Children of Time delves into the hard scifi genre almost immediately. For example,

There were no windows in the Brin 2 facility - rotation meant that ‘outside’ was always ‘down’, underfoot, out of mind. The wall screens told a pleasant fiction, a composite view of the world below that ignored their constant spin, showing the planet as hanging stationary-still off in space: the green marble to match the blue marble of home, twenty light years away.

The sentences seem a bit too long to read. But the content has some interesting science-rooted ideas. Another one, for example, is:

Alongside the Barrel was the Flask: the delivery system for the virus that would accelerate the monkeys along their way - they would stride, in a mere century or two, across physical and mental distances that had taken humanity millions of long and hostile years