What's up with spinning superconductors?

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Not a shield, a spinning mass generates a gravitational field.
AFAIK any mass should work - the superconductor is just experimental convenience.

Legit researchers at a legit institution and there is every reason to suspect that GR isn't quite correct at quantum scales.
 
The claims on TV that I saw were even more fantastic.

They said that a spinning superconductor reduces the gravitational field above them! It was visible with even blowing smoke over the apparatus. Apparently it only worked with superconductors and people had troubles reproducing the results, since it was tough to get a large enough superconductor spin fast enough.
How to think about that?
 
Gerenuk said:
How serious is this to be taken?
I'd say not at all. Podkletnov's 'antigravity' claims have never been duplicated and he's squarely in the "fringe science" camp and thus beyond the scope of PF.
 
Regarding the Tajmar results of 2006 (which is what the OP's link directly referred to), I could not find any published results, only a preprint from 2006. (http://arxiv.org/abs/gr-qc/0603033) If the work was published in the mainstream press, PM me and I'll reopen this thread.
 
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From $$0 = \delta(g^{\alpha\mu}g_{\mu\nu}) = g^{\alpha\mu} \delta g_{\mu\nu} + g_{\mu\nu} \delta g^{\alpha\mu}$$ we have $$g^{\alpha\mu} \delta g_{\mu\nu} = -g_{\mu\nu} \delta g^{\alpha\mu} \,\, . $$ Multiply both sides by ##g_{\alpha\beta}## to get $$\delta g_{\beta\nu} = -g_{\alpha\beta} g_{\mu\nu} \delta g^{\alpha\mu} \qquad(*)$$ (This is Dirac's eq. (26.9) in "GTR".) On the other hand, the variation ##\delta g^{\alpha\mu} = \bar{g}^{\alpha\mu} - g^{\alpha\mu}## should be a tensor...

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