Elementary Temporal Mechanics

Elementary Temporal Mechanics was a course taught at Starfleet Academy during the mid-24th century that dealt with the basics of time travel.

When the crew of the USS Defiant (2370) traveled back in time to 2268, Doctor Julian Bashir was worried that a flirtatious Lieutenant Watley was his great-grandmother, and that he may be facing a predestination paradox – which he learned about in Elementary Temporal Mechanics – where he was destined to become his own great-grandfather.