I just finished reading the Time Odyssey trilogy that Clarke and Baxter wrote. Not bad, although I suspect it was mostly Baxter's writing. Clark was inspirational when I was a youth, because his sciece fiction was hard-core, and I enjoyed his non-fiction "Promise of Space". A first edition hardcover of that book is on my shelf here.
I also enjoyed Asimov's non-fiction books on science and chemistry. And there were amazing documentaries about science back then, like
The Ascent of Man, possibly the best TV series ever made.
I wonder what is inspiring young people today to learn science? I was infuriated by
The Universe, which failed to teach anything. It interviewed nobodies like some guy who works for
www.science.com. The chapter on Venus didn't mention a single spacecraft to visit the planet, and they kept interviewing some guy who works at a museum (David Grinspoon) who said something incorrect everytime he spoke. Total rubbish!