High vs Low Tc and Tajmar's Results
In this blog's posting of April 14, 2008, "Independent Support of Tajmar's Theory" reported that Tajmar's artificial gravity results appeared as temperatures approached that of low temperature (low-Tc) superconducting niobium. There was no such effect found for high-Tc superconductors composed of copper oxide compounds. Tajmar's study did not explain why there should be such a difference, but should different mechanisms underlying low and high Tc superconductors be found it would add weight to his findings.
Tajmar's theory depends upon the bosonic pairing of electrons known as "Coopers pairs". Cooper pairs also exist for high-Tc materials, yet the question has remained until now whether Coopers pairs form in the "pseudogap", that transition temperature just before high-Tc superconductivity. If found to form and if found to be based upon a mechanism different from low-Tc superconductivity it would bolster Tajmar's findings.
Today researchers have confirmed with new imaging techniques that electron pairs do emerge in the pseudogap but employ mechanisms very different from theories for conventional low-Tc superconductors such as niobium.
As quoted in this publication), "Together, the existence of preformed electron pairs... should help clarify the picture of high-Tc superconductivity, Brookhaven physicist Peter Johnson said. For example, the findings rule out some theories to explain the high-Tc phenomenon...", including certain "spin density wave" (SDW) and "charge density wave"(CDW) derived theories. Johnson's findings are consistent with competing theories such as "Mott insulators" and "charge stripes" that do not apply to low-Tc superconductors.
This further reinforces the distinctions between conventional low-Tc superconductors and high-Tc superconductors that Tajmar found.
©2008 Gregory Daigle