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Herbert Callen
Herbert Bernard Callen (July 1, 1919 – May 22, 1993) was an American physicist specializing in thermodynamics and statistical mechanics. He is considered one of the founders of the modern theory of irreversible thermodynamics, and is the author of the classic textbook '' Thermodynamics and an Introduction to Thermostatistics'', published in two editions. During World War II, his services were invoked in the theoretical division of the Manhattan Project. Life and work A native of Philadelphia, Herbert Callen received his Bachelor of Science degree from Temple University. His graduate studies were interrupted by the Manhattan Project. He also worked on a U.S. Navy project concerning guided missiles (Project Bumblebee) at Princeton University in 1945. Callen subsequently completed his PhD in physics at the Massachusetts Institute of Technology (MIT) in 1947. He was supervised by the physicist László Tisza. His doctoral dissertation concerns the Kelvin thermoelectric and thermoma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermodynamics
Thermodynamics is a branch of physics that deals with heat, work, and temperature, and their relation to energy, entropy, and the physical properties of matter and radiation. The behavior of these quantities is governed by the four laws of thermodynamics which convey a quantitative description using measurable macroscopic physical quantities, but may be explained in terms of microscopic constituents by statistical mechanics. Thermodynamics applies to a wide variety of topics in science and engineering, especially physical chemistry, biochemistry, chemical engineering and mechanical engineering, but also in other complex fields such as meteorology. Historically, thermodynamics developed out of a desire to increase the efficiency of early steam engines, particularly through the work of French physicist Sadi Carnot (1824) who believed that engine efficiency was the key that could help France win the Napoleonic Wars. Scots-Irish physicist Lord Kelvin was the first to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johnson–Nyquist Noise
Johnson–Nyquist noise (thermal noise, Johnson noise, or Nyquist noise) is the electronic noise generated by the thermal agitation of the charge carriers (usually the electrons) inside an electrical conductor at equilibrium, which happens regardless of any applied voltage. Thermal noise is present in all electrical circuits, and in sensitive electronic equipment (such as radio receivers) can drown out weak signals, and can be the limiting factor on sensitivity of electrical measuring instruments. Thermal noise increases with temperature. Some sensitive electronic equipment such as radio telescope receivers are cooled to cryogenic temperatures to reduce thermal noise in their circuits. The generic, statistical physical derivation of this noise is called the fluctuation-dissipation theorem, where generalized impedance or generalized susceptibility is used to characterize the medium. Thermal noise in an ideal resistor is approximately white, meaning that the power spectral ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1993 Deaths
File:1993 Events Collage.png, From left, clockwise: The Oslo I Accord is signed in an attempt to resolve the Israeli–Palestinian conflict; The White House (Moscow), Russian White House is shelled during the 1993 Russian constitutional crisis; Czechoslovakia is peacefully Dissolution of Czechoslovakia, dissolved into the Czech Republic and Slovakia; In the United States, the ATF Waco siege, besieges a compound belonging to David Koresh and the Branch Davidians in a search for illegal weapons, which ends in the building being set alight and killing most inside; Eritrea gains independence; A major 1993 Storm of the Century, snow storm passes over the United States and Canada, leading to over 300 fatalities; Drug lord and narcoterrorism, narcoterrorist Pablo Escobar is killed by Military Forces of Colombia, Colombian special forces; Ramzi Yousef and other Islamic terrorism, Islamic terrorists 1993 World Trade Center bombing, detonate a truck bomb in the subterranean garage of List of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1919 Births
Events January * January 1 ** The Czechoslovak Legions occupy much of the self-proclaimed "free city" of Pressburg (now Bratislava), enforcing its incorporation into the new republic of Czechoslovakia. ** HMY ''Iolaire'' sinks off the coast of the Hebrides; 201 people, mostly servicemen returning home to Lewis and Harris, are killed. * January 2– 22 – Russian Civil War: The Red Army's Caspian-Caucasian Front begins the Northern Caucasus Operation against the White Army, but fails to make progress. * January 3 – The Faisal–Weizmann Agreement is signed by Emir Faisal (representing the Arab Kingdom of Hejaz) and Zionist leader Chaim Weizmann, for Arab–Jewish cooperation in the development of a Jewish homeland in Palestine, and an Arab nation in a large part of the Middle East. * January 5 – In Germany: ** Spartacist uprising in Berlin: The Marxist Spartacus League, with the newly formed Communist Party of Germany and the Independent Social D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constantin Carathéodory
Constantin Carathéodory ( el, Κωνσταντίνος Καραθεοδωρή, Konstantinos Karatheodori; 13 September 1873 – 2 February 1950) was a Greek mathematician who spent most of his professional career in Germany. He made significant contributions to real and complex analysis, the calculus of variations, and measure theory. He also created an axiomatic formulation of thermodynamics. Carathéodory is considered one of the greatest mathematicians of his era and the most renowned Greek mathematician since antiquity. Origins Constantin Carathéodory was born in 1873 in Berlin to Greek parents and grew up in Brussels. His father Stephanos, a lawyer, served as the Ottoman ambassador to Belgium, St. Petersburg and Berlin. His mother, Despina, née Petrokokkinos, was from the island of Chios. The Carathéodory family, originally from Bosnochori or Vyssa, was well established and respected in Constantinople, and its members held many important governmental positions. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
