This story is part of BBC Earth's "Best of 2016" list, our greatest hits of the year. Browse the full list.
In theory this is not the only Universe that might exist, and in many others, identical copies of us can be found.
The question is, how do we get there?
BBC Earth's Melissa Hogenboom goes on the hunt for her cosmic twin.
Melissa Hogenboom is BBC Earth's feature writer. She is @melissasuzanneh on Twitter. Video produced by Pierangelo Pirak, he is @ppirak on twitter.
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