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Marietta Kurz
Marietta Kurz was a physicist and the first person to find evidence of the subatomic particles known as mesons, specifically pions. Kurz was employed by Cecil Powell's research team at the University of Bristol as a "scanner", tasked to search for the tracks left by subatomic events recorded in photographic plates. The plates had been lofted to high altitudes to increase the possibility of recording decay events from the shower of particles from cosmic rays interacting with the nuclei of atoms in the atmosphere. On 7 March 1947, while inspecting a plate, she noticed through her microscope a track of silver particles that showed a meson stopping and another one continuing from where the first had terminated. She recorded this with a sketch in her notebook and the words "double meson" in capitals. Powell and Hugh Muirhead immediately realised the significance. Though the decay event was clear, the resultant track was incomplete, having left the edge of the plate. Following instructio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meson
In particle physics, a meson ( or ) is a type of hadronic subatomic particle composed of an equal number of quarks and antiquarks, usually one of each, bound together by the strong interaction. Because mesons are composed of quark subparticles, they have a meaningful physical size, a diameter of roughly one femtometre (10 m), which is about 0.6 times the size of a proton or neutron. All mesons are unstable, with the longest-lived lasting for only a few hundredths of a microsecond. Heavier mesons decay to lighter mesons and ultimately to stable electrons, neutrinos and photons. Outside the nucleus, mesons appear in nature only as short-lived products of very high-energy collisions between particles made of quarks, such as cosmic rays (high-energy protons and neutrons) and baryonic matter. Mesons are routinely produced artificially in cyclotrons or other particle accelerators in the collisions of protons, antiprotons, or other particles. Higher-energy (more massive) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pion
In particle physics, a pion (or a pi meson, denoted with the Greek letter pi: ) is any of three subatomic particles: , , and . Each pion consists of a quark and an antiquark and is therefore a meson. Pions are the lightest mesons and, more generally, the lightest hadrons. They are unstable, with the charged pions and decaying after a mean lifetime of 26.033 nanoseconds ( seconds), and the neutral pion decaying after a much shorter lifetime of 85 attoseconds ( seconds). Charged pions most often decay into muons and muon neutrinos, while neutral pions generally decay into gamma rays. The exchange of virtual pions, along with vector, rho and omega mesons, provides an explanation for the residual strong force between nucleons. Pions are not produced in radioactive decay, but commonly are in high-energy collisions between hadrons. Pions also result from some matter–antimatter annihilation events. All types of pions are also produced in natural processes wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cecil Powell
Cecil Frank Powell, FRS (5 December 1903 – 9 August 1969) was a British physicist, and Nobel Prize in Physics laureate for heading the team that developed the photographic method of studying nuclear processes and for the resulting discovery of the pion (pi-meson), a subatomic particle. Personal life Powell was born in Tonbridge, Kent, England, the son Frank and Elizabeth Caroline (née Bisacre) Powell. His father was a gunsmith. He was educated at a local primary school before gaining a scholarship to the Judd School, Tonbridge. Following this he attended Sidney Sussex College, Cambridge, graduating in 1925 in Natural Sciences. After completing his bachelor's degree he worked at the Cavendish Laboratory, Cambridge, under C.T.R. Wilson and Lord Rutherford, conducting research into condensation phenomena, and gaining his PhD in Physics in 1929. In 1932 Powell married Isobel Artner (1907-1995), and the couple had two daughters, Jane and Annie. Professional life In 1928 he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Bristol
, mottoeng = earningpromotes one's innate power (from Horace, ''Ode 4.4'') , established = 1595 – Merchant Venturers School1876 – University College, Bristol1909 – received royal charter , type = Public red brick research university , endowment = £91.3 million (2021) , budget = £752.0 million (2020–21) , chancellor = Paul Nurse , vice_chancellor = Professor Evelyn Welch , head_label = Visitor , head = Rt Hon. Penny Mordaunt MP , academic_staff = 3,385 (2020) , students = () , undergrad = () , postgrad = () , city = Bristol , country = England , coor = , campus = Urban , free_label = Students' Union , free = University of Bristol Union , colours = ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cosmic Ray
Cosmic rays are high-energy particles or clusters of particles (primarily represented by protons or atomic nuclei) that move through space at nearly the speed of light. They originate from the Sun, from outside of the Solar System in our own galaxy, and from distant galaxies. Upon impact with Earth's atmosphere, cosmic rays produce showers of secondary particles, some of which reach the surface, although the bulk is deflected off into space by the magnetosphere or the heliosphere. Cosmic rays were discovered by Victor Hess in 1912 in balloon experiments, for which he was awarded the 1936 Nobel Prize in Physics. Direct measurement of cosmic rays, especially at lower energies, has been possible since the launch of the first satellites in the late 1950s. Particle detectors similar to those used in nuclear and high-energy physics are used on satellites and space probes for research into cosmic rays. Data from the Fermi Space Telescope (2013) have been interpreted as evidenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hugh Muirhead
Hugh Muirhead (1925 – 19 January 2007) was a British nuclear physicist and the last surviving author of the scientific paper announcing the discovery of the pion, a particle predicted by Hideki Yukawa. Muirhead did his PhD studies at the University of Bristol, where he, César Lattes and Giuseppe Occhialini, were part of Cecil Powell's group trying to confirm the existence of pions. Evidence was eventually found on 7 March 1947 by two of the group's technical team, Marietta Kurz and Irene Roberts. A paper was submitted to the journal ''Nature'' and published the same year. In 1950, Powell was awarded the Nobel Prize for the discovery. After gaining his PhD, Muirhead moved to the University of Glasgow and then the University of Liverpool in 1957, where he spent the rest of his career. Under his direction at Liverpool, it was experimentally confirmed that parity was violated in muon capture. He became a world authority on antiproton physics. As well as dozens of scientific pap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nature (journal)
''Nature'' is a British weekly scientific journal founded and based in London, England. As a multidisciplinary publication, ''Nature'' features peer-reviewed research from a variety of academic disciplines, mainly in science and technology. It has core editorial offices across the United States, continental Europe, and Asia under the international scientific publishing company Springer Nature. ''Nature'' was one of the world's most cited scientific journals by the Science Edition of the 2019 ''Journal Citation Reports'' (with an ascribed impact factor of 42.778), making it one of the world's most-read and most prestigious academic journals. , it claimed an online readership of about three million unique readers per month. Founded in autumn 1869, ''Nature'' was first circulated by Norman Lockyer and Alexander Macmillan as a public forum for scientific innovations. The mid-20th century facilitated an editorial expansion for the journal; ''Nature'' redoubled its efforts in exp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
César Lattes
Cesare Mansueto Giulio Lattes (11 July 1924 – 8 March 2005), also known as César Lattes, was a Brazilian experimental physicist, one of the discoverers of the pion, a composite subatomic particle made of a quark and an antiquark. Life Lattes was born to a family of Italian immigrants in Curitiba, Paraná Brazil. He did his first studies there and also in São Paulo. He then went to the University of São Paulo, graduating in 1943, in mathematics and physics. He was part of an initial group of young Brazilian physicists who worked under European teachers such as Gleb Wataghin and Giuseppe Occhialini. Lattes was considered the most brilliant of those and was noted at a very young age as a bold researcher. His colleagues, who also became important Brazilian scientists, were Oscar Sala, Mário Schenberg, Roberto Salmeron, Marcelo Damy de Souza Santos and Jayme Tiomno. At the age of 25, he was one of the founders of the Brazilian Center for Physical Research (''Centro Brasileir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Giuseppe Occhialini
Giuseppe Paolo Stanislao "Beppo" Occhialini ForMemRS (; 5 December 1907 – 30 December 1993) was an Italian physicist who contributed to the discovery of the pion or pi-meson decay in 1947 with César Lattes and Cecil Frank Powell, the latter winning the Nobel Prize in Physics for this work. At the time of this discovery, they were all working at the H. H. Wills Laboratory of the University of Bristol. The X-ray satellite SAX was named BeppoSAX in his honour after its launch in 1996. Biography His father was the physicist Raffaele Augusto Occhialini (1878–1951), a pioneer in the fields of spectroscopy and electronics theory. Giuseppe Paolo Stanislao Occhialini graduated at Florence in 1929. In 1932, he collaborated in the discovery of the positron in cosmic rays at the Cavendish Laboratory of Cambridge, under the leadership of Patrick Blackett, using cloud chambers. He returned in Italy in 1934, where he suffered from the political climate generated by fascism. Thus, fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nobel Prize
The Nobel Prizes ( ; sv, Nobelpriset ; no, Nobelprisen ) are five separate prizes that, according to Alfred Nobel's will of 1895, are awarded to "those who, during the preceding year, have conferred the greatest benefit to humankind." Alfred Nobel was a Swedish chemist, engineer, and industrialist most famously known for the invention of dynamite. He died in 1896. In his will, he bequeathed all of his "remaining realisable assets" to be used to establish five prizes which became known as "Nobel Prizes." Nobel Prizes were first awarded in 1901. Nobel Prizes are awarded in the fields of Physics, Chemistry, Physiology or Medicine, Literature, and Peace (Nobel characterized the Peace Prize as "to the person who has done the most or best to advance fellowship among nations, the abolition or reduction of standing armies, and the establishment and promotion of peace congresses"). In 1968, Sveriges Riksbank (Sweden's central bank) funded the establishment of the Prize in Economi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Women Physicists
A woman is an adult female human. Prior to adulthood, a female human is referred to as a girl (a female child or adolescent). The plural ''women'' is sometimes used in certain phrases such as "women's rights" to denote female humans regardless of age. Typically, women inherit a pair of X chromosomes, one from each parent, and are capable of pregnancy and giving birth from puberty until menopause. More generally, sex differentiation of the female fetus is governed by the lack of a present, or functioning, SRY-gene on either one of the respective sex chromosomes. Female anatomy is distinguished from male anatomy by the female reproductive system, which includes the ovaries, fallopian tubes, uterus, vagina, and vulva. A fully developed woman generally has a wider pelvis, broader hips, and larger breasts than an adult man. Women have significantly less facial and other body hair, have a higher body fat composition, and are on average shorter and less muscular than men. Thro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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