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Omicron SARS-CoV-2 Radial Distance Tree 2021-Dec-01
Omicron (; uppercase Ο, lowercase ο, ell, όμικρον) is the 15th letter of the Greek alphabet. This letter is derived from the Phoenician letter ayin: . In classical Greek, omicron represented the close-mid back rounded vowel in contrast to ''omega'' which represented the open-mid back rounded vowel and the digraph ''ου'' which represented the long close-mid back rounded vowel . In modern Greek, both omicron and omega represent the mid back rounded vowel or . Letters that arose from omicron include Roman O and Cyrillic O. The word literally means "little O" (''o mikron'') as opposed to "great O" (''ō mega''). In the system of Greek numerals, omicron has a value of 70. Use In addition to its use as an alphabetic letter, omicron is occasionally used in technical notation, but its use is limited since both upper case and lower case (Ο ο) are indistinguishable from the Latin letter "o" (O o) and difficult to distinguish from the Arabic numeral "zero" (0) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
O (Cyrillic)
O (О о; italics: ) is a letter of the Cyrillic script. O commonly represents the close-mid back rounded vowel , like the pronunciation of in Scottish English "go". History The Cyrillic letter O was derived from the Greek letter Omicron (Ο ο). Form Modern fonts In modern-style typefaces, the Cyrillic letter O looks exactly like the Latin letter O and the Greek letter Omicron . Church Slavonic printed fonts and Slavonic manuscripts Historical typefaces (like ''poluustav'' (semi-uncial), a standard font style for the Church Slavonic typography) and old manuscripts represent several additional glyph variants of Cyrillic O, both for decorative and orthographic (sometimes also "hieroglyphic") purposes, namely: * broad variant (Ѻ/ѻ), used mostly as a word initial letter (see Broad On for more details); * narrow variant, being used now in Synodal Church Slavonic editions as the first element of digraph Oy/oy (see Uk (Cyrillic) for more details), and in the edition ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edmund Landau
Edmund Georg Hermann Landau (14 February 1877 – 19 February 1938) was a German mathematician who worked in the fields of number theory and complex analysis. Biography Edmund Landau was born to a Jewish family in Berlin. His father was Leopold Landau, a gynecologist and his mother was Johanna Jacoby. Landau studied mathematics at the University of Berlin, receiving his doctorate in 1899 and his habilitation (the post-doctoral qualification required to teach in German universities) in 1901. His doctoral thesis was 14 pages long. In 1895, his paper on scoring chess tournaments is the earliest use of eigenvector centrality. Landau taught at the University of Berlin from 1899 to 1909, after which he held a chair at the University of Göttingen. He married Marianne Ehrlich, the daughter of the Nobel Prize-winning biologist Paul Ehrlich, in 1905. At the 1912 International Congress of Mathematicians Landau listed four problems in number theory about primes that he said were parti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Particle Physics
Particle physics or high energy physics is the study of fundamental particles and forces that constitute matter and radiation. The fundamental particles in the universe are classified in the Standard Model as fermions (matter particles) and bosons (force-carrying particles). There are three generations of fermions, but ordinary matter is made only from the first fermion generation. The first generation consists of up and down quarks which form protons and neutrons, and electrons and electron neutrinos. The three fundamental interactions known to be mediated by bosons are electromagnetism, the weak interaction, and the strong interaction. Quarks cannot exist on their own but form hadrons. Hadrons that contain an odd number of quarks are called baryons and those that contain an even number are called mesons. Two baryons, the proton and the neutron, make up most of the mass of ordinary matter. Mesons are unstable and the longest-lived last for only a few hundredths of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Feynman Diagram
In theoretical physics, a Feynman diagram is a pictorial representation of the mathematical expressions describing the behavior and interaction of subatomic particles. The scheme is named after American physicist Richard Feynman, who introduced the diagrams in 1948. The interaction of subatomic particles can be complex and difficult to understand; Feynman diagrams give a simple visualization of what would otherwise be an arcane and abstract formula. According to David Kaiser, "Since the middle of the 20th century, theoretical physicists have increasingly turned to this tool to help them undertake critical calculations. Feynman diagrams have revolutionized nearly every aspect of theoretical physics." While the diagrams are applied primarily to quantum field theory, they can also be used in other fields, such as solid-state theory. Frank Wilczek wrote that the calculations that won him the 2004 Nobel Prize in Physics "would have been literally unthinkable without Feynman diagra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sampi
Sampi (modern: ϡ; ancient shapes: , ) is an archaic letter of the Greek alphabet. It was used as an addition to the classical 24-letter alphabet in some eastern Ionic dialects of ancient Greek in the 6th and 5th centuries BC, to denote some type of a sibilant sound, probably or , and was abandoned when the sound disappeared from Greek. It later remained in use as a numeral symbol for 900 in the alphabetic (" Milesian") system of Greek numerals. Its modern shape, which resembles a π inclining to the right with a longish curved cross-stroke, developed during its use as a numeric symbol in minuscule handwriting of the Byzantine era. Its current name, ''sampi'', originally probably meant "''san pi''", i.e. "like a pi", and is also of medieval origin. The letter's original name in antiquity is not known. It has been proposed that sampi was a continuation of the archaic letter '' san'', which was originally shaped like an M and denoted the sound in some other dialects. Besides ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pi (letter)
Pi (uppercase Π, lowercase π and ϖ; el, πι ) is the sixteenth letter of the Greek alphabet, representing the voiceless bilabial plosive . In the system of Greek numerals it has a value of 80. It was derived from the Phoenician letter Pe (). Letters that arose from pi include Latin P, Cyrillic Pe (П, п), Coptic pi (Ⲡ, ⲡ), and Gothic pairthra (𐍀). Uppercase Pi The uppercase letter Π is used as a symbol for: * In textual criticism, '' Codex Petropolitanus'', a 9th-century uncial codex of the Gospels, now located in St. Petersburg, Russia. * In legal shorthand, it represents a plaintiff. In science and engineering: * The product operator in mathematics, indicated with capital pi notation (in analogy to the use of the capital Sigma as summation symbol). * The osmotic pressure in chemistry. * The viscous stress tensor in continuum mechanics and fluid dynamics. Lowercase Pi The lowercase letter π is used as a symbol for: * The mathematical real transcen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Koppa (letter)
Koppa or qoppa (; as a modern numeral sign: ) is a letter that was used in early forms of the Greek alphabet, derived from Phoenician qoph (). It was originally used to denote the sound, but dropped out of use as an alphabetic character in favor of Kappa (Κ). It has remained in use as a numeral symbol (90) in the system of Greek numerals, although with a modified shape. Koppa is the source of Latin Q, as well as the Cyrillic numeral sign of the same name ( Koppa). Alphabetic In Phoenician, qoph was pronounced ; in Greek, which lacked such a sound, it was instead used for before back vowels Ο, Υ and Ω. In this function, it was borrowed into the Italic alphabets and ultimately into Latin. However, as the sound had two redundant spellings, koppa was eventually replaced by kappa (Κ) in Greek. It remained in use as a letter in some Doric regions into the 5th century BC. The koppa was used as a symbol for the city of Corinth, which had the early spelling of . Numer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digamma
Digamma or wau (uppercase: Ϝ, lowercase: ϝ, numeral: ϛ) is an archaic letter of the Greek alphabet. It originally stood for the sound but it has remained in use principally as a Greek numeral for 6. Whereas it was originally called ''waw'' or ''wau'', its most common appellation in classical Greek is ''digamma''; as a numeral, it was called ''episēmon'' during the Byzantine era and is now known as '' stigma'' after the Byzantine ligature combining σ-τ as ϛ. Digamma or wau was part of the original archaic Greek alphabet as initially adopted from Phoenician. Like its model, Phoenician waw, it represented the voiced labial-velar approximant and stood in the 6th position in the alphabet between epsilon and zeta. It is the consonantal doublet of the vowel letter upsilon (), which was also derived from waw but was placed near the end of the Greek alphabet. Digamma or wau is in turn the ancestor of the Latin letter F. As an alphabetic letter, it is attested in archaic a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zeta
Zeta (, ; uppercase Ζ, lowercase ζ; grc, ζῆτα, el, ζήτα, label= Demotic Greek, classical or ''zē̂ta''; ''zíta'') is the sixth letter of the Greek alphabet. In the system of Greek numerals, it has a value of 7. It was derived from the Phoenician letter zayin . Letters that arose from zeta include the Roman Z and Cyrillic З. Name Unlike the other Greek letters, this letter did not take its name from the Phoenician letter from which it was derived; it was given a new name on the pattern of beta, eta and theta. The word ''zeta'' is the ancestor of ''zed'', the name of the Latin letter Z in Commonwealth English. Swedish and many Romanic languages (such as Italian and Spanish) do not distinguish between the Greek and Roman forms of the letter; "''zeta''" is used to refer to the Roman letter Z as well as the Greek letter. Uses Letter The letter ζ represents the voiced alveolar fricative in Modern Greek Modern Greek (, , or , ''Kiní Neoellinikí Gl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epsilon
Epsilon (, ; uppercase , lowercase or lunate ; el, έψιλον) is the fifth letter of the Greek alphabet, corresponding phonetically to a mid front unrounded vowel or . In the system of Greek numerals it also has the value five. It was derived from the Phoenician letter He . Letters that arose from epsilon include the Roman E, Ë and Ɛ, and Cyrillic Е, È, Ё, Є and Э. The name of the letter was originally (), but it was later changed to ( 'simple e') in the Middle Ages to distinguish the letter from the digraph , a former diphthong that had come to be pronounced the same as epsilon. The uppercase form of epsilon is identical to Latin E but has its own code point in Unicode: . The lowercase version has two typographical variants, both inherited from medieval Greek handwriting. One, the most common in modern typography and inherited from medieval minuscule, looks like a reversed number "3" and is encoded . The other, also known as lunate or uncial epsilon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geometry
Geometry (; ) is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space such as the distance, shape, size, and relative position of figures. A mathematician who works in the field of geometry is called a ''geometer''. Until the 19th century, geometry was almost exclusively devoted to Euclidean geometry, which includes the notions of point, line, plane, distance, angle, surface, and curve, as fundamental concepts. During the 19th century several discoveries enlarged dramatically the scope of geometry. One of the oldest such discoveries is Carl Friedrich Gauss' ("remarkable theorem") that asserts roughly that the Gaussian curvature of a surface is independent from any specific embedding in a Euclidean space. This implies that surfaces can be studied ''intrinsically'', that is, as stand-alone spaces, and has been expanded into the theory of manifolds and Riemannian geometry. Later in the 19th century, it appeared that geometries ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euclid's Elements
The ''Elements'' ( grc, Στοιχεῖα ''Stoikheîa'') is a mathematical treatise consisting of 13 books attributed to the ancient Greek mathematician Euclid in Alexandria, Ptolemaic Egypt 300 BC. It is a collection of definitions, postulates, propositions (theorems and constructions), and mathematical proofs of the propositions. The books cover plane and solid Euclidean geometry, elementary number theory, and incommensurable lines. ''Elements'' is the oldest extant large-scale deductive treatment of mathematics. It has proven instrumental in the development of logic and modern science, and its logical rigor was not surpassed until the 19th century. Euclid's ''Elements'' has been referred to as the most successful and influential textbook ever written. It was one of the very earliest mathematical works to be printed after the invention of the printing press and has been estimated to be second only to the Bible in the number of editions published since the first printing i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
