What if the dimension of time was no different from the three dimensions of space we live in? What if you could travel to the past and to the future…. the same way you can move right or left, up or down?
Would you be able to change your past? And if you did, would it create a time paradox? What kind of time machine would you need to build, anyway?
What If asks some of the most provocative hypothetical questions in science - and then tries to answer them with the help of established scientific theory and the latest research.