Yesterday And Today

The present and even the future get left behind. Contemporary and even futuristic sf becomes de facto alternative histories, which is why SM Stirling writes them that way in the first place. Sandra Miesel's introductions explicitate that Poul Anderson's Psychotechnic future history series is now an alternative history diverging from the world as we know it in 1958.

Contemporary series become stretched or elongated if their characters remain active in the present while their origins recede further into the past. I disagree with any series that keeps its hero unaging while everything else changes around him. Authors can play tricks with chronology and age but should not just ignore it because it is the most important aspect of life and should therefore be reflected in fiction, however this is done. Over the course of a decade or more, the Matt Helm series stopped referring to Helm's involvement in World War II. The James Bond (book) series changed what it said about Bond's involvement in that war. Bond has two biographies, the first relegated to a fiction within the fiction. Fleming knew how to do it.

Even futuristic series must show change in their characters' lives. Antiagathics or antisenescence will not prevent eventual death by violence or accident or just by living until the end of the universe, as in James Blish's The Triumph of Time. Poul Anderson's Technic History presents complete biographies of David Falkayn and Dominic Flandry and even Nicholas van Rijn, already old at the beginning of his series, becomes older and less active except in emergencies.