The theory was that our earth and their earth parted at the burning of the Library of Alexandria. At least that’s what the philosophers and scientists suggest. They also postulate that if we have one parallel universe, we can have a myriad. There could be earths where the dinosaurs were never wiped out; there could be earths where mankind never got going; there could be earths where mankind had already become extinct; there could even be earths where putting milk in your tea first was acceptable.
