Time travel used to be thought of as just science fiction, but Einstein's general theory of relativity allows for the possibility that we could warp space-time so much that you could go off in a rocket and return before you set out.

Analysis

Einstein's general theory of relativity does allow for solutions (e.g., closed timelike curves) where spacetime is so warped that time travel to the past is theoretically possible, such as in the case of a wormhole or near a rotating black hole (Kerr metric). Hawking himself discussed these possibilities in his work, though he also proposed the 'chronology protection conjecture' suggesting nature might prevent such paradoxes. The statement reflects mainstream theoretical physics interpretations of GR.

Background

General relativity describes gravity as the curvature of spacetime by mass and energy. Solutions like the Gödel metric, Tipler cylinders, and wormholes show that under extreme conditions, time loops could exist. However, these require exotic matter or conditions not yet observed or achievable.

Verdict summary

Hawking accurately summarized Einstein's general relativity as theoretically permitting time travel via spacetime warping.

Sources consulted