javamanjoe/spirit

TOR NORRETRANDERS 'THE USER ILLUSION'. BOOK REVIEW. The Danish mathematician Tor Norretranders has an important thesis: that mind is more than we see. And he has an intriguing sub-thesis: that this is a ubiquitous property in nature. He starts by introducing entropy, and its relationship to information.
James Maxwell showed a flaw in the law of entropy with his imaginary "demon", an intelligent being who manages to separate fast molecules and slow molecules in two separate rooms and therefore create a temperature differential without doing any real work. Maxwell's demon was meant to prove that the law of entropy is valid only "statistically". And it seems to refer more to our intellectual limitations (we are not as smart as the demon) than to a property of the universe. Leon Brillouin started solving the paradox when he discovered that information is a material quantity: information comes from a physical measurement. Wojcieh Zurek finished solving the paradox in 1990 by linking entropy, algorithmic complexity and Turing's machine.
Norretranders then gives a quick overview of the development of mathematical thought in our century: Hilbert, Goedel, Turing, all the way to contemporary algorithmic complexity.
The concept that captures his imagination is "exformation": what is discarded during communication of information.