Most biographies of scientists focus on their character and personal life rather their work.
There are very few technical biographies, even of highly technical people. Readers won't understand the work of the scientist any better after reading through one of them.
Quantum Man by Lawrence Krauss specifically aims to be a solution to this regarding Richard Feynman. And even in this case the exposition needs to be so terse that only the highly technical reader will fully understand most aspects of Feynman's work in the correct context.
Do you know of any biography of Dirac that edges on "if a little too technical"? I would love to read that.
Two side notes:
1) Letters Of Note has some excellent content. Here are a few more letters that have been discussed on HN previously: http://news.ycombinator.com/item?id=1424324 and http://news.ycombinator.com/item?id=1045311
2) I'm a big Feynman fan, and several of my several friends are as well. We've read most of his biographies and autobiographies, and were recently surprised to find that a new biography came out a few months ago. It's supposed to be quite good, and has strong focus on Feynman's scientific accomplishments. http://www.amazon.com/Quantum-Man-Richard-Feynmans-Discoveri...
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