ENVELOPE
| Collection | International Encyclopedia of Systems and Cybernetics |
|---|---|
| Year | 2004 |
| Vol. (num.) | 2(1) |
| ID | ◀ 1119 ▶ |
| Object type | Methodology or model |
The external surface that limits the volume of space occupied by a system.
Differently, in mathematical terms, an envelope is a curve that is tangential to every member of a family of lines or curves.
This abstract concept (still defined in different terms by R. ACKOFF and EMERY, 1972, p.17) has been used by F. ZWICKY to describe higher levels of integration of processes at lower levels (Morphognetic worldview, 1971), and F. MEYER in a dynamic meaning, to describe acceleration in general evolution (1954).
In a more physical sense, close to “boundary”, composite systems, which are continuously shifting in their composition and form, do not have any permanent envelope. It is also impossible in most cases, to describe an envelope for an ecosystem or a human organization.
Only quite strongly integrated systems may be said to have a well definable envelope, as for example the skin of an animal.
The enveloppe is at the same time a boundary that separates the system from its environment and an interface through which exchanges with the same (inputs, outputs) take place. It is sometimes fractalized, which makes it difficult to define its limits.