## 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.
## less gravity is good for fat people (Score:1, Informative)

## Not the first $600K NASA dumped down this rathole (Score:5, Informative)

## Re:Interesting but... (Score:3, Informative)

## Re:Interesting but... (Score:2, Informative)

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.

## Re:Poor Article Poor chances (Score:4, Informative)

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

## Re:Poor Article Poor chances (Score:4, Informative)

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

everythingto do with mass. Gravity is the attraction of objects to each other because of theirmass. 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)

"..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)

## podkletnov's paper (Score:5, Informative)

## Why its not antigravity.. (Score:3, Informative)

## Gravitational vs. Inertial Mass (Score:4, Informative)

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

## Tying In The Higgs Boson (Score:3, Informative)

## hmmm (Score:2, Informative)

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).

## Re:Forget Antigravity, how about a Gravity device? (Score:5, Informative)

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.

## Re:Gravitational vs. Inertial Mass (Score:3, Informative)

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.

Electromagnetism:

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)

Gravity:

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.