Torsion may refer to:

Science

* Torsion (mechanics), the twisting of an object due to an applied torque * Torsion of spacetime, the field used in Einstein–Cartan theory and ** Alternatives to general relativity *

Torsion angle A dihedral angle is the angle between two intersecting planes or half-planes. In chemistry, it is the clockwise angle between half-planes through two sets of three atoms, having two atoms in common. In solid geometry, it is defined as the uni ...

, in chemistry

Biology and medicine

Torsion fracture A spiral fracture (a.k.a. torsion fracture) is a bone fracture occurring when torque (a rotating force) is applied along the axis of a bone. Spiral fractures often occur when the body is in motion while one extremity is planted. For example, a spi ...

or spiral fracture, a bone fracture when torque is applied * Organ torsion, twisting that interrupts the blood supply to that organ: ** Splenic torsion, causing

splenic infarction Splenic infarction is a condition in which blood flow supply to the spleen is compromised, leading to partial or complete infarction (tissue death due to oxygen shortage) in the organ. Splenic infarction occurs when the splenic artery or one of i ...

** Ovarian torsion ** Testicular torsion *

Penile torsion Penile torsion is a fairly common congenital condition with male infants. It occurs up to about 1 in 80 newborn males. With this condition, the penis appears rotated on its axis, almost always to the left (counterclockwise). See also * Chordee ...

, a congenital condition * Torsion of the digestive tract in some domestic animals: ** Torsion, a type of

horse colic Colic in horses is defined as abdominal pain, but it is a clinical symptom rather than a diagnosis. The term colic can encompass all forms of gastrointestinal conditions which cause pain as well as other causes of abdominal pain not involving the g ...

Gastric torsion Gastric dilatation volvulus (GDV), also known as gastric dilation, twisted stomach, or gastric torsion, is a medical condition that affects dogs in which the stomach becomes overstretched and rotated by excessive gas content. The word bloat is o ...

, or gastric dilatation volvulus * Torsion (gastropod), a developmental feature of all gastropods

Mathematics

* Torsion of a curve * Torsion tensor, in differential geometry * Torsion (algebra), in ring theory * Torsion group, in group theory and arithmetic geometry * Tor functor, the derived functors of the tensor product of modules over a ring * Torsion-free module, in algebra *

Analytic torsion In mathematics, Reidemeister torsion (or R-torsion, or Reidemeister–Franz torsion) is a topological invariant of manifolds introduced by Kurt Reidemeister for 3-manifolds and generalized to higher dimensions by and . Analytic torsion (or Ray– ...

(Reidemeister torsion, R-torsion, Franz torsion, de Rham torsion, Ray-Singer torsion), a topological invariant of manifolds *

Whitehead torsion In geometric topology, a field within mathematics, the obstruction to a homotopy equivalence f\colon X \to Y of finite CW-complexes being a simple homotopy equivalence is its Whitehead torsion \tau(f) which is an element in the Whitehead group \ope ...

, in geometric topology

Other uses

Torsion field (pseudoscience) A torsion field (also called axion field, spin field, spinor field, and microlepton field) is a feature of pseudoscientific proposals that the quantum spin of particles can be used to cause emanations to carry information through vacuum orders of ...

, a field alleged to make faster-than-light communication and paranormal phenomena possible {{disambiguation, maths