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Francis Birch (August 22, 1903 – January 30, 1992) was an American geophysicist. He is considered one of the founders of solid Earth geophysics. He is also known for his part in the atomic bombing of Hiroshima and Nagasaki. During World War II, Birch participated in the Manhattan Project, working on the design and development of the gun-type nuclear weapon known as Little Boy. He oversaw its manufacture, and went to Tinian to supervise its assembly and loading into ''Enola Gay'', the Boeing B-29 Superfortress tasked with dropping the bomb. A graduate of Harvard University, Birch began working on geophysics as a research assistant. He subsequently spent his entire career at Harvard working in the field, becoming an Associate Professor of Geology in 1943, a professor in 1946, and Sturgis Hooper Professor of Geology in 1949, and professor emeritus in 1974. Birch published over 100 papers. He developed what is now known as the Birch-Murnaghan equation of state in 1947. In 1952 he demonstrated that Earth's mantle is chiefly composed of silicate minerals, with an inner and outer core of molten iron. In two 1961 papers on compressional wave velocities, he established what is now called Birch's law. ==Early life== Albert Francis Birch was born in Washington, D.C., on August 22, 1903, the son of George Albert Birch, who was involved in banking and real estate, and Mary Hemmick Birch, a church choir singer and soloist at St. Matthew's Cathedral in Washington, D.C. He had three younger brothers: David, who became a banker; John, who became a diplomat; and Robert, who became a songwriter. He was educated at Washington, D.C., schools, and Western High School, where he joined the High School Cadets in 1916. In 1920 Birch entered Harvard University on a scholarship. While there he served in Harvard's Reserve Officers' Training Corps Field Artillery Battalion. He graduated magna cum laude in 1924, and received his bachelor of science (S.B.) degree in electrical engineering. Birch went to work in the Engineering Department of the New York Telephone Company. He applied for and received an American Field Service Fellowship in 1926, which he used to travel to Strasbourg, and study at the University of Strasbourg's Institut de Physique under the tutelage of Pierre Weiss.〔(【引用サイトリンク】accessdate=February 4, 2014 )〕 There, he wrote or co-wrote four papers, in French, on topics such as the paramagnetic properties of potassium cyanide, and the magnetic moment of Cu++ ions. On returning to the United States in 1928, Birch went back to Harvard to pursue physics. He was awarded his master of arts (A.M.) degree in 1929, and then commenced work on his 1932 doctor of philosophy (Ph.D.) degree under the supervision of Percy Bridgman,〔 who would receive the Nobel Prize for Physics in 1946. For his thesis, Birch measured the vapor-liquid critical point of mercury. He determined this as 1460±20 °C and 1640±50 kg/cm2, results he published in 1932 in the Physical Review. Around this time, there was an increased interest in geophysics at Harvard University, and Reginald Aldworth Daly established a Committee for Experimental Geology and Geophysics that included Bridgman, astronomer Harlow Shapely, geologists Louis Caryl Graton and D. H. McLaughlin and chemist G. P. Baxter. William Zisman, another one of Bridgman's Ph.D. students, was hired as the committee's research associate, but, having little interest in the study of rocks, he resigned in 1932. The position was then offered to Birch, who had little interest or experience in geology either, but with the advent of the Great Depression, jobs were hard to find, and he accepted. On July 15, 1933, Birch married Barbara Channing, a Bryn Mawr College alumna, and a collateral descendant of the theologian William Ellery Channing. They had three children: Anne Campaspe, Francis (Frank) Sylvanus and Mary Narcissa. Frank later became a professor of geophysics at the University of New Hampshire. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Francis Birch (geophysicist)」の詳細全文を読む スポンサード リンク
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