Measuring tomorrow

Lynn Poole opens this program on man's ability to measure with a sample of the first standardized measurement, a cubit, used in building the pyramids. Dr. Allen Astin and his colleagues, from the U. S. National Bureau of Standards (NBS), discuss the four standards of measurement: length/meter, mass/kilogram, time/tropical year, and temperature/six points of Celsius. Dr. Astin also talks about direct measurement with a simple balance vs. indirect measurement with a proving ring or dynamometer. Dr. Robert Huntoon points out that the earth's rotation varies, so to determine the exact time, the NBS uses quartz crystals, or for more accuracy, ammonium atom vibration or a cesium clock operating on the forces within the cesium atom. The new accurate reference for measuring length is the mercury 198 lamp. In temperature standards, Dr. Herbert Broida notes that the Soviet Union is able to accurately measure extreme temperatures, which are important in the space race.