This is a biography of the mathematician and engineer Claude E. Shannon (1916–2001). It’s not a scientific biography, although it does have good explanations, in layman’s terms, of the areas he worked in. It gives a good picture of his personality and his eccentricities, slanted a little bit toward the latter.

Shannon was something of a prodigy, although unlike most prodigies he worked in many fields rather than putting all his effort on one. He graduated from the University of Michigan at age 20 with bachelor’s degrees in math and in electrical engineering. His first published work appeared in the *American Mathematical Monthly* when he was an undergraduate: a solution to elementary problem E58, a cryptarithm. He then went to graduate school at MIT. His master’s thesis showed how to apply Boolean algebra to the design of electrical circuits. This thesis was later described by the psychologist Howard Gardner as “possibly the most important, and also the most famous, master’s thesis of the century.” He received his PhD at the age of 24 for work in a totally different field, mathematical genetics. He then spent a year at the Institute for Advanced Study.

Shannon had a wide-ranging intellect and was interested in all kinds of things. His career was at Bell Labs and at MIT, both of which encouraged him in this. He was also a tinkerer all his life, and had a well-stocked home workshop where he often built gadgets to try out his theories and interests. One of the best known is Theseus, a mechanical mouse that could solve a maze and remember the solution. He did classified work during World War II on encryption and on gun control. In the scientific world he is best known for his foundational work in information theory, where he repurposed the physics term entropy to measure uncertainty in probability distributions (he called his home at MIT Entropy House). He developed some of the earliest ideas in chess-playing machines (and built a simple one). He devised a scheme to win at roulette by timing the wheel and observing irregularities (he built the first wearable computer to record the observations unobtrusively). He went through a period late in life of studying the stock market, although his approach was old-fashioned value investing and not very technical; he made a lot of money on stocks, but it appears he did this by investing in start-up companies where he knew the people and the technology and could make a good evaluation of the company’s prospects. He was fascinated by juggling and by unicycles, and often practiced both simultaneously, sometimes riding down the halls of Bell Labs.

Two good related books are Gertner’s *The Idea Factory: Bell Labs and the Great Age of American Innovation* (Penguin, 2012), that contains a lot about Shannon’s work at Bell Labs; and Nahin’s *The Logician and the Engineer* (about Boole and Shannon, but more technical than the present book).

Allen Stenger is a math hobbyist and retired software developer. He is an editor of the Missouri Journal of Mathematical Sciences. His personal web page is allenstenger.com. His mathematical interests are number theory and classical analysis.