SYSTEM (Isolated)
| Collection | International Encyclopedia of Systems and Cybernetics |
|---|---|
| Year | 2004 |
|
Vol. (num.) |
2(2) |
| ID | ◀ 3373 ▶ |
| Object type | Methodology or model |
A system that makes no exchange of any kind with any environment .
As stated by I. PRIGOGINE and P.M. ALLEN such a system: “… whatever its nature, will approach thermodynamic equilibrium , a state
characterized by the maximum value of
entropy , that is of ” disorder “ (1982, p.5).
This is a largely abstract concept. Indeed it is the model
of a system rigorously submitted to the
2d law of thermodynamics .
By definition the isolated system does not absorb nor emit any energy , matter
or
information
and could thus not even be observed. While useful in clasical physics and chemistry, it can not be used in biology nor social sciences (nor even, in some cases in physical sciences). This explains why classical
thermodynamics
had to be extended during this century to
open
and
irreversible systems .
According to G. SOMMERHOFF: “An isolated physical system in the classical sense is determined by the initial
state ”. This means “that the current state
of the system can be expressed in terms of single-valued
functions
of the initial
state
and the
time ”. SOMMERHOFF gives the example of the pendulum, for which the isolated system model
does not take in account any friction or
disturbance , which, of course, are always acting on concrete systems .
The isolated system, furthermore is practically always linear
and generally
deterministic . G. SOMMERHOFF writes about this point: “In a state-determined system
every possible initial
state
determines a single line of
behavior
only. And although different lines of
behavior
may at one point or another fuse, they can never bifurcate” (1969, p.158).
The concept of isolated system is particularly confusing in the case of living
and
social systems . As stated by A. RAPOPORT: “an isolated system cannot be a living system
(at least not for long)” (1966, p.6).
The misunderstanding of this aspect, very common since DRIESCH vitalism until the 1930es, blocked partly the development of biology during half a century, with among exceptions, WOODGER and von BERTALANFFY's work.