# Inversion

Inversion or inversions may refer to:

## Arts

* Inversion (artwork), a 2005 temporary sculpture in Houston, Texas
* Inversion (music), 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), 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, a figure of speech also known as an inversion

## Mathematics and logic

* Additive inverse
* Involution (mathematics), a function that is its own inverse (when applied twice, the starting value is obtained)
* Inversion (discrete mathematics), any item that is out of order in a sequence
* Inverse element
* Inverse function, a function that undoes the operation of another function.
* Inversive geometry#Circle inversion, a transformation of the Euclidean plane that maps generalized circles to generalized circles
* Inversion in a point, or point reflection, a kind of isometric (distance-preserving) transformation in a Euclidean space
* Inversion transformation, 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, the reciprocal of a number (or any other type of element for which a multiplication function is defined)
* Matrix inversion, an operation on a matrix that results in its multiplicative inverse
* Model inversion
* Set inversion

## Natural sciences
### Biology and medicine

* Inversion (evolutionary biology), a hypothesis about the evolution of the dorsoventral axis in animals
* Inversion (kinesiology), 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), the relative uplift of a previously basinal area resulting from local shortening, in structural geology
* Quartz inversion, a change in the crystal structure of quartz at high temperatures
* 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, a chemical process in which a trigonal nitrogen-containing structure turns inside-out
* Population inversion, in statistical mechanics, when a system exists in state with more members in an excited state than in lower-energy states
* Pyramidal inversion, a chemical process in which a trigonal structure turns inside-out
* Inverted sugar syrup, a chemical reaction converting sucrose into glucose and fructose

### Other uses in the natural sciences

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