Willard libby radiocarbon dating etichetta discografica online dating
He became well-known at University of Chicago for his work on natural carbon-14 (radiocarbon) and its use in dating archaeological artifacts, and natural tritium, and its use in hydrology and geophysics.
Besides the Nobel Prize in Chemistry for 1960, he received other distinctions, including the Research Corporation Award for 1951 for the radiocarbon dating technique; the Chandler Medal of Columbia University for outstanding achievement in the field of chemistry (1954); the American Chemical Society Award for Nuclear Applications in Chemistry (1956); the Elliott Cresson Medal of the Franklin Institute (1957); the American Chemical Society's Willard Gibbs Medal Award (1958); the Albert Einstein Medal Award (1959); the Day Medal of the Geological Society of America (1961).
Professor Willard Libby has been selected to be the prize-winner for his method of age determination of materials of biological origin by use of carbon-14 as a measurer of time.
His method has obtained widespread use and has become indispensable in archaeology, geology, geophysics and other sciences.
In about one million million of these carbon atoms, there is only one which has an atomic weight of 14.
But nevertheless, this ratio can be determined, for carbon-14 is a radioactive isotope and manifests itself by its radiation.
Because the activity of the carbon atoms decreases at a known rate, it should be possible, by measuring the remaining activity, to determine the time elapsed since death, if this occurred during the period between approximatively 500 and 30,000 years ago.
This hypothesis was published by Libby in 1947, and with his great experimental skill it did not take him long to prove the validity of the theory.
The disintegration is such a slow procedure, however, that 5,600 years are required to convert half of these atoms into nitrogen. He was awarded a Guggenheim Memorial Foundation Fellowship in 1941 and elected to work at Princeton University, but on 8th December, 1941, this Fellowship was interrupted for war work on America's entry into World War II, and Libby went to Columbia University on the Manhattan District Project, on leave from the Department of Chemistry, California University, till 1945. This appointment was renewed by the President for a further five-year term on 19th June, 1956, but Libby resigned from it on 30th June, 1959, to become Professor of Chemistry in the University of California at Los Angeles, being appointed Director of the Institute of Geophysics and Planetary Physics on 1st January, 1962. He was appointed Instructor in the Department of Chemistry at California University (Berkeley) in 1933 and during the next ten years was promoted successively to Assistant and then Associate Professor of Chemistry.Recently dead biological substances, such as wood and plant materials, seal oil and others, showed an activity which could the calculated from the knowledge of the production of carbon-14 in the atmosphere, and its rate of decomposition.Fossil material, such as petroleum, was completely inactive; it comes from organisms which lived millions of years ago.
He is married to the former Leonor Hickey of King City, California. It was later edited and republished in Nobel Lectures.