Bipolar may refer to:

Astronomy

Bipolar nebula A bipolar nebula is a type of nebula characterized by two lobes either side of a central star. About 10-20% of planetary nebulae are bipolar. Formation Though the exact causes of this nebular structure are not known, it is often thought to impl ...

, a distinctive nebular formation *

Bipolar outflow A bipolar outflow comprises two continuous flows of gas from the poles of a star. Bipolar outflows may be associated with protostars (young, forming stars), or with evolved post-AGB stars (often in the form of bipolar nebulae). Protostars In t ...

, two continuous flows of gas from the poles of a star

Mathematics

Bipolar coordinates Bipolar coordinates are a two-dimensional orthogonal coordinate system based on the Apollonian circles.Eric W. Weisstein, Concise Encyclopedia of Mathematics CD-ROM, ''Bipolar Coordinates'', CD-ROM edition 1.0, May 20, 1999 Confusingly, the sam ...

, a two-dimensional orthogonal coordinate system * Bipolar set, a derivative of a

polar set In functional and convex analysis, and related disciplines of mathematics, the polar set A^ is a special convex set associated to any subset A of a vector space X lying in the dual space X^. The bipolar of a subset is the polar of A^, but lies ...

Bipolar theorem In mathematics, the bipolar theorem is a theorem in functional analysis that characterizes the bipolar (that is, the Polar set, polar of the polar) of a set. In convex analysis, the bipolar theorem refers to a necessary and sufficient conditions f ...

, a theorem in convex analysis which provides necessary and sufficient conditions for a cone to be equal to its bipolar

Medicine

Bipolar disorder Bipolar disorder, previously known as manic depression, is a mental disorder characterized by periods of depression and periods of abnormally elevated mood that last from days to weeks each. If the elevated mood is severe or associated with ...

, a mental disorder that causes periods of depression and periods of elevated mood ** Bipolar I disorder, a bipolar spectrum disorder characterized by the occurrence of at least one manic or mixed episode **

Bipolar II disorder Bipolar II disorder (BP-II) is a mood disorder on the bipolar spectrum, characterized by at least one episode of hypomania and at least one episode of major depression. Diagnosis for BP-II requires that the individual must never have experien ...

, a bipolar spectrum disorder characterized by at least one episode of hypomania and at least one episode of major depression **

Bipolar disorder not otherwise specified Bipolar disorder not otherwise specified (BD-NOS) is a diagnosis for bipolar disorder (BD) when it does not fall within the other established sub-types. Bipolar disorder NOS is sometimes referred to as subthreshold bipolar disorder. Classificati ...

, a diagnosis for bipolar disorder when it does not fall within the other established sub-types *

Bipolar neuron A bipolar neuron, or bipolar cell, is a type of neuron that has two extensions (one axon and one dendrite). Many bipolar cells are specialized sensory neurons for the transmission of sense. As such, they are part of the sensory pathways for smell ...

, a type of neuron which has two extensions

Music

* ''Bipolar'' (Up Dharma Down album), 2008 * ''Bi-Polar'' (Vanilla Ice album), 2001 * ''Bipolar'', a 2009 album by rock group El Cuarteto de Nos *"Bipolar", a song by Blonde Redhead from their 1997 album '' Fake Can Be Just as Good'' * "Bipolar", a song by Gloria Trevi from her 2013 album ''De Película'' * "Bipolar", a song by Gucci Mane from his 2018 album '' Evil Genius'' *"Bipolar", a 2019 song by

Kiiara Kiara Saulters (born May 24, 1995), known professionally as Kiiara, is an American singer and songwriter from Wilmington, Illinois. She is currently signed to Atlantic Records. Her 2015 single "Gold" peaked at number 13 on the ''Billboard'' H ...

*"Bi Polar", a 2021 song by

Bhad Bhabie Danielle Bregoli (born March 26, 2003), known professionally as Bhad Bhabie (, "bad baby"), is an American rapper and internet personality. She first became known from an appearance on ''Dr. Phil'' in September 2016, in which she uttered the phr ...

Technology

Bipolar electricity transmission A high-voltage direct current (HVDC) electric power transmission system (also called a power superhighway or an electrical superhighway) uses direct current (DC) for electric power transmission, in contrast with the more common alternating curre ...

, using a pair of conductors in opposite polarity *

Bipolar encoding In telecommunication, bipolar encoding is a type of return-to-zero (RZ) line code, where two nonzero values are used, so that the three values are +, −, and zero. Such a signal is called a duobinary signal. Standard bipolar encodings are designed ...

, a type of line code where two nonzero values are used **

Bipolar violation A bipolar violation, bipolarity violation, or BPV, is a violation of the bipolar encoding rules where two pulses of the same polarity occur without an intervening pulse of the opposite polarity. This indicates an error in the transmission of the ...

, a violation of the bipolar encoding rules * Bipolar electric motor, an electric motor with only two poles to its stationary field **

Bipolar (locomotive) The Milwaukee Road's class EP-2 comprised five electric locomotives built by General Electric in 1919. They were often known as Bipolars, which referred to the bipolar electric motors they used. Among the most distinctive and powerful electric ...

, a locomotive using a bipolar electric motor *

Bipolar signal In telecommunication, a bipolar signal is a signal that may assume either of two polarities, neither of which is zero. A bipolar signal may have a two-state non-return-to-zero (NRZ) or a three-state return-to-zero (RZ) binary coding A binary ...

, a signal that may assume either of two polarities, neither of which is zero

Transistors

Bipolar junction transistor A bipolar junction transistor (BJT) is a type of transistor that uses both electrons and electron holes as charge carriers. In contrast, a unipolar transistor, such as a field-effect transistor, uses only one kind of charge carrier. A bipola ...

(BJT) *

Heterojunction bipolar transistor The heterojunction bipolar transistor (HBT) is a type of bipolar junction transistor (BJT) which uses differing semiconductor materials for the emitter and base regions, creating a heterojunction. The HBT improves on the BJT in that it can handle s ...

(HBT) *

Insulated-gate bipolar transistor An insulated-gate bipolar transistor (IGBT) is a three-terminal power semiconductor device primarily used as an electronic switch, which, as it was developed, came to combine high efficiency and fast switching. It consists of four alternating lay ...

(IGBT)

Other uses

* Bipolarity,

polarity in international relations Polarity in international relations is any of the various ways in which power is distributed within the international system. It describes the nature of the international system at any given period of time. One generally distinguishes three types o ...

involving two states