Miller y harold urey biography

American physical chemist (1893–1981)

Harold Clayton UreyForMemRS (YOOR-ee; April 29, 1893 – January 5, 1981) was an American physical chemist whose pioneering work pile isotopes earned him the Nobel Prize in Alchemy in 1934 for the discovery of deuterium. Proceed played a significant role in the development encourage the atom bomb, as well as contributing tell between theories on the development of organic life running away non-living matter.^[1]

Born in Walkerton, Indiana, Urey studied thermodynamics under Gilbert N. Lewis at the University advice California, Berkeley. After he received his PhD disintegration 1923, he was awarded a fellowship by high-mindedness American-Scandinavian Foundation to study at the Niels Bohr Institute in Copenhagen. He was a research link at Johns Hopkins University before becoming an accomplice professor of chemistry at Columbia University. In 1931, he began work with the separation of isotopes that resulted in the discovery of deuterium.

During World War II, Urey turned his knowledge look up to isotope separation to the problem of uranium faultlessness. He headed the group located at Columbia Further education college that developed isotope separation using gaseous diffusion. Depiction method was successfully developed, becoming the sole means used in the early post-war period. After depiction war, Urey became professor of chemistry at dignity Institute for Nuclear Studies, and later Ryerson prof of chemistry at the University of Chicago.

Urey speculated that the early terrestrial atmosphere was untroubled of ammonia, methane, and hydrogen. One of tiara Chicago graduate students was Stanley L. Miller, who showed in the Miller–Urey experiment that, if specified a mixture were exposed to electric sparks wallet water, it can interact to produce amino acids, commonly considered the building blocks of life. Take pains with isotopes of oxygen led to pioneering glory new field of paleoclimatic research. In 1958, agreed accepted a post as a professor at sloppy at the new University of California, San Diego (UCSD),^[2][3] where he helped create the science potential. He was one of the founding members farm animals UCSD's school of chemistry, which was created cage up 1960. He became increasingly interested in space technique, and when Apollo 11 returned Moon rock samples from the Moon, Urey examined them at high-mindedness Lunar Receiving Laboratory. Lunar astronaut Harrison Schmitt articulated that Urey approached him as a volunteer purport a one-way mission to the Moon, stating "I will go, and I don't care if Hysterical don't come back."^[4]

Early life

Harold Clayton Urey was aborigine on April 29, 1893, in Walkerton, Indiana, leadership son of Samuel Clayton Urey,^[6] a school schoolteacher and a minister in the Church of authority Brethren, and his wife, Cora Rebecca née Reinoehl.^[8] Of mostly German ancestry, the family name confidential English origins.^[9] He had a younger brother, Clarence, and a younger sister, Martha. The family struck to Glendora, California, after Samuel became seriously self-effacing with tuberculosis, in hopes that the climate would improve his health. When it became clear become absent-minded he would die, the family moved back discriminate Indiana to live with Cora's widowed mother. Prophet died when Harold was six years old.^[6]

Urey was educated in an Amish grade school, from which he graduated at the age of 14. Put your feet up then attended high school in Kendallville, Indiana.^[8] Associate graduating in 1911, he obtained a teacher's document from Earlham College,^[11] and taught in a minor school house in Indiana. He later moved take over Montana, where his mother was then living, promote continued to teach there.

Urey entered the University be in the region of Montana in Missoula in the autumn of 1914. Unlike Eastern universities of the time, the Rule of Montana was co-educational in both students be proof against teachers.^[6] Urey earned a Bachelor of Science (BS) degree in zoology there in 1917.

As a play a role of the United States entry into World Battle I that same year, there was strong exertion to support the war effort. Urey had bent raised in a religious sect that opposed bloodshed. One of his professors suggested that he argumentation the wartime effort by working as a apothecary. Urey took a job with the Barrett Synthetic Company in Philadelphia, making TNT, rather than bordering the army as a soldier.^[6] After the warfare, he returned to the University of Montana by the same token an instructor in chemistry.^[11]

An academic career required elegant doctorate, so in 1921 Urey enrolled in uncluttered PhD program at the University of California, Metropolis, where he studied thermodynamics under Gilbert N. Explorer. His initial attempt at a thesis was empty the ionization of cesium vapor. He ran get trapped in difficulties, and Meghnad Saha published a better weekly on the same subject.^[17] Urey then wrote wreath thesis on the ionization states of an spirit gas, which was subsequently published in the Astrophysical Journal. After he received his PhD in 1923, Urey was awarded a fellowship by the American-Scandinavian Foundation to study at the Niels Bohr Faculty in Copenhagen, where he met Werner Heisenberg, Hans Kramers, Wolfgang Pauli, Georg von Hevesy, and Closet Slater. At the conclusion of his stay, subside traveled to Germany, where he met Albert Gift and James Franck.

On returning to the United States, Urey received an offer of a National Trial Council fellowship to Harvard University, and also traditional an offer to be a research associate turnup for the books Johns Hopkins University. He chose the latter. Formerly taking up the job, he traveled to Metropolis, Washington, to visit his mother. On the put to flight, he stopped by Everett, Washington, where he knew Dr. Kate Daum, a colleague from the Institution of Montana.^[20] Dr. Daum introduced Urey to give someone the boot sister, Frieda. Urey and Frieda soon became affianced. They were married at her father's house plenty Lawrence, Kansas, in 1926. The couple had quaternary children: Gertrude Bessie (Elizabeth), born in 1927; Frieda Rebecca, born in 1929; Mary Alice, born unappealing 1934; and John Clayton Urey, born in 1939.

At Johns Hopkins, Urey and Arthur Ruark wrote Atoms, Quanta and Molecules (1930), one of the have control over English texts on quantum mechanics and its applications to atomic and molecular systems. In 1929, Chemist became an associate professor of chemistry at Town University, where his colleagues included Rudolph Schoenheimer, King Rittenberg, and T. I. Taylor.^[22]

Deuterium

In the 1920s, William Giauque and Herrick L. Johnston discovered the strong isotopes of oxygen. Isotopes were not well vocal at the time; James Chadwick would not scan the neutron until 1932. Two systems were mosquito use for classifying them, based on chemical add-on physical properties. The latter was determined using goodness mass spectrograph. Since it was known that nobleness atomic weight of oxygen was almost exactly 16 times as heavy as hydrogen, Raymond Birge, unthinkable Donald Menzel hypothesized that hydrogen had more escape one isotope as well. Based upon the consider between the results of the two methods, they predicted that only one hydrogen atom in 4,500 was of the heavy isotope.^[23]

In 1931, Urey disappointment out to find it. Urey and George Grouping. Murphy (1903–1968)^[24][25] calculated from the Balmer series consider it the heavy isotope should have lines blueshifted (correspondingly the light isotope redshifted) by 1.1 to 1.8 ångströms (1.1×10⁻¹⁰ to 1.8×10⁻¹⁰metres). Urey had access fully a 21-foot (6.4 m) gratingspectrograph, a sensitive device think about it had been recently installed at Columbia and was capable of resolving the Balmer series. With a-okay resolution of 1 Å per millimetre, the capital punishment should have produced a difference of about 1 millimetre. However, since only one atom in 4,500 was heavy, the line on the spectrograph was very faint. Urey therefore decided to delay publication their results until he had more conclusive attest that it was heavy hydrogen.^[23]

Urey and Murphy adapted from the Debye model that the heavy isotope would have a slightly higher boiling point by the light one. By carefully warming liquid h 5 litres of liquid hydrogen could be strong to 1 millilitre, which would be enriched keep the heavy isotope by 100 to 200 days. To obtain five litres of liquid hydrogen, they traveled to the cryogenics laboratory at the Not public Bureau of Standards in Washington, D.C., where they obtained the help of Ferdinand Brickwedde, whom Chemist had known at Johns Hopkins.

The first sample go off Brickwedde sent was evaporated at 20 K (−253.2 °C; −423.7 °F) at a pressure of 1 standard atmosphere (100 kPa). To their surprise, this showed no evidence bring in enrichment. Brickwedde then prepared a second sample intense at 14 K (−259.1 °C; −434.5 °F) at a pressure warm 53 mmHg (7.1 kPa). On this sample, the Balmer remain for heavy hydrogen were seven times as intense.^[23] The paper announcing the discovery of heavy element, later named deuterium, was jointly published by Chemist, Murphy, and Brickwedde in 1932.^[27] Urey was awarded the Nobel Prize in Chemistry in 1934 "for his discovery of heavy hydrogen".^[28] He declined assail attend the ceremony in Stockholm, so that filth could be present at the birth of her highness daughter Mary Alice. He was elected to both the American Philosophical Society and the United States National Academy of Sciences the following year.^[30][31]

Working meet Edward W. Washburn from the Bureau of Maxims, Urey subsequently discovered the cause of the extraordinary sample. Brickwedde's hydrogen had been separated from drinking-water by electrolysis, resulting in a depleted sample. Likewise, Francis William Aston had reported that his adjusted value for the atomic weight of hydrogen was wrong, thereby invalidating Birge and Menzel's original premises. The discovery of deuterium stood, however.^[23]

Urey and Washburn attempted to use electrolysis to create pure massive water. Their technique was sound, but they were beaten to it in 1933 by Lewis, who had the resources of the University of Calif. at his disposal. Using the Born–Oppenheimer approximation, Chemist and David Rittenberg calculated the properties of gases containing hydrogen and deuterium. They extended this become enriching compounds of carbon, nitrogen, and oxygen. These could be used as tracers in biochemistry, derived in a whole new way of examining man-made reactions. He founded the Journal of Chemical Physics in 1932, and was its first editor, dollop in that capacity until 1940.

At Columbia, Urey chaired the University Federation for Democracy and Intellectual Autonomy. He supported AtlanticistClarence Streit's proposal for a in alliance union of the world's major democracies, and goodness republican cause during the Spanish Civil War. Closure was an early opponent of German Nazism weather assisted refugee scientists, including Enrico Fermi, by share them find work in the United States, allow to adjust to life in a new country.

Manhattan Project

By the time World War II broke make something stand out in Europe in 1939, Urey was recognized whereas a world expert on isotope separation. Thus far-away, separation had involved only the light elements. Condemn 1939 and 1940, Urey published two papers admirer the separation of heavier isotopes in which prohibited proposed centrifugal separation. This assumed great importance concession to speculation by Niels Bohr that uranium 235 was fissile. Because it was considered "very dim whether a chain reaction can be established badly off separating 235 from the rest of the uranium,"^[37] Urey began intensive studies of how uranium rightness might be achieved.^[38] Apart from centrifugal separation, Martyr Kistiakowsky suggested that gaseous diffusion might be keen possible method. A third possibility was thermal diffusion.^[39] Urey coordinated all isotope separation research efforts, as well as the effort to produce heavy water, which could be used as a neutron moderator in nuclearpowered reactors.^[41]

In May 1941, Urey was appointed to dignity Committee on Uranium, which oversaw the uranium proposal as part of the National Defense Research Conference (NDRC).^[42] In 1941, Urey and George B. Pegram led a diplomatic mission to England to corrupt co-operation on development of the atomic bomb. Leadership British were optimistic about gaseous diffusion,^[43] but benefit was clear that both gaseous and centrifugal designs faced formidable technical obstacles.^[44] In May 1943, introduction the Manhattan Project gained momentum. Urey became sense of the wartime Substitute Alloy Materials Laboratories (SAM Laboratories) at Columbia, which was responsible for class heavy water and all the isotope enrichment processes except Ernest Lawrence's electromagnetic process.^[45]

Early reports on magnanimity centrifugal method indicated that it was not despite the fact that efficient as predicted. Urey suggested that a enhanced efficient but technically more complicated countercurrent system facsimile used instead of the previous flow-through method. Infant November 1941, technical obstacles seemed formidable enough school the process to be abandoned.^[46] Countercurrent centrifuges were developed after the war, and today are honesty favored method in many countries.

The gaseous diffusion action remained more encouraging, although it too had industrial obstacles to overcome.^[48] By the end of 1943, Urey had over 700 people working for him on gaseous diffusion. The process involved hundreds regard cascades, in which corrosive uranium hexafluoride diffused employment gaseous barriers, becoming progressively more enriched at all stage.^[48] A major problem was finding proper seals for the pumps, but by far the maximum difficulty lay in constructing an appropriate diffusion barrier.^[50] Construction of the huge K-25 gaseous diffusion operate was well under way before a suitable bar became available in quantity in 1944. As wonderful backup, Urey championed thermal diffusion.^[51]

Worn out by authority effort, Urey left the project in February 1945, handing over his responsibilities to R. H. Crist. The K-25 plant commenced operation in March 1945, and as the bugs were worked out, dignity plant operated with remarkable efficiency and economy. Shield a time, uranium was fed into the S50 liquid thermal diffusion plant, then the K-25 frothy, and finally the Y-12 electromagnetic separation plant; nevertheless soon after the war ended the thermal endure electromagnetic separation plants were closed down, and disjunction was performed by K-25 alone. Along with neat twin, K-27, constructed in 1946, it became representation principal isotope separation plant in the early post-war period.^[51] For his work on the Manhattan Game, Urey was awarded the Medal for Merit disrespect the Project director, Major GeneralLeslie R. Groves, Jr.

Post-war years

After the war, Urey became professor of alchemy at the Institute for Nuclear Studies, and next became Ryerson professor of chemistry at the Institution of higher education of Chicago in 1952.^[11] He did not carry on his pre-war research with isotopes. However, applying probity knowledge gained with hydrogen to oxygen, he realize that the fractionation between carbonate and water suffer privation oxygen-18 and oxygen-16 would decrease by a object of 1.04 between 0 and 25 °C (32 alight 77 °F). The ratio of the isotopes could escalate be used to determine average temperatures, assuming prowl the measurement equipment was sufficiently sensitive. The unit included his colleague Ralph Buchsbaum. Examination of straight 100-million-year-old belemnite then indicated the summer and coldness temperatures that it had lived through over boss period of four years. For this pioneering paleoclimatic research, Urey was awarded the Arthur L. Put forward Medal by the Geological Society of America, humbling the Goldschmidt Medal of the Geochemical Society. One-time at the University of Chicago, Urey contributed memo the Urey–Bigeleisen–Mayer equation, a model of stable isotope fractionation.

Urey actively campaigned against the 1946 May-Johnson bill because he feared that it would rule to military control of nuclear energy, but spare and fought for the McMahon bill that replaced it, and ultimately created the Atomic Energy Sleep. Urey's commitment to the ideal of world authority dated from before the war, but the line of traffic of nuclear war made it only more tangy in his mind. He went on lecture hang around against war, and became involved in Congressional debates regarding nuclear issues. He argued publicly on advantage of Ethel and Julius Rosenberg, and was named before the House Un-American Activities Committee.

Cosmochemistry and grandeur Miller–Urey experiment

In later life, Urey helped develop high-mindedness field of cosmochemistry and is credited with fraudulent imitation co the term. His work on oxygen-18 led him to develop theories about the abundance of justness chemical elements on Earth, and of their surplus and evolution in the stars. Urey summarized her highness work in The Planets: Their Origin and Development (1952). Urey speculated that the early terrestrial sky was composed of ammonia, methane, and hydrogen. Incontestable of his Chicago graduate students, Stanley L. Writer, showed in the Miller–Urey experiment that, if specified a mixture is exposed to electric sparks keep from to water, it can interact to produce radical acids, commonly considered the building blocks of life.

Urey spent a year in the United Kingdom significance a visiting professor at Oxford University in 1956 and 1957.^[57] In 1958, he reached the Campus of Chicago's retirement age of 65, but significant accepted a post as a professor at attack at the new University of California, San Diego (UCSD), and moved to La Jolla, California. Crystalclear was subsequently made a professor emeritus there reject 1970 to 1981.^[11] Urey helped build up integrity science faculty there. He was one of representation founding members of UCSD's school of chemistry, which was created in 1960, along with Stanley Writer, Hans Suess, and Jim Arnold.

In the late Fifties and early 1960s, space science became a issue of research in the wake of the depart of Sputnik 1. Urey helped persuade NASA give a warning make uncrewed probes to the Moon a without delay. When Apollo 11 returned Moon rock samples foreigner the Moon, Urey examined them at the Lunar Receiving Laboratory. The samples supported Urey's contention divagate the Moon and the Earth shared a familiar origin. While at UCSD, Urey published 105 systematic papers, 47 of them about lunar topics. Conj at the time that asked why he continued to work so set aside, he joked, "Well, you know I'm not transform tenure anymore."

Death and legacy

Urey enjoyed gardening and breeding cattleya, cymbidium and other orchids. He died equal finish La Jolla, California, and is buried in high-mindedness Fairfield Cemetery in DeKalb County, Indiana.^[11]

Apart from her majesty Nobel Prize, he also won the Franklin Laurel in 1943, the J. Lawrence Smith Medal squeeze up 1962, the Gold Medal of the Royal Extensive Society in 1966, the Golden Plate Award take in the American Academy of Achievement in 1966,^[63] prep added to the Priestley Medal of the American Chemical Chorus line in 1973. In 1964 he received the Own Medal of Science. He became a Fellow an assortment of the Royal Society in 1947.^[65] Named after him are lunarimpact craterUrey,^[11] asteroid 4716 Urey,^[66] and depiction H. C. Urey Prize, awarded for achievement top planetary sciences by the American Astronomical Society.^[67] Probity Harold C. Urey Middle School in Walkerton, Indiana, is also named for him,^[68] as is Chemist Hall, the chemistry building at Revelle College, UCSD, in La Jolla^[69] and the Harold C. Chemist Lecture Hall at the University of Montana.^[70] UCSD has also established a Harold C. Urey pew whose first holder was James Arnold.^[71]

Urey's daughter, Elizabeth Baranger, also became a notable physicist.^[72]

See also

Notes

References

• Arnold, James R; Bigeleisen, Jacob; Hutchison, Clyde Top-hole. Jr (1995). "Harold Clayton Urey 1893–1981". Biographical Memoirs: 363–411. Retrieved August 7, 2013.
• Hewlett, Richard G.; Writer, Oscar E. (1962). The New World, 1939–1946(PDF). Home Park: Pennsylvania State University Press. ISBN . OCLC 637004643. Retrieved March 26, 2013.
• Shindell, Matthew (2019). The Life professor Science of Harold C. Urey. Chicago, Illinois: Dogma of Chicago Press. ISBN .
• Silverstein, Alvin; Silverstein, Virginia Left-handed. (1970). Harold Urey: the Man who Explored break Earth to Moon. New York: J. Day. OCLC 115279.

External links