AT&T Co’s Bell Laboratories has made another potentially invaluable discovery about high temperature superconductors using extremely pure crystals of a ceramic of Bismuth, Strontium, Calcium, Copper and Oxygen, they found that resistance rose as the amount of current being passed increased: coupling this piece of information with the fact that resistance rises catastrophically at a given current level in superconducting ceramics containing impurities and crystal defects (thereby providing the potential for creating analogue switches, but that’s another story), it is thought that researchers may be a step or two nearer determining which dopants to use to maximise the superconductivity of the ceramic at a desired high temperature.