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Nuclear Astrophysics
Nuclear astrophysics is an interdisciplinary part of both nuclear physics and astrophysics, involving close collaboration among researchers in various subfields of each of these fields. This includes, notably, nuclear reactions and their rates as they occur in cosmic environments, and modeling of astrophysical objects where these nuclear reactions may occur, but also considerations of cosmic evolution of isotopic and elemental composition (often called chemical evolution). Constraints from observations involve multiple messengers, all across the electromagnetic spectrum ( nuclear gamma-rays, X-rays, optical, and radio/sub-mm astronomy), as well as isotopic measurements of solar-system materials such as meteorites and their stardust inclusions, cosmic rays, material deposits on Earth and Moon). Nuclear physics experiments address stability (i.e., lifetimes and masses) for atomic nuclei well beyond the regime of stable nuclides into the realm of radioactive/unstable nuclei, almost t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Physics
Nuclear physics is the field of physics that studies atomic nuclei and their constituents and interactions, in addition to the study of other forms of nuclear matter. Nuclear physics should not be confused with atomic physics, which studies the atom as a whole, including its electrons. Discoveries in nuclear physics have led to applications in many fields. This includes nuclear power, nuclear weapons, nuclear medicine and magnetic resonance imaging, industrial and agricultural isotopes, ion implantation in materials engineering, and radiocarbon dating in geology and archaeology. Such applications are studied in the field of nuclear engineering. Particle physics evolved out of nuclear physics and the two fields are typically taught in close association. Nuclear astrophysics, the application of nuclear physics to astrophysics, is crucial in explaining the inner workings of stars and the origin of the chemical elements. History The history of nuclear physics as a discipl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hans Suess
Hans Eduard Suess (December 16, 1909 – September 20, 1993) was an Austrian born United States, American physical chemist and nuclear physicist. He was a grandson of the Austrian geologist Eduard Suess. Career Suess earned his Ph.D. in chemistry from the University of Vienna in 1935 under the supervision of Philipp Gross. During World War II, he was part of a team of Germany, German scientists studying nuclear power and was advisor to the production of heavy water in a Norwegian plant (see Operation Gunnerside). After the war, he collaborated on the Nuclear shell model, shell model of the atomic nucleus with future (1963) Nobel Prize in Physics, Nobel Prize winner J. Hans D. Jensen, Hans Jensen. In 1950, Suess emigrated to the United States. He did research in the field of cosmochemistry, investigating the Abundance of the chemical elements#Abundance of elements in the Solar System, abundance of certain elements in meteorites with Harold Urey (Nobel Prize in Chemistry, 1934) a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physikalische Zeitschrift
''Physikalische Zeitschrift'' (English: ''Physical Journal'') was a German scientific journal of physics published from 1899 to 1945 by S. Hirzel Verlag. In 1924, it merged with ''Jahrbuch der Radioaktivität und Elektronik''. From 1944 onwards, the journal published the ''Reichsberichte für Physik'' (English: ''Reich Reports for Physics''). Several publications of great historical significance have been published in it, such as Albert Einstein's "Über die Entwicklung unserer Anschauungen über das Wesen und die Konstitution der Strahlung" (''On the Development of Our Views Concerning the Nature and Constitution of Radiation'') and Carl von Weizsäcker's work on the source of energy in stars. During its life, it was edited by several prominent physicists, such as Peter Debye. Towards the end of its life, it was considered to represent "the more conservative elements within the German physics community", alongside ''Annalen der Physik''. See also * ''Zeitschrift für Physik'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CNO Cycle
The CNO cycle (for carbon–nitrogen–oxygen; sometimes called Bethe–Weizsäcker cycle after Hans Albrecht Bethe and Carl Friedrich von Weizsäcker) is one of the two known sets of fusion reactions by which stars convert hydrogen to helium, the other being the proton–proton chain reaction (p–p cycle), which is more efficient at the Sun's core temperature. The CNO cycle is hypothesized to be dominant in stars that are more than 1.3 times as massive as the Sun. Unlike the proton-proton reaction, which consumes all its constituents, the CNO cycle is a catalytic cycle. In the CNO cycle, four protons fuse, using carbon, nitrogen, and oxygen isotopes as catalysts, each of which is consumed at one step of the CNO cycle, but re-generated in a later step. The end product is one alpha particle (a stable helium nucleus), two positrons, and two electron neutrinos. There are various alternative paths and catalysts involved in the CNO cycles, all these cycles have the same ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carl Friedrich Von Weizsäcker
Carl Friedrich Freiherr von Weizsäcker (; 28 June 1912 – 28 April 2007) was a German physicist and philosopher. He was the longest-living member of the team which performed nuclear research in Germany during the Second World War, under Werner Heisenberg's leadership. There is ongoing debate as to whether or not he and the other members of the team actively and willingly pursued the development of a nuclear bomb for Germany during this time. A member of the prominent Weizsäcker family, he was son of the diplomat Ernst von Weizsäcker, elder brother of the former German President Richard von Weizsäcker, father of the physicist and environmental researcher Ernst Ulrich von Weizsäcker and father-in-law of the former General Secretary of the World Council of Churches Konrad Raiser. Weizsäcker made important theoretical discoveries regarding energy production in stars from nuclear fusion processes. He also did influential theoretical work on planetary formation in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hans Bethe
Hans Albrecht Bethe (; July 2, 1906 – March 6, 2005) was a German-American theoretical physicist who made major contributions to nuclear physics, astrophysics, quantum electrodynamics, and solid-state physics, and who won the 1967 Nobel Prize in Physics for his work on the theory of stellar nucleosynthesis. For most of his career, Bethe was a professor at Cornell University.Available at www.JamesKeckCollectedWorks.or are the class notes taken by one of his students at Cornell from the graduate courses on Nuclear Physics and on Applications of Quantum Mechanics he taught in the spring of 1947. During World War II, he was head of the Theoretical Division at the secret Los Alamos National Laboratory, Los Alamos laboratory that developed the first atomic bombs. There he played a key role in calculating the critical mass of the weapons and developing the theory behind the implosion method used in both the Trinity test and the "Fat Man" weapon dropped on Nagasaki in August 1945. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Observatory (journal)
''The Observatory'' is a publication, variously described as a journal, a magazine and a review, devoted to astronomy. It appeared regularly starting in 1877, and it is now published every two months. The current editors are David Stickland, Bob Argyle and Steve Fossey. Although it is not published by the Royal Astronomical Society, it publishes the reports of its meetings. Other features are the extensive book reviews and "Here and There", a collection of misprints and ridiculous statements of astronomical interest. The founder and first editor (1877–1882) was William Christie, then chief assistant at the Royal Observatory and later Astronomer Royal. Notable subsequent editors include: * Arthur Eddington (1913–1919) * Harold Spencer Jones (1915–1923) * Richard van der Riet Woolley (1933–1939) * William McCrea (1935–1937) * Margaret Burbidge (1948–1951) * Antony Hewish (1957–1961) * Donald Lynden-Bell (1967–1969) * Carole Jordan (1968–1973) * Jocelyn Bel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthur Stanley Eddington
Sir Arthur Stanley Eddington (28 December 1882 – 22 November 1944) was an English astronomer, physicist, and mathematician. He was also a philosopher of science and a populariser of science. The Eddington limit, the natural limit to the luminosity of stars, or the radiation generated by accretion onto a compact object, is named in his honour. Around 1920, he foreshadowed the discovery and mechanism of nuclear fusion processes in stars, in his paper "The Internal Constitution of the Stars".The Internal Constitution of the Stars A. S. Eddington The Scientific Monthly Vol. 11, No. 4 (Oct., 1920), pp. 297–303 At that time, the source of stellar energy was a complete mystery; Eddington was the first to correctly speculate that the source was fusion of hydrogen into helium. Eddington wrote a number of articles that announced and explained Einstein's theory of general relativity to the English-speaking world. World War I had severed many lines of scientific communication, and ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Francis William Aston
Francis William Aston Fellow of the Royal Society, FRS (1 September 1877 – 20 November 1945) was a British chemist and physicist who won the 1922 Nobel Prize in Chemistry for his discovery, by means of his mass spectrograph, of isotopes in many non-radioactive elements and for his enunciation of the whole number rule. He was a fellow of the Royal Society and Fellow of Trinity College, Cambridge. Biography Early life Francis Aston was born in Harborne, now part of Birmingham, on 1 September 1877. He was the third child and second son of William Aston and Fanny Charlotte Hollis. He was educated at the Harborne Vicarage School and later Malvern College in Worcestershire where he was a boarder. In 1893 Francis William Aston began his university studies at Mason College (which was then external college of University of London) where he was taught physics by John Henry Poynting and chemistry by Percy F. Frankland, Frankland and William A. Tilden, Tilden. From 1896 on he conducted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Chadwick
Sir James Chadwick, (20 October 1891 – 24 July 1974) was an English physicist who was awarded the 1935 Nobel Prize in Physics for his discovery of the neutron in 1932. In 1941, he wrote the final draft of the MAUD Report, which inspired the U.S. government to begin serious atom bomb research efforts. He was the head of the British team that worked on the Manhattan Project during World War II. He was knighted in Britain in 1945 for his achievements in physics. Chadwick graduated from the Victoria University of Manchester in 1911, where he studied under Ernest Rutherford (known as the "father of nuclear physics"). At Manchester, he continued to study under Rutherford until he was awarded his MSc in 1913. The same year, Chadwick was awarded an 1851 Research Fellowship from the Royal Commission for the Exhibition of 1851. He elected to study beta radiation under Hans Geiger in Berlin. Using Geiger's recently developed Geiger counter, Chadwick was able to demonstrate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ernest Rutherford
Ernest Rutherford, 1st Baron Rutherford of Nelson, (30 August 1871 – 19 October 1937) was a New Zealand physicist who came to be known as the father of nuclear physics. ''Encyclopædia Britannica'' considers him to be the greatest experimentalist since Michael Faraday (1791–1867). Apart from his work in his homeland, he spent a substantial amount of his career abroad, in both Canada and the United Kingdom. In early work, Rutherford discovered the concept of radioactive half-life, the radioactive element radon, and differentiated and named alpha and beta radiation. This work was performed at McGill University in Montreal, Quebec, Canada. It is the basis for the Nobel Prize in Chemistry he was awarded in 1908 "for his investigations into the disintegration of the elements, and the chemistry of radioactive substances", for which he was the first Oceanian Nobel laureate, and the first to perform the awarded work in Canada. In 1904, he was elected as a member to the Am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atomic Nucleus
The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in 1911 by Ernest Rutherford based on the 1909 Geiger–Marsden gold foil experiment. After the discovery of the neutron in 1932, models for a nucleus composed of protons and neutrons were quickly developed by Dmitri Ivanenko and Werner Heisenberg. An atom is composed of a positively charged nucleus, with a cloud of negatively charged electrons surrounding it, bound together by electrostatic force. Almost all of the mass of an atom is located in the nucleus, with a very small contribution from the electron cloud. Protons and neutrons are bound together to form a nucleus by the nuclear force. The diameter of the nucleus is in the range of () for hydrogen (the diameter of a single proton) to about for uranium. These dimensions are much smaller than the diameter of the atom itself (nucleus + electron cloud), by a factor of about 26,634 (uranium atomic radiu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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