<P> The lead character of the series is Marty McFly . During the course of the trilogy, he travels through time using a DeLorean time machine invented by his friend Emmett Brown and encounters the villain, Biff Tannen, in several different time periods and visits his family ancestors and descendants . </P> <P> Martin Seamus "Marty" McFly (portrayed by Michael J. Fox in the films and voiced by David Kaufman in the animated series and AJ LoCascio in Back to the Future: The Game) is the son of George McFly and Lorraine Baines McFly . Marty travels between the past and the future, encountering his ancestors and descendants . Marty and his friend Doc Brown help restore the space - time continuum while encountering Biff Tannen (or members of the Tannen clan) at various points in time . </P> <P> Doctor Emmett Lathrop "Doc" Brown (portrayed by Christopher Lloyd in the films and Back to the Future: The Game, and voiced by Dan Castellaneta in the animated series) is the inventor of the DeLorean time machine . At various points in time, Doc helps Marty restore the space - time continuum and reverse the changes that were caused by time travel . </P> <P> In 2008, the character was selected by film magazine Empire as one of The 100 Greatest Movie Characters of All Time, ranking at #20 . </P>

Name of the scientist in back to the future