p.3 That the amount of information discarded during some process
is a measure of the complexity of its result may at first seem strange. Think of long division: to calculate
the quotient of two numbers one must calculate a number of multiples of the divisor as intermediate steps; once the
division has been completed, the results of these intermediate multiplications constitute information that is no longer
useful -- "junk" information. Animals cull useful information from useless as a simple prerequisite of the complex process
of staying alive... The position of the mosquito just eaten is no longer relevant to the future survival of the swift
[JLJ - a bird], and all the information generated in the process of catching that mosquito, once useful, now becomes
useless.
p.4 the computational complexity of a problem is proportional to the number
of elementary logical and arithmetical operations that must be performed to solve the problem starting from an a given set
of initial information.
p.31 The intuitive notion of complexity that we develop here is that complex
systems lie somewhere in the continuum between order and chaos.
p.35-36 In general, physical systems perform easily processes
that are difficult for a computer to simulate, for the simple reason that computers are designed to perform sequences of logical
operations, while systems in nature, though they may abide by logical rules, do not evolve step by step according
to Boolean algorithms.
p.51 In the course of a calculation, a computer performs two basic processes
over and over again. 1) It copies information from one place to another (e.g., from memory to the central processing unit,
or CPU, and vice versa). 2) It transforms information using logic circuits (e.g., taking the and of two bits, multiplying
two floating point numbers). [JLJ - 3) It uses the result of a calculation or the contents of a memory location to determine
the location of the next sequential command to be processed 4) Having located the next sequential command, it follows rules
to interpret the command, which might include the execution of one or several sub-commands, or waiting for an extended command,
such as multiplication, to finish]
