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1931 In Science
The year 1931 in science and technology involved some significant events, listed below. Astronomy * French astronomer Bernard Lyot invents the coronagraph. Chemistry * November 26 – Harold Urey and associates at Columbia University discover deuterium by the fractional distillation of liquid hydrogen, leading to demonstration of the existence of heavy water. * Erich Hückel proposes Hückel's rule, which explains when a planar ring molecule will have aromatic properties. * The first aerogel is created by Steven Kistler. Earth sciences * Modified Mercalli intensity scale introduced as a seismic scale for earthquakes in the United States. History of science * Het Nederlandsch Historisch Natuurwetenschappelijk Museum ("The Dutch Historical Museum of the Natural Sciences") opens in Leiden. Mathematics * January – Kurt Gödel's " On Formally Undecidable Propositions..." is published in ''Monatshefte für Mathematik''. Physics * Ernst Ruska and Max Knoll build the first prot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Physical Chemistry
''The Journal of Physical Chemistry A'' is a scientific journal which reports research on the chemistry of molecules - including their dynamics, spectroscopy, kinetics, structure, bonding, and quantum chemistry. It is published weekly by the American Chemical Society. Before 1997 the title was simply ''Journal of Physical Chemistry''. Owing to the ever-growing amount of research in the area, in 1997 the journal was split into ''Journal of Physical Chemistry A'' (molecular theoretical and experimental physical chemistry) and '' The Journal of Physical Chemistry B'' (solid state, soft matter, liquids, etc.). Beginning in 2007, the latter underwent a further split, with '' The Journal of Physical Chemistry C'' now being dedicated to nanotechnology, molecular electronics, and related subjects. According to the ''Journal Citation Reports'', the journal have an impact factor of 2.7 for 2023. Editors-in-chief *1896–1932 Wilder Dwight Bancroft, Joseph E. Trevor *1933–1951 S. C. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Monopole
In particle physics, a magnetic monopole is a hypothetical particle that is an isolated magnet with only one magnetic pole (a north pole without a south pole or vice versa). A magnetic monopole would have a net north or south "magnetic charge". Modern interest in the concept stems from high-energy physics, particle theories, notably the grand unified theory, grand unified and superstring theory, superstring theories, which predict their existence. The known elementary particles that have electric charge are electric monopoles. Magnetism in bar magnets and electromagnets is not caused by magnetic monopoles, and indeed, there is no known experimental or observational evidence that magnetic monopoles exist. A magnetic monopole is not necessarily an elementary particle, and models for magnetic monopole production can include (but are not limited to) Spin (physics), spin-0 monopoles or spin-1 massive vector mesons. The term "magnetic monopole" only refers to the nature of the particle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paul Dirac
Paul Adrien Maurice Dirac ( ; 8 August 1902 – 20 October 1984) was an English mathematician and Theoretical physics, theoretical physicist who is considered to be one of the founders of quantum mechanics. Dirac laid the foundations for both quantum electrodynamics and quantum field theory. He was the Lucasian Professor of Mathematics at the University of Cambridge and a professor of physics at Florida State University. Dirac shared the 1933 Nobel Prize in Physics with Erwin Schrödinger for "the discovery of new productive forms of atomic theory". Dirac graduated from the University of Bristol with a first class honours Bachelor of Science degree in electrical engineering in 1921, and a first class honours Bachelor of Arts degree in mathematics in 1923. Dirac then graduated from the University of Cambridge with a PhD in physics in 1926, writing the first ever thesis on quantum mechanics. Dirac made fundamental contributions to the early development of both quantum mechanic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron Microscope
An electron microscope is a microscope that uses a beam of electrons as a source of illumination. It uses electron optics that are analogous to the glass lenses of an optical light microscope to control the electron beam, for instance focusing it to produce magnified images or electron diffraction patterns. As the wavelength of an electron can be up to 100,000 times smaller than that of visible light, electron microscopes have a much higher Angular resolution, resolution of about 0.1 nm, which compares to about 200 nm for optical microscope, light microscopes. ''Electron microscope'' may refer to: * Transmission electron microscopy, Transmission electron microscope (TEM) where swift electrons go through a thin sample * Scanning transmission electron microscopy, Scanning transmission electron microscope (STEM) which is similar to TEM with a scanned electron probe * Scanning electron microscope (SEM) which is similar to STEM, but with thick samples * Electron microprobe sim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Max Knoll
Max Knoll (17 July 1897 – 6 November 1969) was a German electrical engineer and co-inventor of the electron microscope. Knoll was born in Wiesbaden and studied at the University of Munich and at the Technischen Hochschulen in Munich and Berlin-Charlottenburg, where he obtained his doctorate in the Institute for High Voltage Technology. In 1927 he became the leader of the electron research group there, where he and his co-worker, Ernst Ruska, invented the electron microscope in 1931. In April 1932, Knoll joined Telefunken in Berlin to do developmental work in the field of television design. He was also a private lecturer in Berlin. After World War II, Knoll joined the University of Munich as an extraordinary professor and director of the Institute for Electromedicine. He moved to the USA in 1948, to work at the Department of Electrical Engineering at Princeton University. In 1956 he returned to Munich and engaged in a series of experiments at the Technische Hochschule, i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ernst Ruska
Ernst August Friedrich Ruska (; 25 December 1906 – 27 May 1988) was a German physicist who won the Nobel Prize in Physics in 1986 for his work in electron optics, including the design of the first electron microscope. Life and career Ernst Ruska was born in Heidelberg, Germany. He was educated at the Technical University of Munich from 1925 to 1927 and then entered ''Technische Hochschule Berlin'' (now Technische Universität Berlin), where he posited that microscopes using electrons, with wavelengths 1000 times shorter than those of light, could provide a more detailed picture of an object than a microscope utilizing light, in which magnification is limited by the size of the wavelengths. In 1931, he demonstrated that a magnetic coil could act as an electron lens, and used several coils in a series to build the first electron microscope in 1933. After completing his PhD in 1933, Ruska continued to work in the field of electron optics, first at Fernseh AG in Berlin-Zehlendo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
On Formally Undecidable Propositions Of Principia Mathematica And Related Systems
"Über formal unentscheidbare Sätze der Principia Mathematica und verwandter Systeme I" ("On Formally Undecidable Propositions of Principia Mathematica and Related Systems I") is a paper in mathematical logic by Kurt Gödel. Submitted November 17, 1930, it was originally published in German in the 1931 volume of '' Monatshefte für Mathematik und Physik.'' Several English translations have appeared in print, and the paper has been included in two collections of classic mathematical logic papers. The paper contains Gödel's incompleteness theorems, now fundamental results in logic that have many implications for consistency proofs in mathematics. The paper is also known for introducing new techniques that Gödel invented to prove the incompleteness theorems. Outline and key results The main results established are Gödel's first and second incompleteness theorems, which have had an enormous impact on the field of mathematical logic. These appear as theorems VI and XI, respect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kurt Gödel
Kurt Friedrich Gödel ( ; ; April 28, 1906 – January 14, 1978) was a logician, mathematician, and philosopher. Considered along with Aristotle and Gottlob Frege to be one of the most significant logicians in history, Gödel profoundly influenced scientific and philosophical thinking in the 20th century (at a time when Bertrand Russell,For instance, in their "Principia Mathematica' (''Stanford Encyclopedia of Philosophy'' edition). Alfred North Whitehead, and David Hilbert were using logic and set theory to investigate the foundations of mathematics), building on earlier work by Frege, Richard Dedekind, and Georg Cantor. Gödel's discoveries in the foundations of mathematics led to the proof of his completeness theorem in 1929 as part of his dissertation to earn a doctorate at the University of Vienna, and the publication of Gödel's incompleteness theorems two years later, in 1931. The incompleteness theorems address limitations of formal axiomatic systems. In parti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leiden
Leiden ( ; ; in English language, English and Archaism, archaic Dutch language, Dutch also Leyden) is a List of cities in the Netherlands by province, city and List of municipalities of the Netherlands, municipality in the Provinces of the Netherlands, province of South Holland, Netherlands. The municipality of Leiden has a population of 127,046 (31 January 2023), but the city forms one densely connected agglomeration with its suburbs Oegstgeest, Leiderdorp, Voorschoten and Zoeterwoude with 215,602 inhabitants. The Statistics Netherlands, Netherlands Central Bureau of Statistics (CBS) further includes Katwijk in the agglomeration which makes the total population of the Leiden urban agglomeration 282,207 and in the larger Leiden urban area also Teylingen, Noordwijk, and Noordwijkerhout are included with in total 365,913 inhabitants. Leiden is located on the Oude Rijn (Utrecht and South Holland), Oude Rijn, at a distance of some from The Hague to its south and some from Amsterdam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Museum Boerhaave
Rijksmuseum Boerhaave is a museum of the history of science and medicine, based in Leiden, Netherlands. The museum hosts a collection of historical scientific instruments from all disciplines, but mainly from medicine, physics, and astronomy. The museum is located in a building that was originally a convent in central Leiden. It includes a reconstructed traditional anatomical theatre. It also has many galleries that include the apparatus with which Heike Kamerlingh Onnes first liquefied helium (in Leiden), the electromagnet equipment used by Wander Johannes de Haas (a Leiden physicist) for his low-temperature research, and an example of the Leiden jar, among many other objects in the extensive collection. The museum is named after Herman Boerhaave, a Dutch physician and botanist who was famous in Europe for his teaching at Leiden University, Leiden and lived to a great age, receiving brilliant students from all over Europe, including Peter the Great, Voltaire and Carl Linnaeus, L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earthquake
An earthquakealso called a quake, tremor, or tembloris the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they cannot be felt, to those violent enough to propel objects and people into the air, damage critical infrastructure, and wreak destruction across entire cities. The seismic activity of an area is the frequency, type, and size of earthquakes experienced over a particular time. The seismicity at a particular location in the Earth is the average rate of seismic energy release per unit volume. In its most general sense, the word ''earthquake'' is used to describe any seismic event that generates seismic waves. Earthquakes can occur naturally or be induced by human activities, such as mining, fracking, and nuclear weapons testing. The initial point of rupture is called the hypocenter or focus, while the ground level directly above it is the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
