02AM (#3219663) Homepage
    will finally get their flying car, perhaps from the german scientist? http://www.viewaskew.com/tv/leno/flyingcar.html [viewaskew.com]
  • PM Article. (Score:2, Insightful)

    by stuffman64 (208233)
    Popular Mechanics ran something to this effect sometime ago. It can be found online here [popularmechanics.com].

    I can just imagine it now, getting spam that reads: "Do you weigh over 200lbs? Well we have the solution for you! Loose over 4lbs INSTANTLY! Thats right, INSTANTLY! NO gimmicks, NO drugs, just pure science! Only $600,000! Act Now!"
  • by Calrathan (114381) on Monday March 25, 2002 @03:12AM (#3219708) Homepage
    Is this effect similar to that of the levitating frogs? [I dont have a link handy... anyone care to help?]

    If so, could the rotating simply be acting to create a focus point of magnetic energy at some point on the axis of rotation, above the superconducting disc? If the object being tested has any magnetic substace in it at all, then a strong magnetic field could cause it to seem less weighted, right?

    I also question the use of the Cavandish balance to measure the mass of the item above the spinning disk. We're dealing with a superconductor in a magnetic and electric field... What is preventing this device from causing some strange magnetic effect. What about ionization of the air around this device?

    These are just my inital reactions to the article, and I'm no Physics expert. What are your thoughts, friends?
  • by thogard (43403) on Monday March 25, 2002 @03:43AM (#3219763) Homepage
    All the space probes we can measure are slowing down. The ones where the effect is most oticed are teh GPS sats since they have real good clocks and we know where they are and the long distance Pioneer and Voyagers. NASA isn't sure why this is happening. They know its going on and need to find out why.

    If I do an experiment where I can show gravity doesn't work like its expected to, they will look into it. Most of the time the result is that somone put an Acme magnet in the wrong place. NASA doesn't care what the experimentor's (or crackpot's) theory is, they want to duplicate the experiment and try to find out the real reason for the change in mass. If your respected enough to do an expirment, its worth their time to look into it even if your theory is the disk weighs less because of the magic elves.
  • hmmm...seems fishy (Score:2, Insightful)

    by andrewtea (208706)
    as always, extraordinary results require extraordinary proof

    as much as id love to see this kind of stuff a reality, this particular claim seems off to me. It happens way too often in the physics community that someone claims to have made some breakthrough, be it in superluminal light pulses, or cold fusion and really they are just full of it.

    it seems most often that theyve put so much of their life and time into their work that when they dont get anything meaningfull they either fudge the results or "see" what they want to.

    unfortunately that is probably the case here..a dead giveaway is Mr P's (i cant spell his name) initial secrecy, that always kind of says something about the authenticity of the claim...it also doesnt help that his hosting university throws him out and noone else can reproduce his claim...on the grounds that its too complicated to set up properly. bs

    but im always the skeptic...even if im hopeful

    good for nasa though in actually staking out the claim...and if they need to killing the hype

    id like to know how Mr P measured his weight change too...if he use similiar ballances to nasa or something else he cooked up
    • It happens way too often in the physics community that someone claims to have made some breakthrough, be it in superluminal light pulses, or cold fusion and really they are just full of it.

      Huh? It doesn't happen often at all. Out of the tens of thousands of physicists producing all those experiments and journal articles, maybe once every few years someone makes an extraordinary claim. The vast majority fit in just fine into modern physics thought.
  • by Linuxthess (529239) on Monday March 25, 2002 @03:48AM (#3219778) Journal
    For a second I thought it was April 1st.

    The article states "The Podkletnov effect suggests it may be possible to effectively reduce the mass of the ship, thereby reducing the overall energy needed for acceleration."

    Now as every semi-educated idiot knows, Mass and Weight are two different measures. Mass is an immutable constant, while weight is strictly based on the strength of the gravational field.

    In other words wieght can vary, but mass will never.

    I did a Google search on this "paranoid" scientist and I couldn't find anything negative.
    ---------------

  • Anybody know of any beginners guides to physics, preferably on the web I can start reading?

    I read 'The Physics of Star Trek' recently, and found that to have a very fascinating insight into how likely some of the fictional technology is. The author did a good job of explaining some of the more complex stuff in terms I could understand. Now I hunger for more. Anybody have a site or a book they could point me to?
    • Well, there's a guy at NASA's Glenn Research Center, Marc Millis, who does a very good job explaining the physics behind the reasons why interstellar travel is such a challenge, and what kind of technological solutions are needed to explore the stars. The best page on his site is Warp Drive When? [nasa.gov].

      If you read this you'll understand why NASA is spending money on this kind of science. If we're going anywhere farther than the planets then we need a breakthrough. They are not ready to ignore the possibility that this guy might be right, even though he's acting like a crackpot.

      And really, $600k -- or even $6M -- isn't that much money from the NASA budget, especially when spread over several years. I work on NASA projects and they spend hundreds of thousands per researcher per year to build and test prototypes of scientific instruments, rocket motors, what have you, just to incubate technologies that NASA thinks will be useful in the future. And it keeps industry and its talent ready and able to perform on future contracts.

  • ..they're approaching the Holy Grail from, if not wrong, then atleast from a difficult angle. I mean, according to the article, Podkletnov:

    "..insists the gravity-shielding effect only occurs when all the experimental conditions are precisely right."

    So we need a disc of special superconducting material spinning at just the right speed, etc., and then and only then the effect occurs.

    If they can replicate the 2% weight loss in the experiment it'd be great. But only when they can tell what really triggers the effect, and how to do it with larger discs and at any RPM, then I'll raise my hat to true science. This is just lucky engineering, atleast to my views.

    Hmm I wonder what would happen if they put multiple discs on top of each other. Would it multiply the effect..?

    Okay, okay, maybe I should finally read that report he wrote some time ago. ;)
  • podkletnov's paper (Score:5, Informative)

    by Jeremy Erwin (2054) on Monday March 25, 2002 @04:04AM (#3219819) Journal
    Evgeny Podkletnov and Giovanni Modanese have posted one of their papers on the arXiv: http://xxx.lanl.gov/abs/physics/0108005

  • This "research" has all the signs of pseudo-science. The results are alledgedly reproducible, but only when conditions are "exactly right" which they never seem to be when other people try to repeat the tests independently. The researcher himself won't help other people or publish more than vague information because, so he says, he's afraid of being ripped off. As a result, he's has been thrown out of the academic institution where he used to work. No plausible theoretical underpinning for the effect, and plenty of scope in the test setup outlined in what little has been published for other effects to be present which might be confused with the result that's claimed, especially by someone who - to put it charitably - may find it difficult to maintain full scientific objectivity when considering the results.

    NASA must have contracted a bad dose of the "but they said Einstein was wrong" meme to even consider getting involved in this quackery.
  • by rufusdufus (450462) on Monday March 25, 2002 @04:21AM (#3219856)
    The main bogus part about the claim is that there is no theory to back up the supposed effect. Thus, what we have is an effect; however say that it is anti-gravity is presumptive. There are many things that could cause effects claimed by the so-called evidence, such as a jet stream of particles. Of course, this effect has never been replicated by any reputable scientist, thus we are left with a claim of some effect who's discoverer in the very least jumped to the conclusion of anti-gravity, yet more probably just made it all up.
    • by Zapman (2662) on Monday March 25, 2002 @09:54AM (#3220689)
      Er, no. If you've read "The Structure of Scientific Revolutions", you'll see that 95% of all science is hidebound to their assumptions. Great leaps forward happen when enough young scientists (not bound to the previous theory, since they didn't build their career on it) find enough data that doesn't 'fit' with the current theory.

      Once the weight of these new scientists is great enough, there is a violent 'paradigm shift' to a new theory that fits all the old data and all the new.
      • Once the weight of these new scientists is great enough, there is a violent 'paradigm shift'

        AH-HA! So this anti-gravity research is a plot by the old scientists to reduce the weight of the new scientists, and therefore retain their hold on power. Ingenious! I'd better eat more hamburgers to help counter this conspiracy.

  • Unfortunately, this seems to be one more symptom of NASA's desparate search for something, anything, to recapture its former glory. Yes, it makes sense to investigate valid scientific experiments which yield potentially valuable anomalies, like Podkletnov's supposed results. But the field of science thrives on peer review. A 'scientist' who is not willing to submit himself to peer review ought to raise some red flags somewhere... Podkletnov's claims seem suspiciously similar to those of proponents of perpetual motion machines and cold fusion.

    The basis of science today is in testing phenomena and reproducing results. Podkletnov refuses to submit to this basic tenet of scientific society. He claims that people will steal his ideas and take his credit - yet if he's well known enough that NASA, let alone the LA Times, has heard of him, such intellectual thievery ought to be very difficult. In addition, by publishing a paper with all his procedures and results, he would not only prove that such "gravity shielding" phenomena do exist, he'd be able to defend himself against future intellectual thievery, and he would allow other scientists to build off of - note, not steal - his work.

    However, Podkletnov chooses not to publish his actual procedures. This makes his experiments functionally untestable. This is fortuitous for him if he is a fraud. That way, if NASA does manage to discover "gravity shielding", he can claim that their procedure was his, and cash in on their prestige and fame. If NASA fails, as they are likely to do, he can simply claim that they didn't do it quite right, and continue to refuse to release his results. Given that he's kept the chemical composition of some of the components of his apparatus, namely, the spinning disk, secret, it's hard to see how NASA would succeed even if his claims were valid. Finally, if, as Podkletnov claims, "dozens of people" have matched his results, we could expect at least one of them to have come forward by now. Certainly, they can't all be hiding their data for fear of thievery - are we to suppose that not one of "dozens" of scientists has the bravery, initiative, far-sightedness, or even plain greed to publish these results, which could have such an impact on the world if verified? That seems highly unlikely...

    It's somewhat disheartening to see an institution like NASA following pseudoscience like Podkletnov's "gravity shielding". With current budget cuts, NASA would be much better off spending its diminishing money on developing technology that already exists, rather than chasing implausible alternatives. Everyone would profit off of an alchemist's ability to turn lead to gold, or a perpetual motion machine, or cold fusion, but, because those have been shown to be so implausible, for various reasons, we don't see serious research institutions researching them. "Anti-gravity", at least of Podkletnov's variety, should be placed in the same category, at least until the 'scientist' is willing to back up his claims with some real, verifiable, and repeatable procedures and data.

  • this article many years ago, and people at that time almost believe that an object will lose weight when it spins fast enough. Some even started to think that there's a gigantic core spinning inside a round shape UFO, ensure its anti-gravitational movement without using any combustion engine at all.

    It's until now I realized none has yet confirmed yet. Oh I shouldn't have read all these damn UFO-science books. :/
  • by ukryule (186826) <slashdot@@@yule...org> on Monday March 25, 2002 @04:48AM (#3219906) Homepage
    From the article:
    The law of gravity is one of science's most sacrosanct principles; any breaching of its walls would represent a major threat to the current theoretical framework.

    Really? One of the few things I can remember from my Physics courses at school is that noone understands why gravitation mass is the same as intertial mass. The closest anyone's got to an explanation is Einstein with his Equivalence Principle [uidaho.edu], but even this seems a bit woolly (only works in a uniform gravitational field). So there are still aspects of mass (and so gravity) that are not fully understood.

    Of course, this experiment sounds rather dodgy, and it's unclear from the article what they're measuring. Got me wondering though ...
    • noone understands why gravitation mass is the same as intertial mass

      Strictly speaking, they are not the same. That's why the gravitational constant (G) exists - it's the "scaling factor" between inertial and gravitational mass. Hence, g = GMm/(r^2), not Mm/(r^2).

      Inertial and gravitational mass are equivalent, which is very nearly what you said, and probably what you meant. That's the thing that noone understands. It is the only force that behaves like that, and also the only force that we have only seen one charge for (eg electrical charges come in positive and negative, magnetic charges come in north and south, etc). All mass attracts all other mass, there is not a different type of mass that repells "normal" mass, at least as far as we've been able to see. I find that as intriguing as the equivalence of inertial and gravitational mass.

      Cheers,

      Tim
      • by barawn (25691) on Monday March 25, 2002 @10:42AM (#3220927) Homepage
        (first, correction in your post: you want F = GMm/r^2, not g: g is 9.8 m/s^2, which means it can't have any variables in it. it's g = GM/R^2, where M is the Earth's mass, and R is the Earth's radius)

        Not really: G is a conversion factor between mass and force, making it a coupling constant (like Coulomb's constant) - it's more a field strength than anything else.

        Note that you can make G go away with a convenient choice of units (mass is mass is mass: they would still have the same units - grams - even if you had inertial and gravitational, just like kinetic energy, potential energy are both measured in joules). For the rest of this, we'll work in units (call them 'statgrams') such that G = 1 Newton-m^2/statgram^2.

        When people say that gravitational mass is the same as inertial mass, we mean: force is equal to inertial mass times acceleration, and force is equal to gravitational mass of the two objects divided by radius squared.

        OK, so F = (m_i)a , and F = (m_g)M/r^2. Now, when we say that gravitational mass is the same as inertial mass, we mean that if you set these two forces equal, so gravity's providing all the acceleration, the inertial and gravitational masses cancel, that is, g = (m_g/m_i) M/r^2 goes to g= M/r^2.

        There are several ways to test this, and all any of them can test is that the ratio is constant (indep. of radius, indep. of inertial mass, etc.) and so we set this constant to 1.

        It's a subtle difference, but there: there're two different things that're in the force equation, a coupling of matter to matter (G) and a conversion between gravitational mass and inertial mass (m_g/m_i). Setting one of them to 1 doesn't necessarily set the other to 1, but since they're both 'unit choices', you can freely set them both to 1. The important thing is that since all derivatives of m_g/m_i appear to be zero, it IS merely a unit choice. If there WAS a difference, you could set G to 1, but not m_g/m_i.

        One other thing: quantum-mechanically, it's not surprising that gravity is solely attractive: it's a tensor (spin-2) field, which IS solely attractive. That part's understood (We know that a spin-2 field can mimic linearized GR - that is, GR in the weak field limit).
        • One other thing: quantum-mechanically, it's not surprising that gravity is solely attractive: it's a tensor (spin-2) field, which IS solely attractive.

          I think your terminology is correct here, but the reasoning is backward. There is no quantum field theory for gravity that has been tested in any way. People realized that a tensor boson would create an exclusively attractive force, so this is a candidate theory to explain the gravitational force. Hence the supposed "graviton". So to say that we know gravity is attractive based on quantum field theory is incorrect. We know that gravity is attractive based on experience. We have a candidate quantum field theory of gravity which has two major drawbacks: 1) it's untested (no exclusive predictions can be observed with our present technology). 2) it's inconsistent with GR, which has been tested to extremes.

          I'm not an expert on general relativity, but AFAIK the equivalence principle, which is at the heart of GR, is in a sense the statement that gravitational mass and inertial mass are identical. In Newtonian theory, gravity is an external force that attract masses. In GR, Newton's gravitational force is a "fictitious force", not a force proper. A non-inertial reference frame is approximately the same as an inertial reference frame with an additional fictitious force. Mass (for some reason) creates curvature in spacetime, which is like a non-inertial reference frame in flat space-time.

          I've never really understood the need for a quantum theory of gravity, since gravity is not a force to begin with. I hope that some string theorists can set me straight on this some time. (I just need the guts to walk down the hall and sask them point-blank. My fear is that I won't understand the answer.)

          As for Podkletnov, I'm genuinely surprised that anybody is taking him seriously. (taking seriously = non-zero funding to investigate his claims.) The LA times article suggests that he is affraid of the credit being stolen if he publishes the details in a peer-reviewed journal. This is crazy since publishing the explicit experiment and its results is his only gaurantee that he will be recognized as the discoverer of the effect!

          His other paper that he put on the preprint servers last year was a masterpiece of bogus science, and I can see why he has such a hard time holding a job or publishing anything. There were several logical flaws in that paper, and the experimental technique was horrible and imprecise. For example, there were no measurement errors quoted, which wouldn't even earn him a passing grade in a high school physics course.

          My favorite line of reasoning in the paper was that the impulse imparted by his "anti-gravity beam" was proportional to the mass of the test subject. Thus, by extrapolation, if he were to put a hugely massive test subject in the beam, it would receive more kinetic energy than the amount of energy put into the beam. He then sites this as a violation of the equivalence principle! No, it's a violation of conservation of energy, and no one in their right mind would believe that he's observing violation of conservation of energy based on an absurd extrapolation, hundreds of times further than his actual data reaches. If you think about it, this "little goof" invalidates his whole anti-gravity explanation.

          After reading that, I just shook my head in amazement. And now he's getting folks at NASA to take him seriously? NASA is desperately hurting for funding, and really shouldn't be dabbling in quackery right now.

          - Topher

          • Not quite - linearized GR can be viewed as a spin-2 field theory. It's not a working quantum field theory, though: why? Because in QFT, a spin-2 field theory has problems with stuff like tachyons and other weird particles appearing. This may not be a limitation of a spin-2 field theory (though it really looks like it is... sigh) as it may be that our understanding of QFT is just that bad (it was for a long time, before renormalization became 'en vogue'). QFT has a lot of semi-ad hoc rules right now, so it's entirely possible that a spin-2 field is exactly what gravity is, and we just really are still that poor at field theory that we can't describe it. This is basically the way things are being approached now.

            However, if we assume GR is true (which it looks like it is, in a gross sense) then at some level, it has to be spin 2, as in the small field limit, it IS a spin 2 field.

            So, we really have two observations:

            1) gravity is a spin-2 field. (not a quantum field, true, but I didn't say it was a quantum field :) )

            2) spin-2 fields in quantum field theory are solely attractive.

            Based on this, we can say it's not a surprise that gravity is solely attractive. We CAN'T say that gravity is a spin-2 quantum field in the sense that we understand quantum fields now, but we can say it's not really a surprise that gravity is solely attractive.

            That is, if you didn't have the volumes of empirical data saying "gravity is solely attractive", your first guess would be that gravity is solely attractive based on the fact that it is a spin-2 field in the linearized approximation, and spin-2 fields in quantum field theory are solely attractive. It's similar to calculating energy level transitions using quantum mechanics: it shouldn't work, you're crossing realms of validity, but it does, because it's a general 'macroscopic concept' - in this case, energy. In the spin-2 gravity case, it's conservation of momentum which is driving the spin-2 necessity. A theoretician would probably say "conservation of momentum is such a strongly held symmetry that we can bend it a little with no problem" or some bull like that (no joke - I've heard similar).

            As for Podkletnov, I agree that he's a quack (will never argue that) and that his research is sloppy and all the extrapolations/reasonings are junk. The main thing that people are trying to replicate, though, is not the antigrav beam (which I almost printed out to go alongside the other antigrav devices I've seen on arxiv) but the anomalous mass reduction over a spinning superconductor. This one... ok, I can see the desire to try to replicate it (especially because they had trouble previously) but it probably won't work (PROBABLY... but, eh, who knows).

            That said, I should also point out this is almost definitely funded via Millis's BPP program, which is a perfectly valid program. There's some random financial realm of thinking which basically says "if you have an idea which has a very low probability of success, but an infinitely huge return, you should invest some small portion of money into it", and this is what Millis's program is being funded out of. It's valid. They'd probably be better off futzing around with the Casimir effect, but that's probably next year. :)
      • Is anti-matter positive (same as regular) gravity? Whats the theory on this? I don't suppose they've made enough of it to run an expirement...
    • I suspect that the reason that gravitational mass and inertial mass are the same is that gravitational mass is derived from inertial mass via time dilation. I can't do the math, but remember that the deeper you are in a gravitational well, the slower time is. So an electron will (from the nucleus point of view) spend more time deeper in the well, which would result in the nucleus being pulled in that direction. From the electrons point of view (it's the one doing the dancing) it spends the same amount of time on both sides of the nucleus. So it has no net change in momentum.

      This would obviously be a very weak effect, but then gravity is a very weak effect. And, as I said, I can't do the math, so it might be wrong. But that's the way it seems to me.

  • by QuantumG (50515) <qg@biodome.org> on Monday March 25, 2002 @05:25AM (#3220005) Homepage Journal
    Antigravity is a lot older than 1992 kids. That's just when it became fashionable to be an antigravity crackpot again. Here's an idea, rather than wasting your time trying to make antigravity devices to power some future space ship, why dont you spend your time trying to make a gravity device that we can put on our existing space ships and space stations? A decent gravity simulator is desperately needed for the human mission to mars (which may never happen in this economic climate) and other long term space projects, and frankly, if you cant make a gravity device, what chance do you have of making an antigravity device?
    • by autopr0n (534291)
      What's wrong with centerfugial force?
      • The biggest thing wrong with ceterfugial force is that there is no such thing. There is however centripital force.
    • by barawn (25691) on Monday March 25, 2002 @10:55AM (#3220990) Homepage
      Presumedly, if there is a way to counteract the effects of gravity (and that presupposes that's REALLY what this is doing) there'll be a way to simulate the effects of gravity.

      That said, unless you can do VERY weird things, simulating gravity REALLY sucks. Think about the energy cost! If you can 'simulate' gravity, then all the matter that's put in that 'simulated' gravity field suddenly has a LOT of potential energy. Where do you think that potential energy has to come from? Gravity can't be free.

      We don't need simulated gravity. We need ways of dealing with zero-gravity. If you absolutely have to have a gravity-like force, spin the ship. The only problem with that is that you need a BIG ship so Coriolis forces and a sharp pseudogravity gradient don't screw you up.

      Simulated gravity won't happen until we are as good at manipulating gravity as we are at manipulating electromagnetism. The initial gravity field would take A LOT of energy to set up (hell: it took the Earth's mass times c^2 to set up the Earth's gravitational field! We sure as hell don't have easy access to that much energy!)
      • I should imagine that by the time we can make 'artificial gravity' (or antigravity), we'll have equipment to generate enough thrust for a long enough time to continuously accelerate a Mars mission ship at a rate such that the acceleration alone is enough.

        Make a spacecraft that can, say, put out enough thrust to continously accelerate at 0.5G acceleration. Flip the ship at the halfway point, and decelerate at 0.5G.
  • cross post (Score:2, Funny)

    by Prowl (554277)
    shouldn't this belong in the "outrageous vendor lies" thread.

    still, i won't have to worry about my diet...
  • by cybrpnk (94636) on Monday March 25, 2002 @06:02AM (#3220111)
    I have yet to see ANYBODY in this field tie the Pokletnov claims to the mainstream theory of gravity believed by most particle physicists, which is that it is caused by a particle called the Higgs Boson. What's interesting is that these mainstream physicists share many traits with Pokletnov to the untrained eye - they haven't really found the Higgs particle yet, they just think it's there because it ought to be, and without understanding of some really DEEP math the Higgs at first blush seems to be just as much handwaving as anti-gravity. Some of the best public-consumption stuff on the Higgs is to be found here [uct.ac.za], something about the (so far unsuccessful) search here [about.com], and an audio discussion with the inventor of the whole concept, Dr. Higgs himself, here [umich.edu]. If you want to get into the serious math of the Higgs (good luck) one place to start is the bottom of the web page here [tripod.com].
  • The last time this came around, i was pondered what this would actually mean.

    Consider a localised column around the earth in which gravity is lessened. This means that the potential energy is higher in this area... here on earth we have very negative energy, and out to infinity we define zero energy. The area of lesser gravity has a higher potential energy.

    The upshot of this is that it requires a force to "push" something into this area of microgravity. Why? because otherwise you could have two stairwells, one for going up in the microgravity area, and one for going down (normal gravity). You could get energy for free.

    So, if your missile, or what ever, has sufficient energy to make it into the microgravity column, it slows, and then comes out the other side, at its original velocity. If it doesnt have this critical velocity (let's call it escape velocity), it bounces back. At its original speed. Ouch. Most notably, if you put your arm in there, your heart can't pump the blood with enough pressure to keep the blood in your arm. Bugger.

    I think it is kinda interesting, not only because it is fundamentally a cool thing, but all the cooky side effects that could come about from it.

    • The upshot of this is that it requires a force to "push" something into this area of microgravity...You could get energy for free.

      No, there is no need for an external force. The energy comes from the field that is responsible for the local reduction in the gravitational force. When an object enters it and gains energy, the field must somehow restore its energy level, or fade. That comes down to drawing more energy from whatever's powering it. Assuming the field is artificial, that will probably, ultimately, be an electrical supply of some sort - a battery will be drained, more coal will have to be burnt, whatever.

      You're not gaining free energy (which is impossible, at least macroscopically, and for "long" periods of time), you're just changing its form.

      Cheers,

      Tim
  • hmmm (Score:2, Informative)

    by Anonymous Coward
    This guy did a presentation of his work at sheffield university (UK). The major problem seemed to be his measurements relied on a weight loss. He used liquid nitorogen to cool his superconductors down and spinning something at several 1000 rpm tends to heat stuff up. Some of the liquid nitrogen evaporated away as it was not sealed in properly. Virtually everyone there felt this explained the weight loss.
    Plus his error analysis was crap and also had graphs consisting of a number of smiley faces IIRC.
    Also for a year, some RA was hired by Sheffield uni to try and recreate his results. Yes there was a weight loss effect once (out of many many attempts at the experiment) but the guy who did the experiment did some proper error analysis and concluded it was an error. In the end, they could not recreate his experiments.
    Thats not to mention the anecdotes he used to explain his accidental discovery of the effect. One of his colleagues was smoking his pipe on the floor above when the smoke hit an invisible column and rose (or something similar to that).
  • Wow, this "MARGARET WERTHEIM" is a total idiot. Anybody who even took an "intro to philosophy" course and didn't sleep through it would know that any talk about "breaking the laws of nature" is complete nonsense. If this experiment turns out to be right, the consequence will not be that the laws of nature were broken, but that they are different from what we were expecting. Maybe this MARGARET WERTHEIM learned in journalism school to generate interest through cliches and conceptual nonsense, and maybe that's good enough to fool LA Times editors, but I can tell you, this doesn't reaffirm my faith in American journalism.
    • You've apparently never had an editor. She may not have even wrote this line. Would it make you feel better if she had said "breaking the laws of nature as we know them"? Let's try not to be a pedant. This article was after all, intended for the lay reader. (You didn't notice any theoretical/philosophical formulas or calculations in the article for example.) LA Times is not New Scientist or ieee.org.
  • by Observer (91365) on Monday March 25, 2002 @11:31AM (#3221201)
    One point that belatedly struck me about this guy's claim: the apparatus that shows (alledgedly) this effect uses a spinning rotor, and spinning rotors seem to have an amazing ability to attract pseudo-science.

    Maybe they somehow generate some sort of bogosity field;) Or perhaps it's just because so many people have at one time or another personally encountered the bafflingly counter-intuitive behavior of a toy gyroscope when you try to alter the axis around which it is spinning, and it tries to move off in an approximately 90-degree offset direction. There was a time when I was studying physics at university when I could write down the relevant equations and calculate what would happen, but even then I never intuitively understood the "cause" or where this unexpected force "came from". Quantum theory and relativity seemed transparently obvious in contrast.
  • Superconductors possess a very interesting phenomena. They are anti-magnetic. Several years ago I attended a physics day at a local university. In one of the exhibits a grad student was demonstrating this property. He place a small magnet on a superconductor and poured liquid nitrogen on the superconductor. The magnet rose and floated about an inch above the superconductor. I asked the grad student what would happen if he repeated the demostration and placed a supermagnet (a rare earth magnet) ontop the superconductor. He said he was game. We stole a supermagnet from another demostration and conducted the experiment. When the liquid nitrogen was poured on the superconductor, the supermagnet shot up in the air like a bullet, ricocheted off the ceiling and rattled around the room. The antimagnetic property of a superconductor is not polarity oriented. The effect will work no matter which pole is placed ontop the superconductor. It is a repulsive force not an attractive force.
    Since superconductors already possess one unique attribute (anti-magnetism), it would be very intriguing if it might possess a second (anti-gravitiationl). The other passing thought is that the world has longed for an anti-gravitational engine, but maybe it was right in front of our noses all the time but it was called something else, an anti-magnetic engine. The Earth along with many planets and stars in the universe possess magnetic fields.
  • Gravity holds all of our stuff down, so let's not be so negative about it. All kidding aside, from a physics point of view, anti-gravity is like de-accelleration - there is no such thing. There is accelleration with a reversed vector -- which has the same effect as so-called "deaccelleration." With gravity there is simply the Graviton. It is just a theoretical particle but it fits in well with Super String Theory and Quantum Gravity. I suppose it implies there is an Anti-Graviton, but the article in question doesn't suggest the manufacture of Anti-Gravitons.

    --Peter

    T( H)GSB [slashdot.org] Apr 21-27

  • In short, if we are serious about space travel, we need a quantum leap

    Wow, I thought the quantum leap effect was restricted to time travel!

    -
  • Falsifiability (Score:5, Insightful)

    by jfengel (409917) on Monday March 25, 2002 @12:44PM (#3221754) Homepage Journal
    I am concerned that NASA is funding non-falsifiable research. It is certainly true that it would be mind-blowingly neat if this experiment happened to demonstrate something that we couldn't explain.

    However, suppose the experiment fails to demonstrate the sought-after effect. This does not constitute a victory for the existing models, because Podkletnov just says, "Oh, you didn't use the right superconductor," or the right temperature, or something.

    There is no way to disprove his theory. That's called "non-falsifiable". Non-falsifiable theories are generally unproductive because you can never stop trying to prove them; you're caught in an infinite loop. Eventually you just lose interest, or start to apply Occam's Razor.

    It does not bother me that NASA should pursue research with a low likelihood of yield when the potential benefits are high. But whenever someone posits a non-falsifiable theory you must be suspicious, because it's the mark of somebody who is trying to get you to waste time and money.

    Note that "falsifiable" is different from "not easily proveable". I can't really go out and check that those points in the sky are really massive hot balls of gas. But at least theoretically it's possible, just not convenient. And I can run other tests which could disprove my hypothesis. I can prove that they're not real close, for example, by sending up a rocket ship. I can check that they happen to produce light in the same fashion that really hot things do. If these tests fail, you know that my theory is wrong.

    Inventing non-falsifiable theories is easy; you just leave a variable unbound. (That's the more general, and more useful, form of saying "you can't disprove a negative." You _can_ disprove a negative; I can prove that there's no elephant between me and my monitor right now.)

    Because creating non-falsifiable theories is both easier and less productive than creating real scientific theories, but make it possible to fool people into believing something they want to believe, such theories must be treated with extreme suspicion, especially when somebody has something personal to gain out of it. The theory is not necessarily wrong, but the odds decrease drastically, to the point where the probability * cost is lower than the potential value.

    The potential value may be very high here, but $2.6 million is non-trivial money, even for NASA, and the probability is vanishingly small.
  • by Courageous (228506) on Monday March 25, 2002 @05:46PM (#3224315)
    Unlike the majority of other commentors in this theread, I'm unconcerned with the validity of the research. I find something else interesting. Suppose that a gravity _shield_ of some form really could be made. Suppose, for example, that whatever field or particle effect that exists between two entities could be fully or partly interrupted. If that could be made to happen, what would the effects be on the two intervening masses assuming that all of the rest of our assumptions about the laws of physics would hold? In other words, what would be the _projected effect_ of a real gravitational shield?

    There are, in my mind, many different questions:

    1. Over what range would the shield have an effect?

    2. Could the shield shield itself?

    3. Is it bidirectional?

    4. If particles in the umbra of the shield are no longer fully subject to gravitation, how would the effect of other forces be expected to perturb the particles?

    4a. For example, how would ordinary air in the umbra of the shadow be expected to behave?

    5. If an object in the umbra of the field was subject to reduced or near zero gravitational force, how would such an object be expected to behave in regards to angular momentum forces in effect on a rotating planetary body?

    And so on.

    It seems to me on superficial consideration that a "gravitational shield" would likely cause extraordinary and obvious side effects in even the most simple of circumstances. Living as we do in a heavy gravity zone, we take all of the effects of gravity for granted. An area of even limited exemption to gravity would likely have highly perturbing results in its domain of influence.

    Anyone want to play this game?

    C//

Money is the root of all evil, and man needs roots.

Working...