When I wrote From Eternity to Here, I was faced with a perennial problem for pop-physics authors: how to write a book that will appeal to the aficionados (although not scientists themselves) who have already devoured everything Brian Greene and Lisa Randall have ever written, but also be understandable and interesting to folks who don't know much more about Einstein than the fact that he rarely combed his hair? I came across a short blog review that claims I wasn't entirely successful in balancing the competing requirements, and it might be a fair criticism.
But one small complaint is I'm not sure if he's quite exactly worked out his audience. Early in the book, I was starting to fear it would be a rehash of stuff I already knew. It's not. But there were some elementary rehashes that, frankly, I think if someone went into the book not having that knowledge already, they aren't going to be able to grok the rest. This is not a mathematically demanding book, but it is a conceptually demanding book, and I am not sure if someone who doesn't have some limited grounding in the mathematics side will be able to make it through the conceptual side without missing a lot.
The diagnosis is completely accurate. On the one hand, I do spend time going over the basics of relativity, quantum mechanics, and logarithms, in ways that hopefully make these ideas accessible to people who haven't ever tried to understand them before. On the other hand, the meaty middle section of the book is conceptually very challenging for almost everybody, even if you are a regular consumer of popular physics books. We are simply not used to thinking in ways that don't presume the arrow of time from the start, and some of the issues that arise are highly non-intuitive. I tried to keep things fun and engaging, but there's no question that certain pages of the book require careful thinking and brain work. What to do? I'm not sure that, given the material I wanted to cover in this book, there is much else one could do. Probably I could have had less about the basics of relativity, and moved what there is until later in the book. But although the central ideas are conceptually very challenging, I don't think they're actually inaccessible to anyone who is willing to put some thought into them, regardless of mathematical background. So I don't regret that I didn't write a leaner and more challenging book aimed only at the aficionados, although I appreciate that something along those lines might have been more focused. I think that the aficionados just have to get used to reading introductions to GR and QM from a wide variety of different books -- at least until those topics become part of the standard high-school curriculum.
