Is time travel real? Can it be? A comprehensive look at the science behind the supposedly science fiction concept of traveling back in time. From Albert Einstein's Special Relativity to General Relativity, String Theory, the Many Worlds or Multiverse Theory, to Cosmic Strings, Black Holes and Wormholes, everything and its potential role in time travel is explained. Do you need a time machine? Can one be made? What energy would that require? Also discussing the many paradoxes of Time Travel including the Grandfather Paradox, as well as Closed Timeline Curves (CTCs) and Causal Loops.