"In some timelines, it happens. It didn't in mine. We had two more world wars instead. Not quite the 'post-apocalyptic nuclear holocaust' scenario, but it came really close." He gives a studying look to the trash as the pass it, as if analyzing the strangeness of littering - everything is recycled where he's from.

"The future is a mix of probability and choice. A lot of things are possible. Whether they happen? That depends on people."

He nods at the mention of reading lots of books. "It's the easiest and least conspicuous way to record them. Arcadia - one of the biggest cities on Earth at home - is putting together a huge digital library, and it's really a help to bring back any books that might have been lost during the rougher parts of history."