Across Realtime by Vernor Vinge
This is two books on the inside-- the first, The Peace War, was a reread, though it has been a while. I liked it still-- it's an interesting world, the Peace Authority makes sense [though I'm really curious about those first weeks dismantling the old world], and the path to the book's present is fascinating. The devastated low population world is quirky and unique. The struggle and Paul's legendary skills seem a bit much at times, but it all works out well.
The second book, Across Realtime, expands on the bobble concept and seizes on it as a method of passing into the future-- just bobble ahead and see what the world's like when you get there. But everything is gone when the novel starts-- some time after 2209 the human race disappears, and everyone coming out of their bobbles finds a wasteland. The book develops into an interesting hop across time, a big murder mystery with advanced technology, and a war between leftover fanatics. While the "low techs" are mostly undifferentiated, the high techs are all interestingly developed.