There is a star, many light years away. If you exist in two locations at once simultaneously, from which the star is visible, and those two locations are not the same distance from the star, then intuitively, by seeing the star first from the closer position, you can know what it will look like from the second before it happens.
Less trivially, by altering the relative speeds of the two versions (with FTL telepathy), and setting up suitable devices for signaling, I think in theory, this would enable turning FTL into time travel. (Person A performs a calculation, and sends the results to Person B. Since Person A is the future version of person B, and they’re the same person in two places at once simultaneously, then by ‘de-synchronizing them right’ a message can be sent into the past.)
There is a star, many light years away. If you exist in two locations at once simultaneously, from which the star is visible, and those two locations are not the same distance from the star, then intuitively, by seeing the star first from the closer position, you can know what it will look like from the second before it happens.
Less trivially, by altering the relative speeds of the two versions (with FTL telepathy), and setting up suitable devices for signaling, I think in theory, this would enable turning FTL into time travel. (Person A performs a calculation, and sends the results to Person B. Since Person A is the future version of person B, and they’re the same person in two places at once simultaneously, then by ‘de-synchronizing them right’ a message can be sent into the past.)