THEORETICAL PHYSICS: ON PHYSICS AND THE REAL WORLD

The following points are made by George F.R. Ellis (Physics Today 2005
July):

1) Physics is the model of what a successful science should be. It provides
the basis for the other physical sciences and biology because everything in
our world, including ourselves, is made of the same fundamental particles,
whose interactions are governed by the same fundamental forces. It's no
surprise then, as Princeton University's Philip Anderson has noted, that
physics represents the ultimate reductionist subject: Physicists reduce
matter first to molecules, then to atoms, then to nuclei and electrons, and
so on, the goal being always to reduce complexity to simplicity. The
extraordinary success of that approach is based on the concept of an
isolated system. Experiments carried out on systems isolated from external
interference are designed to identify the essential causal elements
underlying physical reality.

2) The problem is that no real physical or biological system is truly
isolated, physically or historically. Consequently, reductionism tends to
ignore the kinds of interactions that can trigger the emergence of order,
patterns, or properties that do not preexist in the underlying physical
substratum. Biological complexity and consciousness -- as products of
evolutionary adaptation -- are just two examples. Physics might provide the
necessary conditions for such phenomena to exist, but not the sufficient
conditions for specifying the behaviors that emerge at those higher levels
of complexity. Indeed, the laws of behavior in complex systems emerge from,
but are to a large degree independent of, the underlying low-level physics.
That independence explains why biologists don't need to study quantum field
theory or the standard model of particle physics to do their jobs.

Full Text at ScienceWeek
http://scienceweek.com/2005/sw050916-6.htm

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Posted by
Robert Karl Stonjek