Word: cobalt
(lookup in dictionary)
(lookup stats)
Dates: all
Sort By: most recent first
(reverse)
...Chilled Cobalt. In brilliantly reasoned papers Lee and Yang showed that it should be possible to get along without parity. They also suggested ways to test experimentally whether parity is really a basic principle of nature. By this time the whole world of theoretical physics was watching Lee and Yang, and the best facilities in the U.S. were offered for testing their theory...
Another Chinese physicist at Columbia, Associate Professor Chien-Shiung Wu, went to Washington. Working with a topflight team at the National Bureau of Standards, she arranged an elaborate deepfreeze apparatus to cool radioactive cobalt 60 to 0.01° above absolute zero ( - 273.1° C.). The cobalt nuclei are known to be spinning, and they continue to spin in the deepfreeze, but their random "thermal" motions are reduced almost to nothing by the extreme cold. This accomplished. Dr. Wu and her helpers applied a powerful magnetic field that pointed the cobalt nuclei in one direction as if they were tiny magnets...
Temperature has no effect on radioactivity, so the chilled, lined-up cobalt atoms went right on disintegrating and emitting electrons. According to the parity principle, the electrons should shoot off in equal numbers in both directions along the spin axes of the lined-up nuclei. Any preference by the electrons for either direction would prove that parity is not a real law of nature...
Chinese Lunch. The chilled cobalt experiment proved extremely difficult, but by last fortnight Dr. Wu reported her results. The electrons were not shooting off equally in both directions. This looked bad for parity, and spirits rose high in the anti-parity camp...
...adoption of the Gorman joint. But he has high hopes for it. Moving parts are metal against metal, lubricated by body fluids, so no foreign material is in moving contact with human tissue (which has caused trouble in some earlier plastic and metal restorations). Made of Stellite (a chromium-cobalt alloy), the joint should outlast the life of the recipient, with no corrosion...