Defense Intelligence Reference Document The Role of Superconductors In Gravity Research

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would be required to explain the mass anomaly, a field that may be investigated in the
laboratory. In fact, he proposed an experiment "measuring the torque on a spinning
gyroscope produced by the gravitomagnetic field possibly generated by rotating
superconductors." His subsequent publications showed that he was convinced that the
"anomalous gravitomagnetic London moment" can actually be detected in the lab and
noted that an experiment was already underway under his direction.
In an attempt to bring some order to the discussion about correct laboratory practices
in experiments designed to detect gravity-like forces, Reiss and Hathaway (Reference
43) collaborated on a paper published in 2005. They tried to remind experimentalists
about the perils and pitfalls in the kind of research documented in the present paper.
This author meanwhile presented an extensive list of experimental issues that is
available and is still being added to on the Internet (Reference 9). These issues range
from spurious mechanical effects to electromagnetic and electrostatic effects together
with a discussion of signal analysis and instrumentation issues.
The following year, Tajmar et al. (Reference 44) described the results of an experiment
they had performed to try to validate their conclusions about the anomalous London
moment, which they termed the "gravitomagnetic London moment." The experiment
involved spinning niobium and high-temperature ceramic superconductor rings at LHe
temperatures. No external magnetic fields were applied. They claimed to have found
the expected large gravitomagnetic field as detected by nearby accelerometers that
matched to within a factor of 1.5 of their theoretical results. Eric Davis at the Institute
for Advances Studies in Austin has raised concerns about the theoretical basis for the
claim. Davis contends (Reference 45) that the basis for calculating the Cooper pair
mass is still so fraught with uncertainties as to leave Tajmar's mass anomaly
unfounded. This leaves the theoretical basis of Tajmar's experiment in some doubt.
There were also several concerns about the experimental design and protocol.
By 2007, Tajmar (Reference 46) recognized that new data from improved experiments
did not match their prior predictions. Nevertheless, an unexplained residual signal
persisted that exhibited several unexpected features, including a relatively large
coupling constant of 10-s between the observed acceleration effect and the applied
angular velocity. The effect appears to be proportional to angular momentum and
inversely proportional to temperature after passing a critical temperature (which is
dependent on the material of the spinning ring and is not coincident with the
superconducting critical temperature). In addition, the effect is more pronounced in the
clockwise rotation direction (as viewed from above), and it does not decay as a dipole
field would. While Tajmar et al. endeavor to address all possible systematic errors or
prosaic explanations, they conclude that the "measurements rule out our previous
theoretical model that predicted a coupling proportional to the material's Cooper pair
and lattice mass density." The residual signal observed in the most recent experiments
remains unexplained.
After Tajmar et al. considered improvements to the apparatus suggested by other
researchers, Tajmar's effect continued to approach the noise floor. Unfortunately, the
explanations Tajmar provided in 2008 (Reference 47) for the residual effects became
more difficult to understand and believe. It is not known whether Taj mar is continuing
the experimentation at present.
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