Superb book on the current theory of physics, explaining not only String theory under M theory, but how we could view time and space, and the possibility to time travel.
Good read for those who are curious about the universe we live in, and how human living on this very small planet is doing in trying to understanding the very large universe we live in.
The expansion of universe, especially the spending up of it, lead us to appreciate the stars that we could still see visually now. In 100 billion, the stars are moving too far away for the most powerful telescopes.
The mathematical part of it might put off a few readers. Just skip through that and read the concepts backing up by the maths and you will live it much more.
I found out that there are four parts video by Brian Greene that talked about the topics raised in the book. Even better.