[7] Max Tegmark has argued that, if there is more than one time dimension, then the behavior of physical systems could not be predicted reliably from knowledge of the relevant partial differential equations.
Dunne suggested that, in the context of a "block" spacetime as modelled by General Relativity, a second dimension of time was needed in order to measure the speed of one's progress along one's own timeline.
[10] He published his theory in relation to precognitive dreams in his 1927 book An Experiment with Time and went on to explore its relevance to contemporary physics in The Serial Universe (1934).
[15] Fantasy writers such as J. R. R. Tolkien and C. S. Lewis have made use of these and other multiple time dimensions, such as those proposed by Dunne, in some of their most well-known stories.
[16] Science fiction author H. Beam Piper, in his Paratime series of short stories and novel that multiple timelines exist as "worlds of alternate probability on the lateral dimension of time.
"[17] In Dragon Ball Z, hyperbolic time chambers - in which one year inside is equal to one day outside - are used to accelerate martial arts training.