The last few weeks have seen a flurry of 'Back to the Future' nostalgia, as the celebration of the official arrival of Marty's future caused everyone to go back and rewatch the original movies and incessantly blog about them. (Those people blogging about 'Back to the Future' should be ashamed of themselves.)
While rewatching the movie with my family, we got into a conversation about Marty's dangerous tampering with future history--not the stuff with his family or Mayor Goldie Wilson or Biff. No, Marty dropped "Darth Vader" into conversation with a science fiction fan who goes on to be a published author, decades before 'Star Wars' even happened. (He also mentions the planet Vulcan, but that's a much less serious risk because Star Trek's Vulcan was named after the hypothetical planet astronomers once believed to exist inside the orbit of Mercury. It was actually used in several other science fiction stories that predate Trek.)
So, the question we had was, "Did Marty's slip of the tongue create a parallel timeline where Darth Vader wasn't the villain of the Star Wars movies?" We came up with three possibilities.
1) No. Marty's dad forgot the name and came up with something else for his radiation-suited matchmaker in his book, 'A Match Made in Space'. History stays on its track.
2) No. Marty's dad made his money (he doesn't appear to have the same office job he did in the original timeline) not through writing, but through creative lawyering; he published the short story that would later be used as the basis for 'A Match Made in Space' back in the late 50s/early 60s, and when 'Star Wars' came out, George McFly sued George Lucas for plagiarism. They settled out of court for an undisclosed sum that allowed McFly to live in comfort and write in leisure.
3) No. (This one is my favorite.) Instead, in this timeline, George McFly went on to write for television and film (remember, they only said it was his first novel) and worked with luminaries of science fiction like Gene Roddenberry and George Lucas. In the revised timeline, he actually suggested the names "Vulcan" and "Darth Vader". Basically, Marty McFly rewrote history so that his dad created both Star Wars and Star Trek.
Which means that JJ Abrams is, I suppose, his spiritual heir...