The idea of time travel is both exciting and dangerous, if it was possible who could stop rogue time travellers going back in time to change history to suit their own agenda? This is a worry and maybe why time travel is a secret science, there are bound to be researchers working on this funded by governments and business. Maybe that is a dream and time travel is just a great topic for science fiction movies, TV shows and books. Yet, if time travel is possible, what would it be like? Well as usual there are ideas about that too and this graphic found on the Daily Pic Dump explains the three theories on time travel. You must make your own mind up about these ideas and then decide for yourself if time travel is possible, happening or just a theory!