Word: chemist
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...Chemist Libby's water clock will be based on the same principle as the carbon 14 calendar. Some ten miles high, in the stratosphere, cosmic rays stream in from outer space. With far more force than an atom-smasher, the cosmic rays collide with nitrogen atoms. The crash produces hydrogen, carbon 14 and a minute amount of radioactive tritium. The atoms of cosmic tritium join molecules of water vapor and fall to the earth in snow and rain...
Tritium has a half-life of 12½ years, i.e., half its radioactivity is dissipated in that time. "If our calculations are correct," says Chemist Libby, "then water 12½ years old should be only half as radioactive as new rainwater or snow...
When he has collected enough samples to calibrate his time clock, Chemist Libby will be able to answer some tough questions. Example: Is it true, as oceanographers believe, that there is no mixing of new water on the sea's surface and "old" brine below 700 feet...
...molecule is built up of hundreds or thousands of amino-acid-units which link together in complex ways. They form long chains, they branch, they tangle, they join together in rings. Even to identify the amino acids in a simple protein is a difficult task for the most skillful chemist. To figure how they are arranged in the protein molecule has baffled chemists completely. At last week's Second International Biochemistry Congress in Paris, Dr. Fred Sanger, 33, a Quaker chemist from Britain's Cambridge University, told how he and a group of associates had solved one protein...
...Chemist Sanger worked with crystalline insulin, a comparatively simple protein. First he broke the large molecules by oxidation into two fragments, one containing 21 amino-acid building blocks, the other 30. Then by other methods (e.g., hydrolysis), he broke the two parts down until he had fragments that contained only a few amino acids each. These were compounds familiar to biochemists. Sanger identified them by paper chromatography,† and the first and easiest part of his job was done...