Robert read and liked Manny's review of QED: The Strange Theory of Light and Matter:

"Sometimes, it's too late, but that makes you do it better. You probably imagine that this book is a physics text. Well, it is, but that that's not what it really is. Really, it's a love letter to a dead woman. Feynman says in his introduction that hi...more Sometimes, it's too late, but that makes you do it better. You probably imagine that this book is a physics text. Well, it is, but that that's not what it really is. Really, it's a love letter to a dead woman. Feynman says in his introduction that his friend Alix Mautner had always wanted him to explain quantum electrodynamics to her so that she could understand it, and he'd never gotten around to doing that. Now it was too late. But, somehow, you can see that that only made him want to do it, not just well (he did everything well), but perfectly. If the book was perfect, that would make up for its appearing after Alix was no longer around to read it. It may seem like an odd formula, but it worked for Dante, and it also worked for Feynman.

So, to get maximal enjoyment from QED, you should pretend that you're a mysterious dead woman, sitting in Heaven and reading this missive from your dear friend. You're smiling and shaking your head. It's so Dick! You're dead, and you've been told the secrets of the Universe, so of course you no longer need it - but the little flourishes are all his. So clever and thoughtful of him to take out the complex numbers! After all, arrows are exactly the same as complex numbers, and you can add and multiply them in an obvious way... or at least, he makes you feel it's obvious. How else would you do it?

He's found such a nice entry point, thinking about the way glass reflects monochromatic light. The fact that a tiny difference in thickness makes a huge difference to the proportion of light reflected simply demands an explanation, and the arrows are the only way to make sense of the data. And then, when you start considering how mirrors and lenses work, the Feynman path-integral happens by itself. Of course! It's the only possible solution. When you were alive, you would have loved this.

The rest of it all fits together too. You'd always wondered what those diagrams meant that he kept drawing! They're quite trivial, once you've absorbed a few straightforward details, like positrons being electrons travelling backwards in time. And you would have seen what he was referring to when he said that theory agreed with practice to ten decimal places. And even why it's so much harder to do calculations with subatomic particles than with electrons. The coupling coefficient is much bigger! Naturally. How come you never thought of that while you were still mortal?

At the end, he's even included a few questions about things he hasn't figured out yet. You can't wait for him to arrive, so you can give him the answers. It'll be so funny to see his face when you tell him why a muon is like an electron, only with more mass. He'll wonder how he could ever have missed it.
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PS I would just like to make it clear that I'm no way implying that anything improper happened between Richard Feynman and Alix Mautner. As far as I'm aware, their relationship was as chaste as the one between Dante and Beatrice. Muses often seem to work most effectively like that.
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