# Jimmy Soni & Rob Goodman - A Mind at Play

**Jimmy Soni & Rob Goodman** 2012. *A Mind at Play. How Claude Shannon Invented the Information Age*. ebook. New York: Simon & Schuster, 384 pp.

This biography of Claude Shannon makes him seem a lot like Paul Dirac. A true eccentric genius. Contemporary of Johnny von Neumann, Alan Turing et al, who all knew one another.

As most readers would want, the book has a much stronger focus on Shannon’s research than on Shannon himself. And when the authors do focus on Shannon, it is most often on career and idiosyncracies (eg his enthusiasm for unicycle riding and juggling). It is only late in the book that we suddenly discover that Shannon now has two children. Probably there will be another biography one day that filles some of these gaps. This one will do me though - lots of people have children, but not many lay the foundations for information science.

Shannon defined channel capacity - bits per second and demonstrated the relationship between capacity, bandwidth and signal to noise ratio, a relationship to which engineers are beholden to.

But to me this might have been Shannon’s great contribution in a nutshell:

What does information really measure? It measures the uncertainty we overcome

Did Shannon know about Bayes? (Perhaps not, at least not mentioned in this book.)

Shannon’s advice to approaching problems (in the words of the authors):

Simplify … excise everything from a problem

exceptwhat makes it interesting

Aside from the information theory and mathematical background central to Shannon, there are some other memorable observations:

There are passionate scientsts who are almost overcome by the abundance of the world, who are gluttons for facts; and then there are those who stand a step back from the world, their apartmess a condition of their work. Shannon was one of this latter kind …

[in the context of Shannon’s brief dabble in genetics at Cold spring Harbor]

Demand for naturalists and butterfly nets had cratered; biology, like computer building, demanded mathematicians.

Of the famous Bell Laboratories, where Shannon spent the bulk of his career (not the last part), their president said:

There were two kinds of researchers … those who are being paid for what they

usedto do, and those who are being paid for what they weregoingto do. Nobody was being paid for what they were doing now.