What is "arrow of time"

alt. 1 A term used to distinguish a direction of time within a four-dimensional relativistic view of the cosmos. 2 The subjective feeling of movement from past to future. 3 entropy. n. 1 A term used to distinguish a direction of time within a four-dimensional relativistic view of the cosmos. 2 The subjective feeling of movement from past to future. 3 entropy.

The Arrow of Time, or Time's Arrow, is a concept developed in 1927 by the British astronomer Arthur Eddington involving the "one-way direction" or "asymmetry" of time. This direction, according to Eddington, can be determined by studying the organization of atoms, molecules, and bodies, might be drawn upon a four-dimensional relativistic map of the world ("a solid block of paper").

Physical processes at the microscopic level are believed to be either entirely or mostly time-symmetric: if the direction of time were to reverse, the theoretical statements that describe them would remain true. Yet at the macroscopic level it often appears that this is not the case: there is an obvious direction (or flow) of time.

"Arrow of Time" is the 11th episode of the fifth season of the American television show Numb3rs. In the episode, Federal Bureau of Investigation (FBI) agents track an escaped prisoner who is seeking revenge against one of their own. Written by series writer/executive producer Ken Sanzel, the episode continued two storylines. The first storyline continued one that began with two episodes shown very early in season three. The other was originally launched in the season four season finale " When Worlds Collide".

"Arrow of Time" first aired in the United States on January 9, 2009.

The arrow of time is a concept concerning the "one-way direction" or "asymmetry" of time.

Arrow of time may also refer to:

• "Arrow of Time" (Numbers), an episode of Numb3rs
• Arrow of Time/The Cycle of Time, an album by Kuckuck Schallplatten