duality

[doo-al-i-tee, dyoo-]

noun

1. a dual state or quality.

2. Mathematics.,  a symmetry within a mathematical system such that a theorem remains valid if certain objects, relations, or operations are interchanged, as the interchange of points and lines in a plane in projective geometry.

duality

/ djuːˈælɪtɪ /

noun

1. the state or quality of being two or in two parts; dichotomy

2. physics the principle that a wave-particle duality exists in microphysics in which wave theory and corpuscular theory are complementary. The propagation of electromagnetic radiation is analysed using wave theory but its interaction with matter is described in terms of photons. The condition of particles such as electrons, neutrons, and atoms is described in terms of de Broglie waves

3. geometry the interchangeability of the roles of the point and the plane in statements and theorems in projective geometry

Other Word Forms

• nonduality noun

Word History and Origins

Origin of duality¹

1350–1400; Middle English dualitie < Late Latin duālitās. See dual, -ity

Example Sentences

That Seu marries the feminine and the spartan in her space feels intentional — a reflection of the dualities that animate her life and work.

Read more on Los Angeles Times

The original, or "old," duality in physics emerged more than a century ago when scientists realized that light and matter can act as both waves and particles.

Read more on Science Daily

Sir Anthony has always understood the duality of being human, and it explains his acting range.

Read more on BBC

Halloween, for all its associations with extremes of terror, is also bound up in the cozy innocence of childhood memories, and to my mind, few movies fit that duality better than “The Fog.”

Read more on The Wall Street Journal

In “The Bear’s” White, Cooper saw an actor who’d capture Springsteen’s dualities — swagger and fragility, quiet intensity and vulnerability — and who was committed to total immersion.

Read more on Los Angeles Times

Related Words

• artifice 
• chicanery 
• deceit 
• dishonesty 
• falsehood 
• hypocrisy