Definitions


På svenska

Some of the definitions used during the course:

(In the left column, you can find further explanatory texts linked)

Attractor state

The state towards which a system spontaneously moves.

Chaotic

A system that is deterministic but is in a regime such that its state is not predictable.

Closed system

  1. A system, over the border of which only energy can be transmitted. The only living system that can be described as closed in this respect is the ecosphere itself. (A definition often used by systems theoreticists )

  2. A system over the borders of which neither energy nor mass can be transmitted. (A more strict definition often used by physicists)

Dissipative systems

Open systems that maintain or increase their organisation through exergy destruction.

Ecosphere

The living system of the Earth, supersystem to the ecosystems.

Emergence

The development of features of whole systems that are not deducible from the features of the constituting subsystems.

EMergy

The energy of one type required for a flow or storage. (What lies ‘behind’ that flow or storage. H.T. Odum)

Entropy

A measurement of  the uncertainity in a situation (information transfer, energy states etc.). The term should be used with care since it is not well defined for systems far from thermodynamic equilibrium.

Exergy

A term used to describe differences in energy quality. The exergy content of a system indicates its distance from thermodynamic equilibrium. The higher the exergy content, the farther from thermodynamic equilibrium. More about exergy here.

Far-from-equilibrium -systems

Systems in the non-linear phase far from thermo­dynamic equilibrium, i.e., whirlpools and all living systems.

Health, Ecosystem-

The ability to cope with stressors and to maintain its self-organisational ability.

Health

The ability to maintain relations and functions.

Holarchy

A hierarchy of holons. Nested systems

Holon

A functional unit that often is a part of a larger unit (the supersystem) and often constitutes of other holons (subsystems). Derives from the greek holos: whole (Koestler).

Information

A difference that makes a difference (Bateson)

Information, Working

There is a difference between working information and resting information. The difference between these concepts is understood when considering the information that is carried by the expressed and unexpressed part of the genotype. The resting information has no immediate effects on the system, but could have it in the future or in the history of the system. The working information has a real effect on the organization of the system.

Integrity, Ecosystem-

The capacity to maintain organisation. Measurements of organisation (ascendency, Ulanowitcz) can be a measure of integrity.

Integrity

The capacity of a system to maintain its individuality.

Isolated system

  1. A system over the border of which nothing, neither mass nor energy can be transmitted.

  2. By some authors, this term is not used. Instead, the term closed is used for this situation. See above on Closed systems

Mechanic equilibrium

Opposite forces balancing each other. Cf. Steady state

Nested systems

Systems that constitutes of subsystems. Often, they are themselves subsystems in a holarchic series.

Open system

A system, over the border of which both energy and mass can be transmitted.

  1. Practically all living systems are open .

  2. All living systems are open (see above on Closed systems).

Order

The possibility to predict a certain property of a system by extra- or interpolations of observations — regularity. See diagram

Organisation

Relations between units that define their relations to the supersystem. (see diagram) Information plus regulation. The organisation is limited by the communication between the subsystems (v. Bertalanffy). Increasing organisation can thus make the system fragile and increase the risk for collapse (Holling).

Resilience

  1. The distance a system can departure from an attractor state and still be able to return to it. The width of the attractor basin.

  2. The time a system demands for its return to the original attractor after a perturbation.

Self-organisation

The spontaneous organisation change of a dissipative system toward an attractor state.
See also this link

Steady-state

Dynamic stability, or dynamic equilibrium. Opposite processes balancing each other. Cf. Mechanic equilibrium. Example: The HEAP-trap

Structure

Organization plus the material components which are organized. Structure is operational  information.

System

A collection of components (that we are interested in) that are more related to each other than to components outside.

Teleological

A goal-oriented process by a system conscious of the goal. (I am walking upwards the ladder to the attic)

Teleonomic

A goal-oriented process by a system unconscious of the goal. (I am walking the ladder)

Thermodynamic equilibrium

From this state, no spontaneous changes occurs. No exergy is available. The ultimate attractor state. There is a differentiation between internal equilibrium (no difference in state variables within the system) and external equilibrium (no difference between state variables of the system and its environment).

Thermodynamic laws

Are considered to be three, but have since 1965 - 66 been replaced by a single: (The Unified Principle of Thermodynamics). The naught (or third) law states that there is no temperatures below 0º K (This has been disproved, in lasers it is not valid).

  1. The first law states that energy can not be destroyed nor created.

  2. The second law (often referred to as the 'entropy' law) states that the quality of energy is degraded in each spontaneous change.

Unified Principle of Thermodynamics

A condensation of the laws of thermodynamics. It was formulated by Keenan and Kestin 1965, 1966. When an isolated system  performs a process after the removal of a series of internal constrains, it will reach a unique state of equilibrium: this state of equilibrium is independent of the order in which the constraints are removed. This formulation indicates a direction of a process. From this principle, it is possible to deduce both the classical laws of thermodynamics and principles for the thermodynamics of far-from-equilibrium systems (Schneider and Kay).

 



Forgot where
you saw it?



------------------------------------
Do you want news from the Holon site?
Insert your e-mail address below!


Updated:
2013-01-06