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.
MicroGravity is Your Friend (Score:4, Interesting)
Wired magazine article (Score:4, Interesting)
Re:Getting Dizzy... (Score:2, Interesting)
I've also got a stupid joke:
Future hard drive technology may allow super-lightweight Linux distributions.
Re:Interesting but... (Score:3, Interesting)
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.
AntiGravy (Score:3, Interesting)
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)
Re:less gravity is good for fat people (Score:5, Interesting)
I had the same reaction to this comment that I did when an 80 year old man was found dead on an airplane the other day. There was some debate as to whether or not he died before he got on the plane, or after.
One of the officials said "I'm pretty sure we wouldn't have allowed a dead man to board a plane." (true story)
In any case, lower gravity would help obese people move around more, but in the long term it wouldn't be such a good idea. The problem is that it'd make their condition worse as they'd be burning less energy trying to walk.
I realize you were probably just being silly, but it got me thinking. Lets say one day we had gravity reduction devices in our home to make us more comfy. Would that lead to a weaker speices down the road? Some would see the mass production of cars to have had a similar effect on our species.
The thought of gravity reduction devices scares me a little, although their applicates would definitely change the world we live in.
Levitation Movies on ArtBell.com (Score:1, Interesting)
Created by odd people, which is why Art Bell has their footage on his goofy site, but check out this link [artbell.com] and look for the levitation videos, which are actually at the following (links directly to movies on art bell's site):
Movie 1 [artbell.com]
Movie 2 [artbell.com]
I think these were made by the guys who published that paper on stove top fusion a few years back... these are actual, though goofy, movies of alleged (and highly dubious) levitation.
Silly? You bet. Also on that art bell page are links to movies with David Blain street magic levitation tricks. Anti-gravity-like stuff.
Re:why this got funded... (Score:1, Interesting)
Re:Not the first $600K NASA dumped down this ratho (Score:2, Interesting)
I'm sorry, run that by me again? If they succeed at reducing the gravitational mass of an object but it requires expenditure of energy, you'd consider that a "null result"? I suppose next thing you are going to tell me is that electrostatic repulsion doesn't exist because moving the charges to measure it requires expenditure of energy.
2.6 Million bucks is a lot of money. It can fund many, many, many more real projects. Instead, it gone thrown into an unsubstantiated, non-peer-reviewed crackpottery by a guy who refuses to reveal the details of his so-called experiment.
Frankly, given the kind of uninspired, peer-reviewed, publicity-hungry junk I come across daily, I'm glad to see that some people are still spending money on long-shots and crackpots. If science were exclusively done by what one's peers think useful or interesting, we'd still be living in the stone age. I think this particular experiment is a long-shot, and after $2.6M it may really be time to start looking elsewhere. But, then, I think it's much less of a long-shot than the kind of nonsense theorists have been engaging in.
And it's not like the idea that there is something funny going on with gravity were completely unfounded. We know that Einstein's theory disagrees grossly with what we observe. It's not a question of if we can replicate this experimentally but how.
Re:Not the first $600K NASA dumped down this ratho (Score:4, Interesting)
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.
Re:Gravitational vs. Inertial Mass (Score:2, Interesting)
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
Re:Not the first $600K NASA dumped down this ratho (Score:3, Interesting)
OK, disclaimer here: Note that I said "GR", not "Newtonian" gravity - yes, I know that every textbook on the planet says that GR agrees with Mercury's orbit "phenomenally well" - but it's not really true. If you check out a decent astrophysics textbook (I -think- it's in Carroll & Ostlie) there were findings in the early 90s (I think... I'll try to look it up, but I figured I'd post this first so more people'll look around) that the discrepancies in Mercury's orbit could be mostly explained away due to non-sphericity of the Sun. When you take that into account, GR doesn't agree quite so well (unless someone's cleaned this up recently, which is possible. No one seems to care, actually).
That said, that wasn't what the poster was talking about - my guess is that the original poster was talking about stuff like continuous spacetime vs. quantum spacetime, but again, that's quantum effects.
I'm still of the opinion that the anomalous mass changes above a superconductor COULD be real (and could be quantum, keep in mind that superconductors produce weird quantum states of electrons) - after all, before people knew about the Casimir effect, no one would ever have thought to claim that sticking two pieces of metal very very close to each other would cause them to be strongly attracted to each other by anything except gravity.
That being said, I think it's probably experimental error, and I REALLY don't appreciate the way the original scientist handled it. The fact that he hid his experimental setup (or the complete details of it) out of fear of someone stealing his idea is such crap. Personally, if it had been me, I wouldn't've cared. If it does work, it's such a revolutionary breakthrough that I wouldn't've even cared about the economic benefits to me - the scientific benefits are too massive (besides, SOMEONE would've named the effect after me - or me and someone else - and that's all I really care about
Re:Forget Antigravity, how about a Gravity device? (Score:4, Interesting)
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!)
Mmmmm.... spinning disks... (Score:3, Interesting)
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.
Superconductor and Anti-magnetism (Score:2, Interesting)
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.
Re:Gravitational vs. Inertial Mass (Score:2, Interesting)
Re:Gravitational vs. Inertial Mass (Score:3, Interesting)
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
Re:Gravitational vs. Inertial Mass (Score:3, Interesting)
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.
Coral Castle (Score:2, Interesting)
There are plenty of places on the internet to read about Coral Castle, but here's the jist of it. Edward Leedskalnin, a small Latvian man, built Coral Castle by hand. It's pretty much a garden with many different celestial-style arrangements and setups built with carved coral. Many of the pieces are over 10 tons in weight, and the entire place was built by Ed entirely by hand and by himself. He worked only in private, but claimed to have found the secret to how the Egyptians built the Great Pyramids.
When I was at Coral Castle, I learned that when Ed died some people from the government came and seized some of Ed's things, claiming that they were a threat to national security. Judging by the experiments NASA is trying, I'm sure they're based partly on some of the things that Ed did with coral.
Interesting Intellectual Experiment (Score:3, Interesting)
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//
Re:Gravitational vs. Inertial Mass (Score:2, Interesting)
I can still argue that your field-theoretical argument for gravity is a little odd since the tensor field is just an ad-hoc stand-in to reproduce GR in a certain (albeit reasonable) regime. If there were an independant reason to believe the field theory explanation of gravity, then it would be a different story.
I can also appreciate the line of reasoning that this antigrav research isn't completely unjustified. It's relatively low-cost I'm sure. But I have a hard time figuring out why they are reproducing Podkletnov's exact experiment instead of just putting together another random assemblage of cool devices. I would give his claims exactly zero credit until there is some reason to believe that he did his work carefully and honestly. On the other hand, there's no reason to build anything different, either.
One problem with his experiment is that it's complicated enough to make it hard to rule out the "usual suspects" (E&M effects) if any anti-grav-like effect is observed. Building the device and making the measurements sounds relatively easy, but interpreting the results could be nearly impossible. Well, at least it'll keep people busy.
- Topher