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Space Time
Doc Brown: I foresee two possibilities. One: coming face-to-face with herself thirty years older would put her into shock and she'd simply pass out. Or two: the encounter could create a time paradox, the result of which could cause a chain reaction that would unravel the very fabric of the spacetime continuum and destroy the entire universe! Granted, that's a worst-case scenario. The destruction might in fact be very localised, limited to merely our own galaxy.
Marty McFly: Well, that's a relief.
Back to the Future Part II (1989), written by Robert Zemeckis and Bob Gale.
Space Time. Artist concept of Gravity Probe B orbiting the Earth to measure space-time, a four-dimensional description of the universe including height, width, length, and time.
