Eccentricity
# Eccentricity

Eccentricity or eccentric may refer to:

## Mathematics, science and technology

### Mathematics

* Off-center, in geometry
* Eccentricity (graph theory) of a vertex in a graph
* Eccentricity (mathematics), a parameter associated with every conic section

### Orbital mechanics

* Orbital eccentricity, in astrodynamics, a measure of the non-circularity of an orbit
* Eccentric anomaly, the angle between the direction of periapsis and the current position of an object on its orbit
* Eccentricity vector, in celestial mechanics, a dimensionless vector with direction pointing from apoapsis to periapsis
* Eccentric, a type of deferent, a circle or sphere used in obsolete epicyclical systems to carry a planet around the Earth or Sun

### Other uses in science and technology

* Eccentric (mechanism), a wheel that rotates on an axle that is displaced from the focus of the circle described by the wheel
* Horizontal eccentricity, in vision, degrees of visual angle from the center of the eye
* Eccentric contraction, the lengthening of muscle fibers
* Eccentric position of a surveying tripod, to be able to measure hidden points
* Eccentric training, the motion of an active muscle while it is lengthening under load
* Eccentricity, a deviation from concentricity

## Other uses

* Eccentric Club, a London gentlemen's club
* The Eccentric
* The Eccentrics
