In Brian Greene's "The Fabric of the Cosmos: Illusion of Time" on PBS, http://www.pbs.org/wgbh/nova/physics/fabric-of-cosmos.html#fabric-time", he explains that if an alien were 10 billion light years away but not moving, the alien's current time (his "now slice") would be in sync with someone here on earth. However, if the alien then started moving away from Earth (even at a slow speed) , his "now slice" would be angled, resulting in his future becoming "in sync" with Earth's distant past. Even more strange, if he were to move towards Earth instead of away from it, his "now slice" would be angled towards the future so that his future would be in sync with Earth's distant future. Very Confusing! Is this implying that Earth's future is already written? And how does the alien moving towards us make his "now slice" become in sync with our distant future?
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