Word: decays
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Dates: during 1960-1969
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...surprisingly, one of the few jubilant scientists in Houston last week was Geochemist Oliver Schaeffer, who led the team that calculated the age of the lunar material. He used potassium-argon dating, a method based on the rate at which radioactive potassium decays into argon (it takes 1.3 billion years for half the potassium to decay); as time passes, the ratio between the potassium and argon in a specimen changes at a known rate, thus revealing the approximate age of the sample. If there is any error at all, Schaeffer explains, he has underestimated the age of the rocks, because...
...addition to the argon that resulted from potassium decay, Schaeffer found an abundance of solar argon-and of helium and neon-that has collected during eons of bombardment by the sun. These particles were lodged only in the surface of the rocks, where they had remained undisturbed for hundreds of millions of years-more evidence that the moon's exterior has not undergone any recent upheavals...
Chirps and Grunts. Reardon's voice, at any rate, shows no sign of decay, even though his repertory comprises 90 roles, 30 of them contemporary and 18 of them recerit premieres. In some ways, this versatility is as much a triumph of brain as of voice. "When word gets around that you can read something other than a C-major scale," he says, "people seem to pigeonhole you. I enjoy it, though. I'd go out of my mind if I sang nothing but Tosca and Traviata." Reardon pragmatically divides compositions into only two categories: music and nonmusic...
...week's end the infra-red spectrometer on board Mariner 7, the second of the two vehicles that flew past Mars, detected two gases-ammonia and methane-that could indicate the presence of primitive life. Both are produced on earth by biological decay. George C. Pimentel, a University of California chemist, said that he was unable to determine the amount of ammonia in the Martian atmosphere, but he estimated the concentration of methane as "no more than a few parts per million." In the earth's atmosphere, the amount is about 1.5 p.p.m.-and added rather jovially that...
With a love of cities that overshadows mere statistics, the author of The Death and Life of Great American Cities explores the financial aspects of growth and decay in urban centers...