# Arthur Compton

Last updated

Arthur Compton
Arthur Compton in 1927
Born
Arthur Holly Compton

September 10, 1892
Wooster, Ohio, United States
DiedMarch 15, 1962 (aged 69)
Berkeley, California, United States
Nationality American
Alma mater College of Wooster
Princeton University
Known for Compton scattering
Compton wavelength
Spouse(s)Betty Charity McCloskey (d. 1980)
ChildrenArthur Alan
John Joseph
Awards Nobel Prize for Physics (1927)
Matteucci Medal (1930)
Franklin Medal (1940)
Hughes Medal (1940)
Medal for Merit (1946)
Scientific career
Fields Physics
Institutions Washington University in St. Louis
University of Chicago
University of Minnesota
Doctoral students Luis Walter Alvarez
Winston H. Bostick
Robert S. Shankland
Wu Youxun
Signature
Notes

Arthur Holly Compton (September 10, 1892 – March 15, 1962) was an American physicist who won the Nobel Prize in Physics in 1927 for his 1923 discovery of the Compton effect, which demonstrated the particle nature of electromagnetic radiation. It was a sensational discovery at the time: the wave nature of light had been well-demonstrated, but the idea that light had both wave and particle properties was not easily accepted. He is also known for his leadership of the Manhattan Project's Metallurgical Laboratory, and served as Chancellor of Washington University in St. Louis from 1945 to 1953.

The Nobel Prize in Physics is a yearly award given by the Royal Swedish Academy of Sciences for those who have made the most outstanding contributions for humankind in the field of physics. It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895 and awarded since 1901; the others being the Nobel Prize in Chemistry, Nobel Prize in Literature, Nobel Peace Prize, and Nobel Prize in Physiology or Medicine.

Particle physics is a branch of physics that studies the nature of the particles that constitute matter and radiation. Although the word particle can refer to various types of very small objects, particle physics usually investigates the irreducibly smallest detectable particles and the fundamental interactions necessary to explain their behaviour. By our current understanding, these elementary particles are excitations of the quantum fields that also govern their interactions. The currently dominant theory explaining these fundamental particles and fields, along with their dynamics, is called the Standard Model. Thus, modern particle physics generally investigates the Standard Model and its various possible extensions, e.g. to the newest "known" particle, the Higgs boson, or even to the oldest known force field, gravity.

In physics, electromagnetic radiation refers to the waves of the electromagnetic field, propagating (radiating) through space, carrying electromagnetic radiant energy. It includes radio waves, microwaves, infrared, (visible) light, ultraviolet, X-rays, and gamma rays.

## Contents

In 1919, Compton was awarded one of the first two National Research Council Fellowships that allowed students to study abroad. He chose to go to Cambridge University's Cavendish Laboratory in England, where he studied the scattering and absorption of gamma rays. Further research along these lines led to the discovery of the Compton effect. He used X-rays to investigate ferromagnetism, concluding that it was a result of the alignment of electron spins, and studied cosmic rays, discovering that they were made up principally of positively charged particles.

The Cavendish Laboratory is the Department of Physics at the University of Cambridge, and is part of the School of Physical Sciences. The laboratory was opened in 1874 on the New Museums Site as a laboratory for experimental physics. The laboratory moved to its present site in West Cambridge in 1974. As of 2011, 29 Cavendish researchers have won Nobel Prizes. In the Research Excellence Framework the Cavendish Laboratory is ranked as the 7th-equal best physics department in the country.

Scattering is a general physical process where some forms of radiation, such as light, sound, or moving particles, are forced to deviate from a straight trajectory by one or more paths due to localized non-uniformities in the medium through which they pass. In conventional use, this also includes deviation of reflected radiation from the angle predicted by the law of reflection. Reflections that undergo scattering are often called diffuse reflections and unscattered reflections are called specular (mirror-like) reflections.

In physics, absorption of electromagnetic radiation is the way in which the energy of a photon is taken up by matter, typically the electrons of an atom. Thus, the electromagnetic energy is transformed into internal energy of the absorber, for example thermal energy. The reduction in intensity of a light wave propagating through a medium by absorption of a part of its photons is often called attenuation. Usually, the absorption of waves does not depend on their intensity, although in certain conditions, the medium changes its transparency dependently on the intensity of waves going through, and saturable absorption occurs.

During World War II, Compton was a key figure in the Manhattan Project that developed the first nuclear weapons. His reports were important in launching the project. In 1942, he became head of the Metallurgical Laboratory, with responsibility for producing nuclear reactors to convert uranium into plutonium, finding ways to separate the plutonium from the uranium and to design an atomic bomb. Compton oversaw Enrico Fermi's creation of Chicago Pile-1, the first nuclear reactor, which went critical on December 2, 1942. The Metallurgical Laboratory was also responsible for the design and operation of the X-10 Graphite Reactor at Oak Ridge, Tennessee. Plutonium began being produced in the Hanford Site reactors in 1945.

World War II, also known as the Second World War, was a global war that lasted from 1939 to 1945. The vast majority of the world's countries—including all the great powers—eventually formed two opposing military alliances: the Allies and the Axis. A state of total war emerged, directly involving more than 100 million people from over 30 countries. The major participants threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. World War II was the deadliest conflict in human history, marked by 50 to 85 million fatalities, most of whom were civilians in the Soviet Union and China. It included massacres, the genocide of the Holocaust, strategic bombing, premeditated death from starvation and disease, and the only use of nuclear weapons in war.

A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or from a combination of fission and fusion reactions. Both bomb types release large quantities of energy from relatively small amounts of matter. The first test of a fission ("atomic") bomb released an amount of energy approximately equal to 20,000 tons of TNT (84 TJ). The first thermonuclear ("hydrogen") bomb test released energy approximately equal to 10 million tons of TNT (42 PJ). A thermonuclear weapon weighing little more than 2,400 pounds (1,100 kg) can release energy equal to more than 1.2 million tons of TNT (5.0 PJ). A nuclear device no larger than traditional bombs can devastate an entire city by blast, fire, and radiation. Since they are weapons of mass destruction, the proliferation of nuclear weapons is a focus of international relations policy.

A nuclear reactor, formerly known as an atomic pile, is a device used to initiate and control a self-sustained nuclear chain reaction. Nuclear reactors are used at nuclear power plants for electricity generation and in propulsion of ships. Heat from nuclear fission is passed to a working fluid, which in turn runs through steam turbines. These either drive a ship's propellers or turn electrical generators' shafts. Nuclear generated steam in principle can be used for industrial process heat or for district heating. Some reactors are used to produce isotopes for medical and industrial use, or for production of weapons-grade plutonium. Some are run only for research. As of early 2019, the IAEA reports there are 454 nuclear power reactors and 226 nuclear research reactors in operation around the world.

After the war, Compton became Chancellor of Washington University in St. Louis. During his tenure, the university formally desegregated its undergraduate divisions, named its first female full professor, and enrolled a record number of students after wartime veterans returned to the United States.

## Early life

Arthur Compton was born on September 10, 1892, in Wooster, Ohio, the son of Elias and Otelia Catherine (née Augspurger) Compton, [1] who was named American Mother of the Year in 1939. [2] They were an academic family. Elias was dean of the University of Wooster (later The College of Wooster), which Arthur also attended. Arthur's eldest brother, Karl, who also attended Wooster, earned a PhD in physics from Princeton University in 1912, and was president of MIT from 1930 to 1948. His second brother Wilson likewise attended Wooster, earned his PhD in economics from Princeton in 1916 and was president of the State College of Washington, later Washington State University from 1944 to 1951. [3] All three brothers were members of the Alpha Tau Omega fraternity. [4]

Wooster is a city in the U.S. state of Ohio and the county seat of Wayne County. The municipality is located in northeastern Ohio approximately 50 mi (80 km) SSW of Cleveland, 35 mi (56 km) SW of Akron and 30 mi (48 km) W of Canton. The population was 24,811 at the 2000 census and 26,119 at the 2010 Census. The city is the largest in Wayne County, and the center of the Wooster Micropolitan Statistical Area. Wooster has the main branch and administrative offices of the Wayne County Public Library.

Princeton University is a private Ivy League research university in Princeton, New Jersey. Founded in 1746 in Elizabeth as the College of New Jersey, Princeton is the fourth-oldest institution of higher education in the United States and one of the nine colonial colleges chartered before the American Revolution. The institution moved to Newark in 1747, then to the current site nine years later, and renamed itself Princeton University in 1896.

Wilson Martindale Compton was a long-time trade association executive for the timber industry and also the fifth president of the State College of Washington, now Washington State University.

Compton was initially interested in astronomy, and took a photograph of Halley's Comet in 1910. [5] Around 1913, he described an experiment where an examination of the motion of water in a circular tube demonstrated the rotation of the earth. [6] That year, he graduated from Wooster with a Bachelor of Science degree and entered Princeton, where he received his Master of Arts degree in 1914. [7] Compton then studied for his PhD in physics under the supervision of Hereward L. Cooke, writing his dissertation on "The intensity of X-ray reflection, and the distribution of the electrons in atoms". [8]

Halley's Comet or Comet Halley, officially designated 1P/Halley, is a short-period comet visible from Earth every 75–76 years. Halley is the only known short-period comet that is regularly visible to the naked eye from Earth, and the only naked-eye comet that might appear twice in a human lifetime. Halley last appeared in the inner parts of the Solar System in 1986 and will next appear in mid-2061.

A Bachelor of Science is an undergraduate academic degree awarded for completed courses that generally last three to five years, or a person holding such a degree.

A Master of Arts is a person who was admitted to a type of master's degree awarded by universities in many countries, and the degree is also named Master of Arts in colloquial speech. The degree is usually contrasted with the Master of Science. Those admitted to the degree typically study linguistics, history, communication studies, diplomacy, public administration, political science, or other subjects within the scope of the humanities and social sciences; however, different universities have different conventions and may also offer the degree for fields typically considered within the natural sciences and mathematics. The degree can be conferred in respect of completing courses and passing examinations, research, or a combination of the two.

When Arthur Compton earned his PhD in 1916, he, Karl and Wilson became the first group of three brothers to earn PhDs from Princeton. Later, they would become the first such trio to simultaneously head American colleges. [3] Their sister Mary married a missionary, C. Herbert Rice, who became the principal of Forman Christian College in Lahore. [9] In June 1916, Compton married Betty Charity McCloskey, a Wooster classmate and fellow graduate. [9] They had two sons, Arthur Alan and John Joseph Compton. [10]

Forman Christian College is a independent research liberal arts university located in Lahore, Punjab, Pakistan founded in 1864. The university is administered by the Presbyterian Church and follows an American-style curriculum.

Lahore is a city in the Pakistani province of Punjab. Lahore is the country's second-most populous city after Karachi, and is one of Pakistan's wealthiest cities with an estimated GDP of 58.14 billion (PPP) as of 2015. Lahore is the largest city, and historic cultural centre of the Punjab region, and one of Pakistan's most socially liberal, progressive, and cosmopolitan cities. Compton spent a year as a physics instructor at the University of Minnesota in 1916–17, [11] then two years as a research engineer with the Westinghouse Lamp Company in Pittsburgh, where he worked on the development of the sodium-vapor lamp. During World War I he developed aircraft instrumentation for the Signal Corps. [9] In 1919, Compton was awarded one of the first two National Research Council Fellowships that allowed students to study abroad. He chose to go to Cambridge University's Cavendish Laboratory in England. Working with George Paget Thomson, the son of J. J. Thomson, Compton studied the scattering and absorption of gamma rays. He observed that the scattered rays were more easily absorbed than the original source. [11] [12] Compton was greatly impressed by the Cavendish scientists, especially Ernest Rutherford, Charles Galton Darwin and Arthur Eddington, and he ultimately named his second son after J. J. Thomson. [12] For a time Compton was a deacon at a Baptist church. "Science can have no quarrel", he said, "with a religion which postulates a God to whom men are as His children." [13] ## Career ### Compton effect Returning to the United States, Compton was appointed Wayman Crow Professor of Physics, and Head of the Department of Physics at Washington University in St. Louis in 1920. [7] In 1922, he found that X-ray quanta scattered by free electrons had longer wavelengths and, in accordance with Planck's relation, less energy than the incoming X-rays, the surplus energy having been transferred to the electrons. This discovery, known as the "Compton effect" or "Compton scattering", demonstrated the particle concept of electromagnetic radiation. [14] [15] In 1923, Compton published a paper in the Physical Review that explained the X-ray shift by attributing particle-like momentum to photons, something Einstein had invoked for his 1905 Nobel Prize–winning explanation of the photo-electric effect. First postulated by Max Planck in 1900, these were conceptualized as elements of light "quantized" by containing a specific amount of energy depending only on the frequency of the light. [16] In his paper, Compton derived the mathematical relationship between the shift in wavelength and the scattering angle of the X-rays by assuming that each scattered X-ray photon interacted with only one electron. His paper concludes by reporting on experiments that verified his derived relation: ${\displaystyle \lambda '-\lambda ={\frac {h}{m_{e}c}}(1-\cos {\theta }),}$ where ${\displaystyle \lambda }$ is the initial wavelength, ${\displaystyle \lambda '}$ is the wavelength after scattering, ${\displaystyle h}$ is the Planck constant, ${\displaystyle m_{e}}$ is the electron rest mass, ${\displaystyle c}$ is the speed of light, and ${\displaystyle \theta }$ is the scattering angle. [15] The quantity hmec is known as the Compton wavelength of the electron; it is equal to 2.43×10−12 m. The wavelength shift λ′λ lies between zero (for θ = 0°) and twice the Compton wavelength of the electron (for θ = 180°). [17] He found that some X-rays experienced no wavelength shift despite being scattered through large angles; in each of these cases the photon failed to eject an electron. Thus the magnitude of the shift is related not to the Compton wavelength of the electron, but to the Compton wavelength of the entire atom, which can be upwards of 10,000 times smaller. [15] "When I presented my results at a meeting of the American Physical Society in 1923," Compton later recalled, "it initiated the most hotly contested scientific controversy that I have ever known." [18] The wave nature of light had been well demonstrated, and the idea that it could have a dual nature was not easily accepted. It was particularly telling that diffraction in a crystal lattice could only be explained with reference to its wave nature. It earned Compton the Nobel Prize in Physics in 1927. Compton and Alfred W. Simon developed the method for observing at the same instant individual scattered X-ray photons and the recoil electrons. In Germany, Walther Bothe and Hans Geiger independently developed a similar method. [14] ### X-rays In 1923, Compton moved to the University of Chicago as Professor of Physics, [7] a position he would occupy for the next 22 years. [14] In 1925, he demonstrated that the scattering of 130,000-volt X-rays from the first sixteen elements in the periodic table (hydrogen through sulfur) were polarized, a result predicted by J. J. Thomson. William Duane from Harvard University spearheaded an effort to prove that Compton's interpretation of the Compton effect was wrong. Duane carried out a series of experiments to disprove Compton, but instead found evidence that Compton was correct. In 1924, Duane conceded that this was the case. [14] Compton investigated the effect of X-rays on the sodium and chlorine nuclei in salt. He used X-rays to investigate ferromagnetism, concluding that it was a result of the alignment of electron spins. [19] In 1926, he became a consultant for the Lamp Department at General Electric. In 1934, he returned to England as Eastman visiting professor at Oxford University. While there General Electric asked him to report on activities at General Electric Company plc's research laboratory at Wembley. Compton was intrigued by the possibilities of the research there into fluorescent lamps. His report prompted a research program in America that developed it. [20] [21] Compton's first book, X-Rays and Electrons, was published in 1926. In it he showed how to calculate the densities of diffracting materials from their X-ray diffraction patterns. [19] He revised his book with the help of Samuel K. Allison to produce X-Rays in Theory and Experiment (1935). This work remained a standard reference for the next three decades. [22] ### Cosmic rays By the early 1930s, Compton had become interested in cosmic rays. At the time, their existence was known but their origin and nature remained speculative. Their presence could be detected using a spherical "bomb" containing compressed air or argon gas and measuring its electrical conductivity. Trips to Europe, India, Mexico, Peru and Australia gave Compton the opportunity to measure cosmic rays at different altitudes and latitudes. Along with other groups who made observations around the globe, they found that cosmic rays were 15 per cent more intense at the poles than at the equator. Compton attributed this to the effect of cosmic rays being made up principally of charged particles, rather than photons as Robert Millikan had suggested, with the latitude effect being due to Earth's magnetic field. [23] ## Manhattan Project In April 1941, Vannevar Bush, head of the wartime National Defense Research Committee (NDRC), created a special committee headed by Compton to report on the NDRC uranium program. Compton's report, which was submitted in May 1941, foresaw the prospects of developing radiological weapons, nuclear propulsion for ships, and nuclear weapons using uranium-235 or the recently discovered plutonium. [24] In October he wrote another report on the practicality of an atomic bomb. For this report, he worked with Enrico Fermi on calculations of the critical mass of uranium-235, conservatively estimating it to be between 20 kilograms (44 lb) and 2 tonnes (2.0 long tons; 2.2 short tons). He also discussed the prospects for uranium enrichment with Harold Urey, spoke with Eugene Wigner about how plutonium might be produced in a nuclear reactor, and with Robert Serber about how the plutonium produced in a reactor might be separated from uranium. His report, submitted in November, stated that a bomb was feasible, although he was more conservative about its destructive power than Mark Oliphant and his British colleagues. [25] The final draft of Compton's November report made no mention of using plutonium, but after discussing the latest research with Ernest Lawrence, Compton became convinced that a plutonium bomb was also feasible. In December, Compton was placed in charge of the plutonium project. [26] He hoped to achieve a controlled chain reaction by January 1943, and to have a bomb by January 1945. To tackle the problem, he had the different research groups working on plutonium and nuclear reactor design at Columbia University, Princeton University and the University of California, Berkeley, concentrated together as the Metallurgical Laboratory in Chicago. Its objectives were to produce reactors to convert uranium to plutonium, to find ways to chemically separate the plutonium from the uranium, and to design and build an atomic bomb. [27] In June 1942, the United States Army Corps of Engineers assumed control of the nuclear weapons program and Compton's Metallurgical Laboratory became part of the Manhattan Project. [28] That month, Compton gave Robert Oppenheimer responsibility for bomb design. [29] It fell to Compton to decide which of the different types of reactor designs that the Metallurgical Laboratory scientists had devised should be pursued, even though a successful reactor had not yet been built. [30] When labor disputes delayed construction of the Metallurgical Laboratory's new home in the Red Gate Woods, Compton decided to build Chicago Pile-1, the first nuclear reactor, under the stands at Stagg Field. [31] Under Fermi's direction, it went critical on December 2, 1942. [32] Compton arranged for Mallinckrodt to undertake the purification of uranium ore, [33] and with DuPont to build the plutonium semi-works at Oak Ridge, Tennessee. [34] A major crisis for the plutonium program occurred in July 1943, when Emilio Segrè's group confirmed that plutonium created in the X-10 Graphite Reactor at Oak Ridge contained high levels of plutonium-240. Its spontaneous fission ruled out the use of plutonium in a gun-type nuclear weapon. Oppenheimer's Los Alamos Laboratory met the challenge by designing and building an implosion-type nuclear weapon. [25] Compton was at the Hanford site in September 1944 to watch the first reactor being brought online. The first batch of uranium slugs was fed into Reactor B at Hanford in November 1944, and shipments of plutonium to Los Alamos began in February 1945. [35] Throughout the war, Compton would remain a prominent scientific adviser and administrator. In 1945, he served, along with Lawrence, Oppenheimer, and Fermi, on the Scientific Panel that recommended military use of the atomic bomb against Japan. [36] He was awarded the Medal for Merit for his services to the Manhattan Project. [37] ## Return to Washington University After the war ended, Compton resigned his chair as Charles H. Swift Distinguished Service Professor of Physics at the University of Chicago and returned to Washington University in St. Louis, where he was inaugurated as the university's ninth Chancellor in 1946. [37] During Compton's time as Chancellor, the university formally desegregated its undergraduate divisions in 1952, named its first female full professor, and enrolled record numbers of students as wartime veterans returned to the United States. His reputation and connections in national scientific circles allowed him to recruit many nationally renowned scientific researchers to the university. Despite Compton's accomplishments, he was criticized then, and subsequently by historians, for moving too slowly toward full racial integration, making Washington University the last major institution of higher learning in St. Louis to open its doors to African Americans. [38] Compton retired as Chancellor in 1954, but remained on the faculty as Distinguished Service Professor of Natural Philosophy until his retirement from the full-time faculty in 1961. In retirement he wrote Atomic Quest, a personal account of his role in the Manhattan Project, which was published in 1956. [37] ## Philosophy Compton was one of a handful of scientists and philosophers to propose a two-stage model of free will. Others include William James, Henri Poincaré, Karl Popper, Henry Margenau, and Daniel Dennett. [39] In 1931, Compton championed the idea of human freedom based on quantum indeterminacy, and invented the notion of amplification of microscopic quantum events to bring chance into the macroscopic world. In his somewhat bizarre mechanism, he imagined sticks of dynamite attached to his amplifier, anticipating the Schrödinger's cat paradox, which was published in 1935. [40] Reacting to criticisms that his ideas made chance the direct cause of people's actions, Compton clarified the two-stage nature of his idea in an Atlantic Monthly article in 1955. First there is a range of random possible events, then one adds a determining factor in the act of choice. [41] A set of known physical conditions is not adequate to specify precisely what a forthcoming event will be. These conditions, insofar as they can be known, define instead a range of possible events from among which some particular event will occur. When one exercises freedom, by his act of choice he is himself adding a factor not supplied by the physical conditions and is thus himself determining what will occur. That he does so is known only to the person himself. From the outside one can see in his act only the working of physical law. It is the inner knowledge that he is in fact doing what he intends to do that tells the actor himself that he is free. [41] ## Death and legacy Compton died in Berkeley, California, from a cerebral hemorrhage on March 15, 1962. He was survived by his wife, who died in 1980 and sons. Compton is buried in the Wooster Cemetery in Wooster, Ohio. [10] Before his death, he was Professor-at-Large at the University of California, Berkeley for Spring 1962. [42] Compton received many awards in his lifetime, including the Nobel Prize for Physics in 1927, the Matteucci Gold Medal in 1933, the Royal Society's Hughes Medal and the Franklin Institute's Benjamin Franklin Medal in 1940. [43] He is commemorated in various ways. The Compton crater on the Moon is co-named for Compton and his brother Karl. [44] The physics research building at Washington University in St Louis is named in his honor, [45] as is the university's top fellowship for undergraduate students studying math, physics, or planetary science. [46] Compton invented a more gentle, elongated, and ramped version of the speed bump called the "Holly hump," many of which are on the roads of the Washington University campus. [47] The University of Chicago Residence Halls remembered Compton and his achievements by dedicating Arthur H. Compton House in Chicago in his honor. [48] It is now listed as a National Historic Landmark. [49] Compton also has a star on the St. Louis Walk of Fame. [50] NASA's Compton Gamma Ray Observatory was named in honor of Compton. The Compton effect is central to the gamma ray detection instruments aboard the observatory. [51] ## Bibliography • Compton, Arthur (1926). X-Rays and Electrons: An Outline of Recent X-Ray Theory. New York: D. Van Nostrand Company, Inc. OCLC 1871779. • Compton, Arthur; with Allison, S. K. (1935). X-Rays in Theory and Experiment. New York: D. Van Nostrand Company, Inc. OCLC 853654. • Compton, Arthur (1935). The Freedom of Man. New Haven: Yale University Press. OCLC 5723621. • Compton, Arthur (1940). The Human Meaning of Science. Chapel Hill: University of North Carolina Press. OCLC 311688. • Compton, Arthur (1949). Man's Destiny in Eternity. Boston: Beacon Press. OCLC 4739240. • Compton, Arthur (1956). Atomic Quest. New York: Oxford University Press. OCLC 173307. • Compton, Arthur (1967). Johnston, Marjorie, ed. The Cosmos of Arthur Holly Compton. New York: Alfred A. Knopf. OCLC 953130. • Compton, Arthur (1973). Shankland, Robert S., ed. Scientific Papers of Arthur Holly Compton. Chicago: University of Chicago Press. ISBN 978-0-226-11430-9. OCLC 962635. ## Notes 1. Hockey 2007, p. 244. 2. "Past National Mothers of the Year". American Mothers, Inc. Archived from the original on March 23, 2011. Retrieved July 23, 2013. 3. Compton 1967, p. 425. 4. "The Official History of the Beta Beta Chapter of the Alpha Tau Omega Fraternity". Alpha Tau Fraternity. Retrieved August 10, 2013. 5. Compton 1967, pp. 11–12. 6. Compton, A. H. (May 23, 1913). "A Laboratory Method of Demonstrating the Earth's Rotation". Science. 37 (960): 803–06. Bibcode:1913Sci....37..803C. doi:10.1126/science.37.960.803. PMID 17838837. 7. "Arthur H. Compton – Biography". Nobel Foundation. Retrieved March 19, 2013. 8. "Arthur Holly Compton (1892–1962)" (PDF). University of Notre Dame . Retrieved July 24, 2013. 9. Allison 1965, p. 82. 10. Allison 1965, p. 94. 11. Allison 1965, p. 83. 12. Compton 1967, p. 27. 13. "Science: Cosmic Clearance". Time Magazine . January 13, 1936. 14. Allison 1965, pp. 84–86. 15. Compton, Arthur H. (May 1923). "A Quantum Theory of the Scattering of X-Rays by Light Elements". Physical Review . 21 (5): 483–502. Bibcode:1923PhRv...21..483C. doi:10.1103/PhysRev.21.483 . Retrieved September 26, 2013. 16. Gamow 1966, pp. 17–23. 17. "The Compton wavelength of the electron". University of California Riverside. Archived from the original on 1996-11-10. Retrieved August 18, 2013. 18. Compton 1967, p. 36. 19. Allison 1965, pp. 87–88. 20. Allison 1965, pp. 88–89. 21. "Eastman Professorship". The Association of American Rhodes Scholars. Retrieved July 26, 2013. 22. Allison 1965, p. 90. 23. Compton 1967, pp. 157–163. 24. Hewlett & Anderson 1962, pp. 36–38. 25. Hewlett & Anderson 1962, pp. 46–49. 26. Hewlett & Anderson 1962, pp. 50–51. 27. Hewlett & Anderson 1962, pp. 54–55. 28. Hewlett & Anderson 1962, pp. 74–75. 29. Hewlett & Anderson 1962, p. 103. 30. Hewlett & Anderson 1962, pp. 180–181. 31. Hewlett & Anderson 1962, pp. 108–109. 32. Hewlett & Anderson 1962, p. 174. 33. Allison 1965, p. 92. 34. Hewlett & Anderson 1962, pp. 190–191. 35. Hewlett & Anderson 1962, pp. 304–310. 36. "Recommendations on the Immediate Use of Nuclear Weapons". nuclearfiles.org. Retrieved July 27, 2013. 37. Allison 1965, p. 93. 38. Pfeiffenberger, Amy M. (Winter 1989). "Democracy at Home: The Struggle to Desegregate Washington University in the Postwar Era". Gateway-Heritage. Missouri Historical Society. 10 (3): 17–24. 39. "Two-Stage Models for Free Will". The Information Philosopher. Retrieved July 27, 2013. 40. Compton, A. H. (August 14, 1931). "The Uncertainty Principle and Free Will". Science. 74 (1911): 172. Bibcode:1931Sci....74..172C. doi:10.1126/science.74.1911.172. PMID 17808216. 41. Compton 1967, p. 121. 42. "Arthur Holly Compton: Systemwide". California Digital Library. Retrieved 24 May 2017. 43. Allison 1965, p. 97. 44. "Compton". Tangient LLC. Retrieved July 27, 2013. 45. "Arthur Holly Compton Laboratory of Physics". Washington University . Retrieved July 27, 2013. 46. "Honorary Scholars Program in Arts and Sciences". Washington University . Retrieved March 25, 2018. 47. "Compton Speed Bumps for Traffic Control, 1953". Washington University. Archived from the original on July 19, 2013. Retrieved July 27, 2013. 48. "Compton House". University of Chicago. Archived from the original on December 1, 2005. Retrieved July 27, 2013. 49. "Compton, Arthur H., House". National Historic Landmark summary listing. National Park Service. Archived from the original on February 12, 2012. Retrieved July 27, 2013. 50. St. Louis Walk of Fame. "St. Louis Walk of Fame Inductees". stlouiswalkoffame.org. Retrieved 25 April 2013. 51. "The CGRO Mission (1991–2000)". NASA . Retrieved July 27, 2013. ## Related Research Articles Enrico Fermi was an Italian and naturalized-American physicist and the creator of the world's first nuclear reactor, the Chicago Pile-1. He has been called the "architect of the nuclear age" and the "architect of the atomic bomb". He was one of very few physicists to excel in both theoretical physics and experimental physics. Fermi held several patents related to the use of nuclear power, and was awarded the 1938 Nobel Prize in Physics for his work on induced radioactivity by neutron bombardment and for the discovery of transuranium elements. 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Compton scattering, discovered by Arthur Holly Compton, is the scattering of a photon by a charged particle, usually an electron. It results in a decrease in energy of the photon, called the Compton effect. Part of the energy of the photon is transferred to the recoiling electron. Inverse Compton scattering occurs when a charged particle transfers part of its energy to a photon.

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Seth Henry Neddermeyer was an American physicist who co-discovered the muon, and later championed the Implosion-type nuclear weapon while working on the Manhattan Project at the Los Alamos Laboratory during World War II.

Chicago Pile-1 (CP-1) was the world's first nuclear reactor. On 2 December 1942, the first human-made self-sustaining nuclear chain reaction was initiated in CP-1, during an experiment led by Enrico Fermi. The secret development of the reactor was the first major technical achievement of the Manhattan Project, the Allied effort to create atomic bombs during World War II. Although the project's civilian and military leaders had misgivings about the possibility of a disastrous runaway reaction, they nevertheless decided due to time pressure to carry out the experiment in a densely populated area. It was built by the Metallurgical Laboratory at the University of Chicago, under the west viewing stands of the original Stagg Field. Fermi described the apparatus as "a crude pile of black bricks and wooden timbers".

The Metallurgical Laboratory was a scientific laboratory at the University of Chicago that was established in February 1942 to study and use the newly discovered chemical element plutonium. It researched plutonium's chemistry and metallurgy, designed the world's first nuclear reactors to produce it, and developed chemical processes to separate it from other elements. In August 1942 the lab's chemical section was the first to chemically separate a weighable sample of plutonium, and on 2 December 1942, the Met Lab produced the first controlled nuclear chain reaction, in the reactor Chicago Pile-1, which was constructed under the stands of the university's old football stadium, Stagg Field.

Samuel King Allison was an American physicist, most notable for his role in the Manhattan Project, for which he was awarded the Medal for Merit. He was director of the Metallurgical Laboratory from 1943 until 1944, and later worked at the Los Alamos Laboratory — where he "rode herd" on the final stages of the project as part of the "Cowpuncher Committee", and read the countdown for the detonation of the Trinity nuclear test. After the war, he returned to the University of Chicago to direct the Institute for Nuclear Studies and was involved in the "scientists' movement", lobbying for civilian control of nuclear weapons.

The Manhattan Project was a research and development project that produced the first atomic bombs during World War II. It was led by the United States with the support of the United Kingdom and Canada. From 1942 to 1946, the project was under the direction of Major General Leslie Groves of the US Army Corps of Engineers. The Army component of the project was designated the Manhattan District; "Manhattan" gradually became the codename for the entire project. Along the way, the project absorbed its earlier British counterpart, Tube Alloys. The Manhattan Project began modestly in 1939, but grew to employ more than 130,000 people and cost nearly US\$2 billion. Over 90% of the cost was for building factories and producing the fissionable materials, with less than 10% for development and production of the weapons.

Electron scattering occurs when electrons are deviated from their original trajectory. This is due to the electrostatic forces within matter interaction or, if an external magnetic field is present, the electron may be deflected by the Lorentz force. This scattering typically happens with solids such as metals, semiconductors and insulators; and is a limiting factor in integrated circuits and transistors.

The X-10 Graphite Reactor at Oak Ridge National Laboratory in Oak Ridge, Tennessee, formerly known as the Clinton Pile and X-10 Pile, was the world's second artificial nuclear reactor, and the first designed and built for continuous operation. It was built during World War II as part of the Manhattan Project.

Joseph William Kennedy was an American chemist who was a co-discoverer of plutonium, along with Glenn T. Seaborg, Edwin McMillan and Arthur Wahl. During World War II he was head of the CM Division at the Manhattan Project's Los Alamos laboratory, where he oversaw research onto the chemistry and metallurgy of uranium and plutonium. After the war, he was recruited as a professor at Washington University in St. Louis, where he is credited with transforming a university primarily concerned with undergraduate teaching into one that also boasts strong graduate and research programs. He died of cancer of the stomach at the age of 40.

Walter Henry Zinn was an American nuclear physicist who was the first director of the Argonne National Laboratory from 1946 to 1956. He worked at the Manhattan Project's Metallurgical Laboratory during World War II, and supervised the construction of Chicago Pile-1, the world's first nuclear reactor, which went critical on December 2, 1942, at the University of Chicago. At Argonne he designed and built several new reactors, including Experimental Breeder Reactor I, the first nuclear reactor to produce electric power, which went live on December 20, 1951.

The Arthur H. Compton House is a historic house at 5637 South Woodlawn Avenue in Chicago, Illinois. Built in 1916, it was the residence of physicist Arthur Compton (1892-1962) from the late 1920s until 1945. Compton discovered the Compton Effect in 1923, proving that light has both a particle and a wave aspect. Compton received the Nobel Prize in Physics in 1927 for this discovery. His house was designated a National Historic Landmark in 1976.

The Montreal Laboratory in Montreal, Quebec, Canada, was established by the National Research Council of Canada during World War II to undertake nuclear research in collaboration with the United Kingdom, and to absorb some of the scientists and work of the Tube Alloys nuclear project in Britain. It became part of the Manhattan Project, and designed and built some of the world's first nuclear reactors.

The bismuth-phosphate process was used to extract plutonium from irradiated uranium taken from nuclear reactors. It was developed during World War II by Stanley G. Thompson, a chemist working for the Manhattan Project at the University of California, Berkeley. This process was used to produce plutonium at the Hanford Site. Plutonium was used in the atomic bomb that was used in the atomic bombing of Nagasaki in August 1945. The process was superseded in the 1950s by the REDOX and PUREX processes.

Martin Dewey Whitaker was an American physicist who was the first director of the Clinton Laboratories during World War II. He served as President of Lehigh University from 1946 until his death in 1960.

Harley A. Wilhelm was an American chemist who helped to establish the United States Department of Energy's Ames Laboratory at Iowa State University. His uranium extraction process helped make it possible for the Manhattan Project to build the first atomic bombs.

Norman Hilberry was an American physicist, best known as the director of the Argonne National Laboratory from 1956 to 1961. In December 1942 he was the man who stood ready with an axe to cut the scram line during the start up of Chicago Pile-1, the world's first nuclear reactor to achieve criticality.

The Ames Project was a research and development project that was part of the larger Manhattan Project to build the first atomic bombs during World War II. It was founded by Frank Spedding from Iowa State College in Ames, Iowa as an offshoot of the Metallurgical Laboratory at the University of Chicago devoted to chemistry and metallurgy, but became a separate project in its own right. The Ames Project developed the Ames Process, a method for preparing pure uranium metal that the Manhattan Project needed for its atomic bombs and nuclear reactors. Between 1942 and 1945, it produced over 1,000 short tons (910 t) of uranium metal. It also developed methods of preparing and casting thorium, cerium and beryllium. In October 1945 Iowa State College received the Army-Navy "E" Award for Excellence in Production, an award usually only given to industrial organizations. In 1947 it became the Ames Laboratory, a national laboratory under the Atomic Energy Commission.