System
Chapter 1 - Worldview
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Welcome to the System page
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Defining and understanding systems in science (physics & biology), technology, and society as sets of interconnected parts that comprise a cohesive whole is essential. A system can be described or modelled as having a boundary between itself and the rest of the world around it. Systems can be connected, contingent on one another, or work together causally. Much of the goal of science is to understand systems so that they can be explained and modelled to make predictions.
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Core ideas
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Open- and closed systems
- An open system can exchange both energy and matter with its surroundings.
- An open system allows matter and energy to enter and leave it. It is also significantly interconnected to other systems or the world around it.
- A closed system can only exchange energy with its surroundings, no matter what.
- A unique form is an isolated system that cannot exchange matter or energy with its surroundings.
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Environment / context
- Biologic open systems require energy and matter from outside to maintain their balance/homeostasis
- In addition, social systems need support from 'superordinate systems' to preserve their stability
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Examples of systems
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Physical systems
- A cup of coffee is an open system, because heat and water vapor can be lost to the air.
- Refrigeration and air conditioning systems are illustrations of closed systems, where the refrigerant flows in a closed cycle, undergoing phase changes that remove heat from a designated area.
- A perfect isolated system is hard to come by, but an insulated drink cooler (thermos) with a lid is conceptually similar to a truly isolated system.
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Biological systems
- A plant is an open system because of the rate at which matter and energy enter and leave the plant. Plants absorb sunlight, water, and carbon dioxide to release oxygen and store glucose throughout the day.
- Analogously, animals are open systems.
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Social systems
- Social systems are open systems
- For instance, social systems are open systems, characterized by a patterned series of interrelationships existing between individuals, groups, and institutions. These relationships form a coherent whole, with internal institutionalized structures and rules regulating behaviour. Understanding these social systems can provide valuable insights into human behaviour and societal dynamics
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Deep dive
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General systems theory
Ludwig von Bertalanffy (19 September 1901 – 12 June 1972) was an Austrian biologist known as one of the founders of general systems theory (GST). This is an interdisciplinary practice that describes systems with interacting components, applicable to biology, cybernetics and other fields. Bertalanffy proposed that the classical laws of thermodynamics might be applied to closed systems but not necessarily to "open systems" such as living things. His mathematical model of an organism's growth over time, published in 1934, remains a cornerstone of our understanding of systems today.
| A system is closed if no material enters or leaves it; it is open if there is import and export and, therefore, change of the components.
So far, physics and physical chemistry have been concerned almost exclusively with processes in closed reaction systems, leading to chemical equilibria. A closed system must, according to the second law of thermodynamics, eventually attain a time-independent equilibrium state, with maximum entropy and minimum free energy, where the ratio between its phases remains constant. A closed system in equilibrium does not need energy for its preservation, nor can energy be obtained from it. To perform work, however, the system must be, not in equilibrium, but tending to attain it. . Living systems are open systems, maintaining themselves in exchange of materials with environment, and in continuous building up and breaking down of their components. The cell and the organism as a whole, however, do not comprise a closed system, and are never in true equilibrium, but in a steady state. We need, therefore, an extension and generalization of the principles of physics and physical chemistry, complementing the usual theory of reactions and equilibria in closed systems, and dealing with open systems, their steady states, and the principles governing them. An open system may attain (certain conditions presupposed) a time-independent state where the system remains constant as a whole and in its phases, though there is a continuous flow of the component materials. This is called a steady state. Steady states are irreversible as a whole, and individual reactions concerned may be irreversible as well. In an open reaction system, irrespective of the concentrations in the beginning or at any other time, the steady state values will always be the same, being determined only by the constants of reactions and of the inflow and outflow. . Entropy must increase in all irreversible processes. Therefore, the change in entropy in a closed system must always be positive. But in an open system, and especially in a living organism, not only is there entropy production owing to irreversible processes, but the organism feeds, to use an expression of Schrödinger's, from negative entropy, importing complex organic molecules, using their energy, and rendering back the simpler end products to the environment. Thus, living systems, maintaining themselves in a steady state by the importation of materials rich in free energy, can avoid the increase of entropy which cannot be averted in closed systems. Entropy may decrease in open systems. Therefore, such systems may spontaneously develop toward states of greater heterogeneity and complexity. Generally speaking, the basic fundamental physiological phenomena can be considered to be consequences of the fact that organisms are quasi-stationary open systems. Metabolism is maintenance in a steady state. . Every organic form is the expression of a flux of processes. It persists only in a continuous change of its components. Every organic system appears stationary if considered from a certain point of view; but if we go a step deeper, we find that this maintenance involves continuous change of the systems of next lower order: of chemical compounds in the cell, of cells in multicellular organisms, of individuals in superindividual life units. It was said, in this sense that every organic system is essentially a hierarchical order of processes standing in dynamic equilibrium. ... We may consider, therefore, organic forms as the expression of a pattern of processes of an ordered system of forces. . Finally, growth, development, senescence, and death represent the approach to, and slow changes of, the steady state. (1) |
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| (1) | The Theory of Open Systems in Physics and Biology - Ludwig von Bertalanffy - Science - January 13, 1950, Vol. 111 |
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