Defense Intelligence Reference Document The Role of Superconductors In Gravity Research

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permanent magnets), and a larger disk was spun at lower temperatures, the shielding
effect would be extremely small.
The experiment has remained controversial since its publication. Very few scientists put
any stock into it at all. Most damning to Podkletnov's case was the complete lack of any
supporting evidence that the experiment had ever actually taken place.
As the Podkletnov article began to slowly circulate, Li and Torr published another article
(Reference 18) expanding on their earlier investigations in an attempt to outline the
physical mechanism underlying the production of a gravitomagnetic field inside a
superconductor. Basic to their consideration was an assumption of near-zero magnetic
permeability in the superconductor and the requirement of coherent alignment of lattice
ion spins in conjunction with a time-varying applied magnetic vector potential field.
With this understanding, they determined values for laboratory-scale induced internal
gravitomagnetic fields and external gravitoelectric fields and how these fields could be
maximized. However, in 1994 Kowitt (Reference 26) claimed that their 1992 and 1993
results were not credible owing to their assumption of near-zero permeability inside a
superconductor. However, Li and Torr rather effectively countered shortly thereafter,
and Woods (Reference 3) also called that criticism into question. Later, however, Harris
(Reference 27) argued in a more effective critique that Li and Torr's previous results
were erroneous because they assumed arbitrary (and extremely small) distances from
the lattice ion to the observer, thus producing unreasonably large effects. In fact, Harris
pointed out that the correct estimation of the induced gravitoelectric field outside a
superconductor is some 20 orders of magnitude smaller! No evident rebuttal has been
forthcoming from Li or Torr.
At about this time, Torr and Li parted company, although both continued to work in the
area. In 1995, Li was sufficiently convinced that she now had the answer to producing
an artificial gravity field that could be measured outside a superconductor that she
approached R. Kaczor at NASA to fund further development of her version of the
theory. By this time the Podkletnov paper had been "discovered," and a few forward-
thinking NASA scientists determined that perhaps it was time to initiate some research
in the area. After all, now there was a peer-reviewed theoretical basis for a peer-
reviewed experiment. Also at this time, this author and colleagues began preliminary
experiments in Toronto after contacting Podkletnov. Our approach was to attempt to
reproduce the 1992 Physica C spinning disk experiment with additional data from
Podkletnov but using a better cryogenic design with the possibility of mechanically
spinning the disk. This author and colleagues started manufacturing our own large
YBCO disks in house.
The following year, while still at the Tampere University of Technology's Institute for
Materials Science, Podkletnov and Vuorinen attempted to publish updated spinning disk
experiments in the British Journal of Physics D Applied Phys Vol. 29 (1996), but the
paper was withdrawn in a cloud of controversy. It was later published on the Internet
(Reference 28) under the authorship of Podkletnov and Levit and then Podkletnov
alone. Vuorinen and Levit had coauthored papers on ceramic processing with
Podkletnov previously. This new experiment involved a large AC levitated 27-cm-
diameter bi-layer sintered YBCO disk spun to 5,000 rpm using two-phase high-
frequency radiofrequency (RF) "rotation" fields and allegedly showed gravitational
shielding in the few percent range. The cryostat design was somewhat better in that
there was considerably more shielding of the test mass from buoyancy and thermal
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