Time


 * For the entity of the same name, see Time (Eternal).

Time is the dimension through which space-time vessels travel. The Web of Time governs order within this realm.

Explanations of time
Time was one of the five dimensions described by Susan Foreman and from which she derived the name TARDIS, which she came up with herself. (DW: An Unearthly Child) While Susan described time as a dimension, the Master (in the guise of "Professor Thascalos") described time as made up of particles, known as chronons. (DW: The Time Monster) The Doctor later laboured in an effort to explain how time is misunderstood and never strictly linear, that it is made up of "timey-wimey... stuff." (DW: Blink)

A certain moment in time can be fixed, where something must happen, like the volcanic eruption of Mount Vesuvius at Pompeii. It can also be in flux, allowing minor changes to history. Also, events in Earth's history can't change the present, like the CyberKing rising from the Thames in Victorian London. Time isn't in a straight line but is more of a four-dimensional 'circle', and the location where TARDISes travel is the unexplained Time Vortex, which is also used to travel through space as well as time.

Space-Time has never been fully explained, but a connection to it on Gallifrey, the Untempered Schism, had been previously formed; the Schism is famous for inspiring the Doctor to travel through space-time, and driving the Master insane. (DW: The Sound of Drums)