Quanta

Part of speech: noun

Definitions

1. A specific, discrete quantity of energy or matter, as in quantum physics
2. The minimal amount of any physical entity involved in an interaction, often representing a packet of energy
3. Units that characterize the fundamental properties of particles and waves, essential in quantum mechanics

Etymology: "Quanta" is the plural of "quantum," a Latin noun meaning "how much" or "how great," built from the interrogative stem "quantus" ("how much"). The English plural "quanta" keeps the Latin ending, so physicists speak of many quanta, while everyday speakers sometimes treat "quantum" itself as a plural and say "a quantum" for a single unit. The jump from a simple Latin question to a precise physical idea happened in 1900, when Max Planck proposed that energy is emitted and absorbed in discrete packets rather than in a continuous flow. Planck used the term to describe these fixed minimal portions, and the word has kept that sense of an indivisible step ever since. A quantum in this sense is the smallest unit a physical quantity can change by, which is why the word now also appears in phrases like "quantum leap" for an abrupt, step-like change.

Synonyms: quantities, amounts, units, measurements, elements