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NASA Still Trying to Verify Anti-Gravity Claims
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 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.
will finally get their flying car, perhaps from the german scientist? http://www.viewaskew.com/tv/leno/flyingcar.html
internet like monkeys'
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.
"less gravity is good for fat people"
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.
"Derp de derp."
Evgeny Podkletnov and Giovanni Modanese have posted one of their papers on the arXiv: http://xxx.lanl.gov/abs/physics/0108005
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.
If you were blocking sigs, you wouldn't have to read this.
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.
How we know is more important than what we know.
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.