The first time I read this I was too young, but re-reading it recently I was drawn to the complex characters who have to negotiate a self and a career and a love which do not necessarily have the same needs. As an academic, I and nearly all of my colleagues have had to negotiate the tricky business of solving the "two-body problem" without destroying everything else along the way. And, the physicist in me just plain loves the title.
On the plus side, this is a well-constructed generational novel of great depth and an extremely ambitious set-up. There are extremely compelling story elements and a historical aspect that is vividly depicted. The downside is that there are few characters that I was able to really like, and those that I did were minor figures in the narrative. In addition to that, it really is largely a rip-off of a very real life story. The dream sequence is extremely irritating (you'll know what I mean if you read it), and the book doesn't exactly come to a complete conclusion. In the end, the writing warrants four stars, but it is not a book I could say I love. That being said, it did win the Pulitzer, so is a fairly important contribution to literature.