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Jesse DuMond
Jesse William Monroe DuMond (July 11, 1892 – December 4, 1976) was an American experimental physicist. He worked at the National Bureau of Standards and later at Caltech where he was involved in experimental approaches to establish accurate measurements of a number of physical constants including the mass and charge of the electron; and Planck's constant. Biography DuMond was born in France as a US citizen, as both of his parents were American. His father was landscape painter Frederick Melville DuMond (1867 - 1927), and his paternal uncle was painter Frank DuMond (1865 – 1951). His mother Louise Adele Kerr died when he was aged two, and young DuMond was taken care of by his maternal grandmother in Paris until the age of seven. He then came to the US to live with his paternal grandparents in Rochester who were in the sheet-metal business. DuMond studied at Monrovia High School where his grandparents moved, and then went to the Throop College of Technology (later to become Calte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron Charge
The elementary charge, usually denoted by is the electric charge carried by a single proton or, equivalently, the magnitude of the negative electric charge carried by a single electron, which has charge −1 . This elementary charge is a fundamental physical constant. In the SI system of units, the value of the elementary charge is exactly defined as e = coulombs, or 160.2176634 zeptocoulombs (zC). Since the 2019 redefinition of SI base units, the seven SI base units are defined by seven fundamental physical constants, of which the elementary charge is one. In the centimetre–gram–second system of units (CGS), the corresponding quantity is . Robert A. Millikan and Harvey Fletcher's oil drop experiment first directly measured the magnitude of the elementary charge in 1909, differing from the modern accepted value by just 0.6%. Under assumptions of the then-disputed atomic theory, the elementary charge had also been indirectly inferred to ~3% accuracy from black ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1976 Deaths
Events January * January 3 – The International Covenant on Economic, Social and Cultural Rights enters into force. * January 5 – The Pol Pot regime proclaims a new constitution for Democratic Kampuchea. * January 11 – The 1976 Philadelphia Flyers–Red Army game results in a 4–1 victory for the National Hockey League's Philadelphia Flyers over HC CSKA Moscow of the Soviet Union. * January 16 – The trial against jailed members of the Red Army Faction (the West German extreme-left militant Baader–Meinhof Group) begins in Stuttgart. * January 18 ** Full diplomatic relations are established between Bangladesh and Pakistan 5 years after the Bangladesh Liberation War. ** The Scottish Labour Party is formed as a breakaway from the UK-wide party. ** Super Bowl X in American football: The Pittsburgh Steelers defeat the Dallas Cowboys, 21–17, in Miami. * January 21 – First commercial Concorde flight, from London to Bahrain. * January 27 ** The United States v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1892 Births
Year 189 ( CLXXXIX) was a common year starting on Wednesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Silanus and Silanus (or, less frequently, year 942 ''Ab urbe condita''). The denomination 189 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Roman Empire * Plague (possibly smallpox) kills as many as 2,000 people per day in Rome. Farmers are unable to harvest their crops, and food shortages bring riots in the city. China * Liu Bian succeeds Emperor Ling, as Chinese emperor of the Han Dynasty. * Dong Zhuo has Liu Bian deposed, and installs Emperor Xian as emperor. * Two thousand eunuchs in the palace are slaughtered in a violent purge in Luoyang, the capital of Han. By topic Arts and sciences * Galen publishes his ''"Treatise on the various temperaments"'' (aka ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Physicists
American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, people who self-identify their ancestry as "American" ** American English, the set of varieties of the English language native to the United States ** Native Americans in the United States, indigenous peoples of the United States * American, something of, from, or related to the Americas, also known as "America" ** Indigenous peoples of the Americas * American (word), for analysis and history of the meanings in various contexts Organizations * American Airlines, U.S.-based airline headquartered in Fort Worth, Texas * American Athletic Conference, an American college athletic conference * American Recordings (record label), a record label previously known as Def American * American University, in Washington, D.C. Sports teams Soccer * B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Wilson (physicist)
Richard Wilson (29 April 1926 – 19 May 2018) was a British-American physicist. His original fields were nuclear and elementary particle physics but branched out into applications of physics in other disciplines. Most of his career he has been a physics professor at Harvard University. Biography Wilson was born in Putney, London, on 29 April 1926 to Dorothy Jennett Kingston, a teacher of French, and Percy Wilson a civil servant in the Board of Education, who had been a Naval officer in World War I. He went to Colet Court school in Hammersmith, a preparatory School for St Paul's School, and then to St Paul's School from 1939 to 1943. He earned a BA in 1946 at Christ Church Oxford, and an MA and D Phil in 1949. He was awarded a Research Lectureship at Christ Church from 1949 to 1954. On leave from this lectureship he visited America on a Guggenheim fellowship in 1950 – 1952, firstly at Rochester New York, then at Stanford University, California. While at Stanford he married ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wolfgang Panofsky
Wolfgang Kurt Hermann "Pief" Panofsky (April 24, 1919 – September 24, 2007), was a German-American physicist who won many awards including the National Medal of Science. Early life Panofsky was born in Berlin, Germany to a family of art historians Dorothea and Erwin Panofsky. His ancestors were of Jewish descent. He spent much of his early life in Hamburg, where his father was a professor of Art History. From the age of 10, he attended the Johanneum, where he received a classical education involving Latin and Ancient Greek, but little science. At the age of 15, he moved with his family to the United States and entered Princeton University. He graduated with an A.B. in physics from Princeton University, as salutatorian of his class, in 1938 after completing a senior thesis, titled "The construction of a high pressure ionisation chamber", under the supervision of Walker Bleakney. He then received his Ph.D. in physics from the California Institute of Technology in 1942 after c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-ray Diffraction
X-ray crystallography is the experimental science determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract into many specific directions. By measuring the angles and intensities of these diffracted beams, a crystallographer can produce a three-dimensional picture of the density of electrons within the crystal. From this electron density, the mean positions of the atoms in the crystal can be determined, as well as their chemical bonds, their crystallographic disorder, and various other information. Since many materials can form crystals—such as salts, metals, minerals, semiconductors, as well as various inorganic, organic, and biological molecules—X-ray crystallography has been fundamental in the development of many scientific fields. In its first decades of use, this method determined the size of atoms, the lengths and types of chemical bonds, and the atomic-scale differences among various mat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oil Drop Experiment
The oil drop experiment was performed by Robert A. Millikan and Harvey Fletcher in 1909 to measure the elementary electric charge (the charge of the electron). The experiment took place in the Ryerson Physical Laboratory at the University of Chicago. Millikan received the Nobel Prize in Physics in 1923. The experiment entailed observing tiny electrically charged droplets of oil located between two parallel metal surfaces, forming the plates of a capacitor. The plates were oriented horizontally, with one plate above the other. A mist of atomized oil drops was introduced through a small hole in the top plate and was ionized by an x-ray, making them negatively charged. First, with zero applied electric field, the velocity of a falling droplet was measured. At terminal velocity, the drag force equals the gravitational force. As both forces depend on the radius in different ways, the radius of the droplet, and therefore the mass and gravitational force, could be determined (using t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compton Effect
Compton scattering, discovered by Arthur Holly Compton, is the scattering of a high frequency photon after an interaction with a charged particle, usually an electron. If it results in a decrease in energy (increase in wavelength) of the photon (which may be an X-ray or gamma ray photon), it is 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. Introduction Compton scattering is an example of elastic scattering of light by a free charged particle, where the wavelength of the scattered light is different from that of the incident radiation. In Compton's original experiment (see Fig. 1), the energy of the X ray photon (≈17 keV) was significantly larger than the binding energy of the atomic electron, so the electrons could be treated as being free after scattering. The amount by which the light's wavelength changes is called th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frank DuMond
Frank Vincent DuMond (August 20, 1865 – February 6, 1951) was one of the most influential teacher-painters in 20th-century America. He was an illustrator and American Impressionist painter of portraits and landscapes, and a prominent teacher who instructed thousands of art students throughout a career spanning over fifty years. Early life and education Frank Vincent DuMond was born on August 20, 1865 in Rochester, New York, to Elisabeth and Alonzo DuMond, partner/owner of an ornamental iron works manufacturer. They also had a younger son, Frederick Melville DuMond (1867 - 1927). Frank DuMond was interested in drawing from a young age, and was involved in the local art scene in the early 1880s. He got a job creating illustrations for a sign painting business.''Archives of American Art Journal'', p. 26. After graduating from a Rochester public school, DuMond moved to New York City in 1884. From 1884 to 1888, he attended the Art Students League of New York, studying under ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Academy Of Sciences
The National Academy of Sciences (NAS) is a United States nonprofit, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the National Academy of Medicine (NAM). As a national academy, new members of the organization are elected annually by current members, based on their distinguished and continuing achievements in original research. Election to the National Academy is one of the highest honors in the scientific field. Members of the National Academy of Sciences serve '' pro bono'' as "advisers to the nation" on science, engineering, and medicine. The group holds a congressional charter under Title 36 of the United States Code. Founded in 1863 as a result of an Act of Congress that was approved by Abraham Lincoln, the NAS is charged with "providing independent, objective advice to the nation on matters related to science and technology. ... to provide scien ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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