Complex sentence: As for nanobots Linden believes the spaces available in the brain for motion are simply too small, so he feels someday we will understand the brain fully, but not on Kurzweil's timetable.
Split into simpler sentences: As for nanobots Linden believes the spaces available in the brain for navigation are simply too small. He believes someday we will fully understand the brain, but not on Kurzweil's timetable.