GEORGE JOHNSON

Fire in the Mind
Viking 1996

pg 12

...Just as nature abhors a vacuum, the mind abhors randomness. Automatically we see pictures in the stars above us; we hear voices in the white noise of a river, and music in the wind. As naturally as beavers build dams and spiders spin webs, people draw maps, in the sky and in the sand.

...(they) speculate about this most basic of human drives: the obsession to find and impose order. Whether the order we invent are geographic, religious, or scientific, inevitably, it seems, we come to identify the map with the territory, to insist that the lines draw a real......

pg 25

...Pushed up against this edge, science often retreats into platonism. Here on earth there may be no such thing as a perfect circle, but we recognise the rough approximations because we somehow have access to the perfect circle, the pure idea existing in a separate ectoplasmic realm. And so we are left with a duality between mind and matter, ideas and things.

Some followers of the information physics being pursued in Los Alamos, Santa Fe, and elsewhere suggest a way of bridging the divide: the laws of the universe are not ethereal, they say, but physical - made from this stuff called information, the 1s and 0s of binary code.

pg 110

In building a tower of abstraction, one must start with a foundation, those things that are taken as given: mass, energy, space, time. Everything else can then be defined in terms of these fundamentals. But gradually over the last half-century some scientists had come to believe that another basic ingredient was necessary: information.

A Shortcut Through Time
The Path to the Quantum Computer
New York 2003

pg 66

....Take the image of the Turing machine, the cartoon version of classical computation (pg. 54 .....Computation is simply a matter of taking an input string and converting it, according to the rules of the programme, into an output string.), and dispense with the read/write head altogether, so all that is left is the tape.

The result is what mathematicians call a cellular automaton or CA - a deceptively simple device that can generate surprisingly intricate behaviour. Start the tape to the battle of cells coloured black (1) or white (0). Then each cell interact with its neighbours according to a strict menu of rules: "If the two cells to your left are black and the two to your right are white, then you must turn white also." Or "If the pattern to your left is white-black-white and all want to your right is black-black-white, then you must turn black." Any number of variations can be imposed. Once the device is set in motion, the cells interact with their neighbours and, at each tick of the clock, the pattern evolves kaleidoscopically, a scintillating pattern of black and white.

This text explains, why a cellular automaton is a universal Turing machine

Mail to George Johnson: johnson johnson@santafe.edu

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