Felt I had to post a review because a) I just finished it and b) Mr Bielby used the word "fun" in his. I don't think that really applies. Tau Zero's pretty bleak at times. But it's also very beautiful.
PhysNatScis will like this best, because it's basically a novel-length explanation of special relativity (with a bit of general thrown in for good measure, along with some speculative cosmology). I've no idea how readable it would be to someone who hasn't done 1A physics but I suspect Anderson's a good enough science communicator to make it understandable.
What really rang true for me was the sense of scale. Anderson's descriptions of the view from the spaceship window are breathtaking. His characters are credible and his plot is capable, but it's his prose that really excels. This'll be an Interstellar-scale movie in a few years, mark my words.