If you were to travel back in time to yesterday, the Earth would be in a different place in space. Even if you travel back in time one second, the Earth below your feet can move nearly half a kilometer. In one second. The reason every movie about time travel is nonsense is that the Earth moves, constantly, always. You travel back one day, you don’t end up in the same location—you end up in the gaping vacuum of outer space. Marty McFly didn’t appear thirty years earlier in his hometown of Hill Valley, California. His tricked-out DeLorean materialized in the endless empty blackness of the cosmos
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