After alien invasions and Samuel L. Jackson appearances, time travel is the next best plot device Hollywood can inject into a film to maximize audience attendance.
The latest example: Men In Black 3 (released next week -- in 3D!), in which Will Smith goes back to the 1960's to meet a younger version of Tommy Lee Jones' Agent K (this time played by Josh Brolin). Hilarity and a catchy, non-offensive rap tune will no doubt ensue.
Later this summer, Joseph Gordon Levitt and Bruce Willis will appear together in Looper about an assassin sent back in time to off himself. As a fan of the genre, I'll no doubt see both of these movies -- only to be disappointed as soon as the theater lights go up.
The esteemed Dr. Emmett Brown once said that time travel was too dangerous to be used - whether for fear of ripping the space time continuum or simply angering obsessive dorks over plot inconsistencies.
These kinds of stories are hard to pull off, but with each passing blockbuster, time travel rules become blurred and logic falls to the wayside in favor of a convenient deus ex machina.
The devil is always in the details, so the following serves as a deconstruction of some of the most popular, but greatest offenders in the time travel genre.
3. Back To the Future
The first Back to the Future film operates off of the notion of a "Grandfather Paradox," in which a time traveler who goes back in time and kills his grandfather cannot be born and therefore cannot go back in time in the first place. However, this logic completely falls apart as the movie goes on.
The film posits that if Marty McFly's would-be parents do not kiss at the Enchantment Under the Sea Dance, Marty and his siblings will never be born. However, if Marty never existed, how did he go back in time to disrupt his parents' first meeting?
Without Marty's interference in 1955, George McFly and Lorraine Baines would meet normally, eventually be married and have children, one of which would take up with an eccentric physicist and travel back in time in a nuclear powered DeLorean.