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Tendril Perversion
Tendril perversion is a geometric phenomenon sometimes observed in helical structures in which the direction of the helix transitions between left-handed and right-handed. Such a reversal of chirality is commonly seen in helical plant tendrils and telephone handset cords. The phenomenon was known to Charles Darwin, who wrote in 1865, The term "tendril perversion" was coined by Alain Goriely and Michael Tabor in 1998 based on the word ''perversion'' found in the 19th century science literature. "Perversion" is a transition from one chirality to another and was known to James Clerk Maxwell, who attributed it to topologist J. B. Listing. Tendril perversion can be viewed as an example of spontaneous symmetry breaking, in which the strained structure of the tendril adopts a configuration of minimum energy while preserving zero overall twist. Tendril perversion has been studied both experimentally and theoretically. Gerbode et al. have made experimental studies of the coiling ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PSM V17 D663 A Caught Tendril Of Bryonia Dioica
PSM, an acronym, may refer to: Organizations * Sepaktakraw Association of Malaysia ( ms, Persatuan Sepaktakraw Malaysia; PSM), a national governing body in Malaysia. * Pakistan School Muscat, a Pakistani co-educational institute in Oman * Palestine Solidarity Movement, a student organization in the United States * Panhellenic Socialist Movement, a centre-left party in Greece * Parti Sosialis Malaysia, a socialist political party in Malaysia * PlayStation: The Official Magazine, a magazine originally known as PlayStation Magazine or PSM * Ponce School of Medicine, a post-graduate medical school located in Ponce, Puerto Rico * Power Systems Mfg, a subsidiary of Alstom, specializing in aftermarket gas turbine servicing for power generating industry. * ''Poznańska Spółdzielnia Mieszkaniowa'', a housing cooperative administering most of the Piątkowo district of Poznań, Poland * PSM3, a UK video game magazine specializing in Sony consoles * PSM Makassar, a football club that pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Topologist
In mathematics, topology (from the Greek words , and ) is concerned with the properties of a geometric object that are preserved under continuous deformations, such as stretching, twisting, crumpling, and bending; that is, without closing holes, opening holes, tearing, gluing, or passing through itself. A topological space is a set endowed with a structure, called a ''topology'', which allows defining continuous deformation of subspaces, and, more generally, all kinds of continuity. Euclidean spaces, and, more generally, metric spaces are examples of a topological space, as any distance or metric defines a topology. The deformations that are considered in topology are homeomorphisms and homotopies. A property that is invariant under such deformations is a topological property. Basic examples of topological properties are: the dimension, which allows distinguishing between a line and a surface; compactness, which allows distinguishing between a line and a circle; connectedne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Curves
A curve is a geometrical object in mathematics. Curve(s) may also refer to: Arts, entertainment, and media Music * Curve (band), an English alternative rock music group * ''Curve'' (album), a 2012 album by Our Lady Peace * "Curve" (song), a 2017 song by Gucci Mane featuring The Weeknd * ''Curve'', a 2001 album by Doc Walker * "Curve", a song by John Petrucci from ''Suspended Animation'', 2005 * "Curve", a song by Cam'ron from the album '' Crime Pays'', 2009 Periodicals * ''Curve'' (design magazine), an industrial design magazine * ''Curve'' (magazine), a U.S. lesbian magazine Other uses in arts, entertainment, and media * ''Curve'' (film), a 2015 film * BBC Two 'Curve' idents, various animations based around a curve motif Brands and enterprises *Curve (payment card), a payment card that aggregates multiple payment cards * Curve (theatre), a theatre in Leicester, United Kingdom * Curve, fragrance by Liz Claiborne * BlackBerry Curve, a series of phones from Research in Motio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helices
A helix () is a shape like a corkscrew or spiral staircase. It is a type of smooth space curve with tangent lines at a constant angle to a fixed axis. Helices are important in biology, as the DNA molecule is formed as two intertwined helices, and many proteins have helical substructures, known as alpha helices. The word ''helix'' comes from the Greek word ''ἕλιξ'', "twisted, curved". A "filled-in" helix – for example, a "spiral" (helical) ramp – is a surface called ''helicoid''. Properties and types The ''pitch'' of a helix is the height of one complete helix turn, measured parallel to the axis of the helix. A double helix consists of two (typically congruent) helices with the same axis, differing by a translation along the axis. A circular helix (i.e. one with constant radius) has constant band curvature and constant torsion. A ''conic helix'', also known as a ''conic spiral'', may be defined as a spiral on a conic surface, with the distance to the apex an expo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemihelix
A hemihelix is a curved geometric shape consisting of a series of helices with alternating chirality, connected by a perversion Perversion is a form of human behavior which deviates from what is considered to be orthodox or normal. Although the term ''perversion'' can refer to a variety of forms of deviation, it is most often used to describe sexual behaviors that are c ... at the reversals. The formation of hemihelices with periodic distributions of perversions in slender structures is understood in terms of competing buckling instabilities generated by in-plane stresses. References Helices Geometric shapes Curves Articles containing video clips {{physics-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helical Growth
Helical growth is when cells or organs expand, resulting in helical shaped cells or organs and typically including the breakage of symmetry. This is seen in fungi, algae, and other higher plant cells or organs. Helical growth can occur naturally, such as in tendrils or in twining plants. Asymmetry can be caused by changes in pectin or through mutation and result in left- or right-handed helices. Tendril perversion, during which a tendril curves in opposite directions at each end, is seen in many cases. The helical growth of twining plants is based on the circumnutational movement, or circular growth, of stems. Most twining plans have right-handed helices regardless of the plant's growth hemisphere. Helical growth in single cells, such as the fungi genus ''Phycomyces'' or the algae genus '' Nitella'', is thought to be caused by a helical arrangement of structural biological material in the cell wall. In mutant thale cress, helical growth is seen at the organ level. Analysis s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cucumber
Cucumber (''Cucumis sativus'') is a widely-cultivated Vine#Horticultural climbing plants, creeping vine plant in the Cucurbitaceae family that bears usually cylindrical Fruit, fruits, which are used as culinary vegetables.Cucumber " ''Encyclopædia Britannica''. [1998] 2019. Considered an annual plant, there are three main varieties of cucumber—slicing, Pickled cucumber, pickling, and Seedless fruit, seedless—within which several cultivars have been created. The cucumber originates from South Asia, but now grows on most continents, as many different types of cucumber are traded on the global market. In North America, the term ''wild cucumber'' refers to plants in the Genus, genera ''Echinocystis'' and ''Marah (plant), Marah'', though the two are not closely related. Description The cucumber is a Vine# ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minimum Total Potential Energy Principle
The minimum total potential energy principle is a fundamental concept used in physics and engineering. It dictates that at low temperatures a structure or body shall deform or displace to a position that (locally) minimizes the total potential energy, with the lost potential energy being converted into kinetic energy (specifically heat). Some examples * A free proton and free electron will tend to combine to form the lowest energy state (the ground state) of a hydrogen atom, the most stable configuration. This is because that state's energy is 13.6 electron volts (eV) lower than when the two particles separated by an infinite distance. The dissipation in this system takes the form of spontaneous emission of electromagnetic radiation, which increases the entropy of the surroundings. * A rolling ball will end up stationary at the bottom of a hill, the point of minimum potential energy. The reason is that as it rolls downward under the influence of gravity, friction produced by its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spontaneous Symmetry Breaking
Spontaneous symmetry breaking is a spontaneous process of symmetry breaking, by which a physical system in a symmetric state spontaneously ends up in an asymmetric state. In particular, it can describe systems where the equations of motion or the Lagrangian obey symmetries, but the lowest-energy vacuum solutions do not exhibit that same symmetry. When the system goes to one of those vacuum solutions, the symmetry is broken for perturbations around that vacuum even though the entire Lagrangian retains that symmetry. Overview By definition, spontaneous symmetry breaking requires the existence of physical laws (e.g. quantum mechanics) which are invariant under a symmetry transformation (such as translation or rotation), so that any pair of outcomes differing only by that transformation have the same probability distribution. For example if measurements of an observable at any two different positions have the same probability distribution, the observable has translational symmetry. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Clerk Maxwell
James Clerk Maxwell (13 June 1831 – 5 November 1879) was a Scottish mathematician and scientist responsible for the classical theory of electromagnetic radiation, which was the first theory to describe electricity, magnetism and light as different manifestations of the same phenomenon. Maxwell's equations for electromagnetism have been called the " second great unification in physics" where the first one had been realised by Isaac Newton. With the publication of "A Dynamical Theory of the Electromagnetic Field" in 1865, Maxwell demonstrated that electric and magnetic fields travel through space as waves moving at the speed of light. He proposed that light is an undulation in the same medium that is the cause of electric and magnetic phenomena. (This article accompanied an 8 December 1864 presentation by Maxwell to the Royal Society. His statement that "light and magnetism are affections of the same substance" is at page 499.) The unification of light and electrical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cucurbita Pepo 02 Ies
''Cucurbita'' (Latin for gourd) is a genus of herbaceous fruits in the gourd family, Cucurbitaceae (also known as ''cucurbits'' or ''cucurbi''), native to the Andes and Mesoamerica. Five edible species are grown and consumed for their flesh and seeds. They are variously known as squash, pumpkin, or gourd, depending on species, variety, and local parlance. Other kinds of gourd, also called bottle-gourds, are native to Africa and belong to the genus ''Lagenaria'', which is in the same family and subfamily as ''Cucurbita'', but in a different tribe. These other gourds are used as utensils or vessels, and their young fruits are eaten much like those of the ''Cucurbita'' species. Most ''Cucurbita'' species are herbaceous vines that grow several meters in length and have tendrils, but non-vining "bush" cultivars of ''C. pepo'' and ''C. maxima'' have also been developed. The yellow or orange flowers on a ''Cucurbita'' plant are of two types: female and male. The female flow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alain Goriely
Alain Goriely FRS is a Belgian mathematician, currently holding the statutory professorship (chair) of mathematical modelling at the University of Oxford, Mathematical Institute. He is director of the Oxford Centre for Industrial Mathematics (OCIAM), of the International Brain and Mechanics Lab (IBMTL) and Professorial Fellow at St Catherine's College, Oxford. At the Mathematical Institute, he was the director of external relations and public engagement, from 2013 until 2022, initiating the Oxford Mathematics series of public lectures. In 2022, he was elected to the Royal Society. Biography Born and raised in Brussels, Alain Goriely obtained his B.Sc. in 1989 and Ph.D. in 1994 from the Université Libre de Bruxelles where he became lecturer in the Mathematics Department. Shortly after, he moved to the University of Arizona to take the positions of Research Associate (1994-1997), Assistant Professor (1998-2002), Associate Professor (2002-2007) and Professor (2007-2010). In Tu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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