You can’t change the past – sad, but true, at least with today’s technology (and if they were going to invent past-changing technology in the future, wouldn’t they have changed their past with it so that we’d already have it by now?).In the world of fiction, though, there’s no problem with rewriting the history of a beloved character or universe. This act – of telling stories that change the established past of a fictional entity – is known as retconning. It’s short for retroactive continuity. It can be done subtly (by just quietly filling in details that make no sense in light of the original, like the Star Wars prequels) or blatantly (as with the new Star Trek – but no spoilers from us) or just plain weirdly (as in Dallas, where an entire season was revealed to be a dream).
The term, as so many other useful and confusing things do, comes from comics books, where Superman, Batman and their friends have had their pasts redone dozens of times apiece – and every decade or so things get so confusing that their whole universe just starts again, only to swiftly become just as confusing as before.
