Kvaternární

Kvaternární is a Czech adjective meaning related to quaternary, a term used across different scientific fields to denote things associated with the number four or with fourfold structure. The meaning depends on context and discipline.

In geology and paleontology, kvaternární refers to the Quaternary, the most recent major interval of the Earth's geologic time scale, spanning roughly from 2.58 million years ago to the present. The Quaternary includes the Pleistocene and Holocene epochs and is characterized by repeated glacial and interglacial cycles, climatic fluctuations, and the development and dispersal of Homo sapiens. It marks the period of significant environmental change and the rise of human civilizations.

In mathematics and related disciplines, kvaternární relates to quaternions, a four-dimensional number system that extends complex numbers. A quaternion consists of a real part and three imaginary parts and is governed by non-commutative multiplication. Quaternions are commonly written in the form a + bi + cj + dk, with the fundamental relations i^2 = j^2 = k^2 = ijk = -1. Introduced by William Rowan Hamilton in the 1840s, they are widely used to represent and compute rotations in three-dimensional space, notably in computer graphics, robotics, aviation, and physics, due to their efficiency and numerical stability compared to other rotation representations.

Etymology: the term derives from Latin quaternarius meaning “of four.” The Czech adjective kvaternární is formed analogously to describe entities associated with these fourfold structures or with quaternions.