Time

Time is the continued sequence of existence and events that occurs in an apparently irreversible succession from the past, through the present, and into the future.[1][2][3] 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.[4][5][6][7] Time is often referred to as a fourth dimension, along with three spatial dimensions.[8][9]

Time is one of the seven fundamental physical quantities in both the International System of Units (SI) and International System of Quantities. The SI base unit of time is the second, which is defined by measuring the electronic transition frequency of caesium atoms. General relativity is the primary framework for understanding how spacetime works.[10] 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.

Throughout history, time has been an important subject of study in religion, philosophy, and science. Temporal measurement has occupied scientists and technologists and has been a prime motivation in navigation and astronomy. 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.

  1. ^ "Oxford Dictionaries:Time". Oxford University Press. 2011. Archived from the original on 4 July 2012. Retrieved 18 May 2017. The indefinite continued progress of existence and events in the past, present, and future regarded as a whole
  2. ^ Cite error: The named reference DefRefs02 was invoked but never defined (see the help page).
  3. ^ "Time". The American Heritage Dictionary of the English Language (Fourth ed.). 2011. Archived from the original on 19 July 2012. A nonspatial continuum in which events occur in apparently irreversible succession from the past through the present to the future.
  4. ^ Merriam-Webster Dictionary Archived 8 May 2012 at the Wayback Machine the measured or measurable period during which an action, process, or condition exists or continues : duration; a nonspatial continuum which is measured in terms of events that succeed one another from past through present to future
  5. ^ Compact Oxford English Dictionary A limited stretch or space of continued existence, as the interval between two successive events or acts, or the period through which an action, condition, or state continues. (1971).
  6. ^ Cite error: The named reference DefRefs01 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Poidevin was invoked but never defined (see the help page).
  8. ^ "Newton did for time what the Greek geometers did for space, idealized it into an exactly measurable dimension." About Time: Einstein's Unfinished Revolution, Paul Davies, p. 31, Simon & Schuster, 1996, ISBN 978-0-684-81822-1
  9. ^ Bunyadzade, Konul (15 March 2018). "Thoughts of Time" (PDF). Metafizika Journal (in Azerbaijani). 1. AcademyGate Publishing: 8–29. doi:10.33864/MTFZK.2019.0. Archived (PDF) from the original on 5 April 2019. Retrieved 15 March 2018.
  10. ^ Rendall, Alan D. (2008). Partial Differential Equations in General Relativity (illustrated ed.). OUP Oxford. p. 9. ISBN 978-0-19-921540-9. Archived from the original on 14 April 2021. Retrieved 24 November 2020.