These are excerpts and elaborations from my book "The Nature of Consciousness"
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The Edge of Chaos The US computer scientist
Chris Langton (who organized the first Artificial Life conference in 1987)
showed that physical systems achieve the prerequisites for the emergence of
computation (i.e., transmission, storage, modification) in the vicinity of a
phase transition, at the edge of chaos ("Computation at the Edge of
Chaos", 1990).
When a system is in a highly ordered state, the transfer and modification of information becomes impossible. When a system in in a highly chaotic state, no pattern of information can persist over time. As systems become less orderer and less chaotic, a compromise is reached, whereby information can exist, can be manipulated, can be transferred. In technical terms,
information becomes an important factor in
the dynamics of cellular automata in the vicinity of the phase transition
between periodic and chaotic behavior, i.e. between order and chaos. The idea is that some
systems undergo transformations, and while they transform they constantly move
from order to chaos and back. This transition is similar to the "phase
transitions" undergone by a substance when it turns liquid or solid or
fluid. When ice turns into water, the atoms have not changed, but the system as
a whole has undergone a phase transition. Microscopically, this means that
atoms are behaving in a different way. The transition of a system from chaos to
order and back is similar in that the system is still made of the same parts,
but they behave in a different way. The state between order and
chaos (the "edge of chaos") is sometimes a very
"informative" state, because the parts are not as rigidly assembled
as in the case of order and, at the same time, they are not as loose as in the
case of chaos. The system is stable enough to keep information and unstable
enough to dissipate it. The system at the edge of chaos is both a storage and a
broadcaster of information. At the edge of chaos,
information can propagate over long distances without decaying appreciably,
thereby allowing for long-range correlation in behavior: ordered configurations
do not allow for information to propagate at all, and disordered configurations
cause information to quickly decay into random noise. A fundamental connection
therefore exists between computation and phase transition. The edge of chaos is where
the system can perform computation, can metabolize, can adapt, can evolve. In a
word: these systems can be alive. Basically, Langton proved that Physics can support
life only in a very narrow boundary between chaos and order. In that locus it
is possible to build organisms that will settle into recurring patterns
conducive to an orderly transmission of information. Langtons theory related phase transitions, computation and life: he built a
bridge to link together Thermodynamics, Information Theory and Biology. Likewise, the US physicist
Murray Gell-Mann argued that living organisms
dwell at the edge of chaos, as they exhibit order and chaos at the same time,
and they must exhibit both in order to survive. Living organisms are complex adaptive systems that retrieve
information from the world, find regularities, compress them into a schema to represent the world, predict the
evolution of the world and prescribe behavior for themselves. The schema may
undergo variants that compete with one another. Their competition is regulated
by feedback from the real world under the form of selection pressure. Disorder is useful for the development of
new behavior patterns that enable the organism to cope with a changing
environment. Back to the beginning of the chapter "Self-organization and the Science of Emergence" | Back to the index of all chapters |
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