Since I watched Stargate Continuum </em last week, I’ve been thinking more about the Grandfather Paradox, a puzzle that sooner or later crops up in all good time travel-related science fiction.
The Grandfather Paradox revolves around this question: “What would happen if someone went back in time and killed their own grandfather before the grandfather had a chance to have any children?” By killing their grandfather, the time-traveler erases themselves from existence. But if the time traveler is erased from existence, they couldn’t have travelled back in time to kill their grandfather, so therefore they should exist.
Does the time-traveler exist or not? This is the paradox.
U.S. viewers of Doctor Who are currently being treated to a goosebump-inducing two-parter penned by Steven Moffat, who also wrote the genuinely terrifying “The Empty Child” episode a few seasons back. In his latest offering, Moffat presents us with a library haunted by flesh-eating shadows. The library itself is a wonderful conceit: in the 51st century, e-books and neural downloads and [insert exotic paperless technology here], are all so ho-hum that the people of the future decide to reprint every book ever published on good old fashioned paper. Not surprisingly, it takes an entire planet to store the resulting tomes.
It all sounds completely absurd until you realise that books are currently holding up a lot better than digital technologies when it comes to long-term archiving.