Become a fan of Slashdot on Facebook


Forgot your password?

NASA Still Trying to Verify Anti-Gravity Claims 430

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This discussion has been archived.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 yokimbo ( 525881 ) on Monday March 25, 2002 @02:34AM (#3219526) Journal
    Hey,maybe now the fattest guy in the world could actually support his weight. Now to get a motor strong enough to get him spinning that at 5000 RPM.
  • by adminispheroid ( 554101 ) on Monday March 25, 2002 @02:42AM (#3219564)
    This has been going on for a while. See the most recent note [] on this subject from Bob Park's "What's New." He refers to an earlier $2M that got dropped on this crackpottery.
  • by Monkelectric ( 546685 ) <> on Monday March 25, 2002 @03:01AM (#3219660)
    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 ) on Monday March 25, 2002 @03:41AM (#3219760) Homepage
    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 not free energy, it's a transference of energy in that case.

  • Quote: "Gravity has NOTHING to do with mass, anyone who took high school physics should be able to tell you that."

    Actually, gravity depends on three things,
    1) The mass of the object that is being attracted
    2) The mass of the object 1) is attracted to(typically much greater than the mass of 1))
    3) The distance separating the two.

    This relationship is called Newton's law of gravitation:

    F(gravity) = G*(mass(small)*mass(big))/(distance)^2
  • by dstone ( 191334 ) on Monday March 25, 2002 @03:59AM (#3219805) Homepage
    Gravity has NOTHING to do with mass, anyone who took high school physics should be able to tell you that.

    Check your high school physics notes again. Gravity has everything to do with mass. Gravity is the attraction of objects to each other because of their mass. Every object posessing mass has a gravitational field. The strength of that field is proportional to the amount of... wait for it... mass.

    If you witness/measure less gravitational force in a system, you can conclude at least one of three things, according to the high school physics you speak of:
    1. The universal gravitational constant has been reduced.
    2. One or more masses in the system have been reduced.
    3. The distance between the masses has been increased.
  • This sounds like.. (Score:2, Informative)

    by ( 513464 ) on Monday March 25, 2002 @04:01AM (#3219809)
    ..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. ;)
  • Re:Getting Dizzy... (Score:2, Informative)

    by xylon ( 552609 ) on Monday March 25, 2002 @04:01AM (#3219812)
    I think the article was suggesting that the object placed on the spinning disk was above it, and therefore stationary. And that would make more sense, I think...
  • 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:

  • 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 ukryule ( 186826 ) <`slashdot' `at' `'> 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 [], 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 ...
  • 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 [], something about the (so far unsuccessful) search here [], and an audio discussion with the inventor of the whole concept, Dr. Higgs himself, here []. 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 [].
  • hmmm (Score:2, Informative)

    by Anonymous Coward on Monday March 25, 2002 @06:26AM (#3220170)
    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).
  • Sustained rotation in a given plane (as when in a rotating craft) causes the inner-ear fluid to flow with the same angular velocity. If the head is moved out of the plane of rotation (as by turning your head), the continuing fluid movement in the old plane gives a sense of rotation in the new plane, even though no such movement is occurring. This disorienting and nauseating sensation, called Coriolis cross-coupling, is made worse by high rotation rates and short radial arms. Any movement not parallel to the axis of rotation will provoke Coriolis forces. An astronaut climbing towards the axis of rotation decelerates as he/she moves into an area of lower velocity, and experiences a force in the direction of rotation. An astronaut climbing down the same ladder feels a force pushing him/her against the direction of rotation. An astronaut running in the direction of rotation gains angular velocity and thus feels heavier, and one running against rotation feels lighter. Research at NASA Langley Rotating Space Station Simulator indicates that ambulation in the direction of rotation at rotation rates corresponding to greater than 0.3 g produces a disturbing heaviness in the legs, while ambulation against the direction of rotation is not possible below 0.05g. Finally, Coriolis forces act on any moving object; even fluid poured in a rotating field deviates in its course.

    Then there's the problem of gravity gradients. Centripetal acceleration (the 'gravity') is a linear function of radius; thus, there is a 100% gravity gradient running from the axis of rotation to the outer rim. An object weighing 10 kg on the 'floor' (rim) would weigh 5 kg if moved half-way up towards the 'ceiling' (axis). The percentage weight change an object moving from a point Ra to a point Rb experienced is given by:

    W1/W2 = (Ra - Rb)/Rb

    Thus, an object raised to a 1 meter shelf in a 4-meter rotating station (from Ra = 4 m to Rb = 3 m) would lose 25% of its weight. It is unknown how this sudden weight loss would affect materials handling; e.g., would a suddenly lightened box tend to fly out of one's hands?

    In addition, a 2-meter tall astronaut standing in a 4-meter rotating station would feel literally 'light-headed'; the head (nearer the axis of rotation) weighs 50% less than the feet!

    Despite these concerns, the gravity gradient appears to be the problem of least concern in designing a rotating habitat, and was considered a 'non-problem' in NASA's recent Artificial Gravity Working Group.
  • by barawn ( 25691 ) on Monday March 25, 2002 @10:49PM (#3226099) Homepage
    The spin-2 field derivation of linearized gravity is in "the big book of Gravity", Misner, Thorne and Wheeler's "Gravitation" - check out the linear field regime, and they show the spin-2 nature and give a few references. This is where gravitational waves come from, incidentally.

    Incidentally, my background's in experimental particle physics AND in gravity - grad and undergrad, respectively, just so you know where I'm coming from. The lack of a diple moment in gravity is just conservation of momentum: think of it this way.

    No scalar moment: conservation of charge, so (d/dt) sum over q_i = 0.
    Dipole moment: perfectly allowed: (d/dt) sum over (q_i*x_i) need not be zero.
    (all higher moments are fine)

    No scalar moment: conservation of mass, so
    (d/dt) sum over m_i = 0.
    No dipole moment: conservation of momentum, so (d/dt) sum over (m_i*x_i) = 0. (that is, dm_i/dt * x_i = 0, from cons. of mass, and m_i*dx_i/dt = 0 from cons. of momentum).
    Quadrupole moment: perfectly allowed: (d/dt) sum over (m_i*x_i^2) need not be zero. (that is, dm_i/dt*x_i^2 = 0, cons. of mass, 2*m_i*x_i*dx_i/dt need not be zero)

    Of course, you can substitute "dipole" for "vector", and "quadropole" for "tensor" before, so gravity is a tensor field (spin 2), and electromagnetism is a vector field (spin 1).

    Using a tensor field for gravity is therefore justified mainly from its presence in linearized GR, and supported by the singularly attractive potential. Its downfall is, of course, the fact that it doesn't work. :)

The Macintosh is Xerox technology at its best.