Time is also of significant social importance, having economic value (' time is money') as well as personal value, due to an awareness of the limited time in each day and in human life spans.ĭefining time in a manner applicable to all fields without circularity has consistently eluded scholars. Temporal measurement has occupied scientists and technologists and has been a prime motivation in navigation and astronomy. Throughout history, time has been an important subject of study in religion, philosophy, and science. Through advances in both theoretical and experimental investigations of spacetime, it has been shown that time can be distorted and dilated, particularly at the edges of black holes. General relativity is the primary framework for understanding how spacetime works. The SI base unit of time is the second, which is defined by measuring the electronic transition frequency of caesium atoms. Time is one of the seven fundamental physical quantities in both the International System of Units (SI) and International System of Quantities.

Time is often referred to as a fourth dimension, along with three spatial dimensions. It is a component quantity of various measurements used to sequence events, to compare the duration of events or the intervals between them, and to quantify rates of change of quantities in material reality or in the conscious experience. Time is the continued sequence of existence and events that occurs in an apparently irreversible succession from the past, through the present, into the future.

History of horology poster