29-APR-1893 :- BIRTH OF Harold Urey , Nobel Prize Winner .

Harold Clayton Urey 
(April 29, 1893 – January 5, 1981) was an American physical chemist whose pioneering work on isotopes earned him the Nobel Prize in Chemistry in 1934 for the discovery of deuterium. He played a significant role in the development of the atom bomb, but may be most prominent for his contribution to theories on the development of organic life from non-living matter.

Miller–Urey experiment

In later life, Urey helped develop the field of cosmochemistry and is credited with coining the term. His work on oxygen-18 led him to develop theories about the abundance of the chemical elements on earth, and of their abundance and evolution in the stars. Urey summarized his work in The Planets: Their Origin and Development (1952). Urey speculated that the early terrestrial atmosphere was probably composed of ammonia, methane, and hydrogen. One of his Chicago graduate students,Stanley L. Miller, showed in the Miller–Urey experiment that, if such a mixture be exposed to electric sparks and to water, it can interact to produce amino acids, commonly considered the building blocks of life.

Urey spent a year as a visiting professor at Oxford University in England in 1956 and 1957.In 1958, he reached the University of Chicago's retirement age of 65, but he accepted a post as a professor at large at the new University of California, San Diego (UCSD), and moved to La Jolla, California. He was subsequently made a professor emeritus there from 1970 to 1981.Urey helped build up the science faculty there. He was one of the founding members of UCSD's school of chemistry, which was created in 1960, along with Stanley Miller, Hans Suess, and Jim Arnold.

In the late 1950s and early 1960s, space science became a topical field of research in the wake of the launch of Sputnik I. Urey helped persuade NASA to make unmanned probes to a moon a priority. When Apollo 11 returned moon rock samples from the moon, Urey examined them at the Lunar Receiving Laboratory. The samples supported Urey's contention that the moon and the Earth shared a common origin. While at UCSD, Urey published 105 scientific papers, 47 of them about lunar topics. When asked why he continued to work so hard, he joked, "Well, you know I’m not on tenure anymore."