Storyline: 3/5 
 Characters: 2/5 
 Writing Style: 2/5 
 World: 4/5 
 I call myself a science fiction enthusiast, but I'm really a sucker for space exploration stories. Robot technology? - meh, okay. Time travel? - I'll pass. Alternative universes? - not really my thing. Cybernetics, biomedical engineering, space battles, intergalactic politics? Avoid when possible, acceptable, sure, fine. But give me a story where we're voyaging to a distant planet, and I'm all delight. Tau Zero, then, was written for people like me. I enjoyed it, but it is one of those books where I could agree with someone else who really didn't like it. You have to take some pleasure in (or at least patiently endure) a lot of hard scientific explanation, and you have to find satisfaction in role-playing. So much of the reading experience of these type of novels depends on you being able to visualize yourself as one of the characters or aboard for the adventure; you've got to think of how you would react and what you would do. If you read along just to watch what unfolds and to see where it all ends, then this is going to disappoint. 
 This would make for a good movie. It would have to be one of those lower-budget, stylish, independent-leaning films like Moon or Sunshine (or a higher budget, mainstream one like Gattaca or Mr. Nobody). Heavy on the musical score, lots of awkward, extended silences and camera close-ups. Poul Anderson missed the opportunity to convincingly convey the mood of our adventurers. The intent and perhaps even the effort was there, but I'd like to see someone else take a try at this and see if they can pull out inner feelings and public tensions in and among the crew members. 
 The speculative fiction component of this was a lot of fun. The "What if...?" element was provocative and the hard science complemented it. I was troubled a little because I had read something similar but that had actually been written later (view spoiler)[ Haldeman's Forever War (hide spoiler)]. Thus I had attributed creativity to the wrong author. So now I hold that later book in lower regard. It also makes me realize that this is probably a time-dependent novel. Even if it were the first of its kind to take on this theme, it has been duplicated and emulated so many times since, that readers of more contemporary science fiction (myself included), have some difficulty feeling wowed by it.