Ginisiluwa January 01 | Page 143

Superconductivity Year of Discovery: 1911 What Is It? Some materials lose all resistance to electrical current at super-low temperatures. Who Discovered It? Heike Kamerlingh Onnes Why Is This One of the 100 Greatest? Superconductivity is the flow of electrical current without any resistance to that flow. Even the best conductors have some resistance to electrical current. But superconductors do not. Unfortunately, superconductors only exist in the extreme cold of near absolute zero. Even though the practical application of this discovery has not yet been realized, superconductivity holds the promise of super-efficient electrical and magnetic motors, of electrical current flowing thousands of miles with no loss of power, and of meeting the dream of cheap and efficient electricity for everyone. Superconductivity will likely spawn whole new industries and ways of generating, processing, and moving electrical energy. But that potential still lies in the future. How Was It Discovered? Heike Onnes was born in 1853 in Groningen, the Netherlands, into a wealthy family that owned a brick making factory. As he went through college and graduate school, he drew considerable attention for his talent at solving scientific problems. By the time he was 18, Onnes had become a firm believer in the value of physical experimentations and tended to discount theories that could not be demonstrated by physical experiment. At the age of 25, Onnes focused his university research on the properties of materials at temperatures approaching the coldest possible temperature (-456°F or -269°C). The existence of that temperature, the temperature at which all heat energy is gone and all motion —even inside an atom—ceases, was discovered by Lord Kelvin, and is called 0° Kelvin (0°K) or absolute zero. Several theories existed about what happened near 0°K. ??&B?V?f??&V?WfVBF?B'6??WFR?W&?v?V?B7F?F?R??F????bV?V7G&??2?V?V7G&?6?7W'&V?Bv?V?B6V6R?B&W6?7F?6RF?F?B7W'&V?Bv?V?B&R??f???FV??&vR??F?W'2&V?WfVBF?R??6?F^( GF?B&W6?7F?6P?v?V?Bf??F??W&??BV?V7G&?6?7W'&V?G2v?V?Bf??rf?&WfW"??WfW'???R?BF?V?'?????W2FV6?FVBF?f??B?WB?F?FW7BF?RF?V?&?W2?#????