Inversion or inversions may refer to:

Arts

* , a French gay magazine (1924/1925) * ''Inversion'' (artwork), a 2005 temporary sculpture in Houston, Texas *

Inversion (music) In music theory, an inversion is a type of change to intervals, chords, voices (in counterpoint), and melodies. In each of these cases, "inversion" has a distinct but related meaning. The concept of inversion also plays an important role in m ...

, a term with various meanings in music theory and musical set theory * ''Inversions'' (novel) by Iain M. Banks * ''Inversion'' (video game), a 2012 third person shooter for Xbox 360, PlayStation 3, and PC * ''Inversions'' (EP), the 2014 extended play album by American rock music ensemble The Colourist * ''Inversions'' (album), a 2019 album by Belinda O'Hooley * ''Inversion'' (film), a 2016 Iranian film

Linguistics and language

Inversion (linguistics) In linguistics, inversion is any of several grammatical constructions where two expressions switch their canonical order of appearance, that is, they invert. There are several types of subject-verb inversion in English: ''locative inversion'', ''d ...

, grammatical constructions where two expressions switch their order of appearance * Inversion (prosody), the reversal of the order of a foot's elements in poetry *

Anastrophe Anastrophe (from the el, ἀναστροφή, ''anastrophē'', "a turning back or about") is a figure of speech in which the normal word order of the subject, the verb, and the object is changed. For example, subject–verb–object ("I like ...

, a figure of speech also known as an ''inversion''

Mathematics and logic

* Involution (mathematics), a function that is its own inverse (when applied twice, the starting value is obtained) *

Inversion (discrete mathematics) In computer science and discrete mathematics, an inversion in a sequence is a pair of elements that are out of their natural order. Definitions Inversion Let \pi be a permutation. There is an inversion of \pi between i and j if i \pi(j). ...

, any item that is out of order in a sequence *

Inverse element In mathematics, the concept of an inverse element generalises the concepts of opposite () and reciprocal () of numbers. Given an operation denoted here , and an identity element denoted , if , one says that is a left inverse of , and that is ...

* Inversive geometry#Circle inversion, a transformation of the Euclidean plane that maps generalized circles to generalized circles * Inversion in a point, or

point reflection In geometry, a point reflection (point inversion, central inversion, or inversion through a point) is a type of isometry of Euclidean space. An object that is invariant under a point reflection is said to possess point symmetry; if it is invari ...

, a kind of isometric (distance-preserving) transformation in a Euclidean space *

Inversion transformation In mathematical physics, inversion transformations are a natural extension of Poincaré transformations to include all conformal one-to-one transformations on coordinate space-time. They are less studied in physics because unlike the rotations ...

, a conformal transformation (one which preserves angles of intersection) * Method of inversion, the image of a harmonic function in a sphere (or plane); see Method of image charges *

Multiplicative inverse In mathematics, a multiplicative inverse or reciprocal for a number ''x'', denoted by 1/''x'' or ''x''−1, is a number which when multiplied by ''x'' yields the multiplicative identity, 1. The multiplicative inverse of a fraction ''a''/ ...

, the reciprocal of a number (or any other type of element for which a multiplication function is defined) *

Matrix inversion In linear algebra, an -by- square matrix is called invertible (also nonsingular or nondegenerate), if there exists an -by- square matrix such that :\mathbf = \mathbf = \mathbf_n \ where denotes the -by- identity matrix and the multiplicati ...

, an operation on a matrix that results in its multiplicative inverse *

Model inversion An inverse problem in science is the process of calculating from a set of observations the causal factors that produced them: for example, calculating an image in X-ray computed tomography, source reconstruction in acoustics, or calculating the ...

Set inversion In mathematics, set inversion is the problem of characterizing the preimage ''X'' of a set ''Y'' by a function ''f'', i.e., ''X'' = ''f'' −1(''Y'' ) = . It can also be viewed as the problem of describing the solution set of ...

Natural sciences

Biology and medicine

Inversion (evolutionary biology) In evolutionary developmental biology, inversion refers to the hypothesis that during the course of animal evolution, the structures along the dorsoventral (DV) axis have taken on an orientation opposite that of the ancestral form. Inversion was ...

, a hypothesis about the evolution of the dorsoventral axis in animals *

Inversion (kinesiology) Motion, the process of movement, is described using specific anatomical terms. Motion includes movement of organs, joints, limbs, and specific sections of the body. The terminology used describes this motion according to its direction relativ ...

, movement of the sole towards the median plane * Chromosomal inversion, where a segment of a chromosome is reversed end-to-end * Inversion therapy, the practice of hanging upside down (heart higher than head) for supposed health benefits

Geology

Inversion (geology) In structural geology inversion or basin inversion relates to the relative uplift of a sedimentary basin or similar structure as a result of crustal shortening. This normally excludes uplift developed in the footwalls of later extensional fa ...

, the relative uplift of a previously basinal area resulting from local shortening, in structural geology * Relief inversion, when a previous depression becomes a landform that stands out from its surroundings * Seismic inversion, transforming seismic reflection data into a quantitative rock-property description of a geological formation

Physics and chemistry

* Island of inversion, a group of elements with abnormal nuclear shell structure *

Nitrogen inversion In chemistry, pyramidal inversion (also umbrella inversion) is a fluxional process in compounds with a pyramidal molecule, such as ammonia (NH3) "turns inside out". It is a rapid oscillation of the atom and substituents, the molecule or ion passi ...

, a chemical process in which a trigonal nitrogen-containing structure turns inside-out *

Population inversion In science, specifically statistical mechanics, a population inversion occurs while a system (such as a group of atoms or molecules) exists in a state in which more members of the system are in higher, excited states than in lower, unexcited energy ...

, in statistical mechanics, when a system exists in state with more members in an excited state than in lower-energy states *

Pyramidal inversion In chemistry, pyramidal inversion (also umbrella inversion) is a fluxional process in compounds with a pyramidal molecule, such as ammonia (NH3) "turns inside out". It is a rapid oscillation of the atom and substituents, the molecule or ion passin ...

, a chemical process in which a trigonal structure turns inside-out *

Inverted sugar syrup Inverted sugar syrup, also called invert syrup, invert sugar, simple syrup, sugar syrup, sugar water, bar syrup, syrup USP, or sucrose inversion, is a syrup mixture of the monosaccharides glucose and fructose, that is made by hydrolytic sacc ...

, a chemical reaction converting sucrose into glucose and fructose

Other uses in the natural sciences

Inverse problem An inverse problem in science is the process of calculating from a set of observations the causal factors that produced them: for example, calculating an image in X-ray computed tomography, source reconstruction in acoustics, or calculating the ...

, the process of calculating from a set of observations the causal factors that produced them * Inversion (meteorology), air temperature increasing with height

Other uses

Priority inversion In computer science, priority inversion is a scenario in scheduling in which a high priority task is indirectly superseded by a lower priority task effectively inverting the assigned priorities of the tasks. This violates the priority model that h ...

, the condition of a low-priority task holding a shared resource that a high-priority task needs * Inversion in postcolonial theory, a discursive strategy/gesture in cultural and subaltern studies *

Roller coaster inversion A roller coaster inversion is a roller coaster element in which the track turns riders upside-down and then returns them to an upright position. Early forms of inversions were circular in nature and date back to 1848 on the Centrifugal railway in ...

, which turns riders upside-down * Tax inversion, a form of tax avoidance by moving corporate ownership to low-tax nations