We explain what an open system is, its characteristics and examples. Furthermore, closed and isolated systems.
What is an open system?
An open system is one whose fundamental feature is that allows the free exchange of information, matter or energy between its interior and the environment without presenting barriers or impediments to the flow. In this exchange, the system takes what it needs and lets out what it doesn't. Some examples of open systems are the human body and plants.
The concept of “open system” is used in different areas of human knowledge and is particularly studied by physics in thermodynamic systems that is, those portions of the universe that are isolated to be studied. From this point of view, systems are sets of elements that form a whole and are classified according to the level of exchange of matter and energy they have with the environment.
Thus, open systems differ from closed systems, which are those that can exchange energy, but never matter, with the environment. For example: an inflated balloon.
One of the main approaches to open systems emerged in 1956 the work of the Austrian biologist and philosopher Ludwig von Bertalanffy (1901-1972), and represents his particular contribution to the General Systems Theory, of much greater theoretical breadth.
According to von Bertalanffy, all systems are, to some extent, open systems. since the flow to and from the outside cannot be completely stopped, unless the system is empty, which is completely impossible (since it would no longer be a system).
Characteristics of open systems
The main characteristics of open systems are:
- They allow the free exchange of information between the interior of the system and the external environment.
- They should not be considered only as the sum of their parts, but the interrelation of the elements produces new qualities.
- They lack barriers or impediments to flow, or they have them, but only to a certain and limited amount.
- They differ from closed systems and isolated systems.
Examples of open systems
Some examples of open systems within thermodynamics are:
- living beings which are understood as open systems to the extent that they are constantly taking and returning matter and energy from the environment. Such is the case of the photosynthetic system of plants, which receives sunlight and uses it to synthesize sugars, releasing carbon dioxide into the environment in return.
- A cup of hot water which radiates its heat to the colder environment, until a thermodynamic equilibrium occurs between the inside and outside of the system. Furthermore, water can be poured, meaning it can also exchange matter.
- The engine of a car which needs gasoline to operate and, when it does, it releases gases resulting from combustion.
- a campfire which needs certain materials to be able to combust (such as wood or coal) and releases gases.
- an inflator which requires energy from the external environment to expel air to inflate a certain element, such as a wheel, a ball or a balloon.
- a turbine which uses a certain material (such as water or gases) to produce energy.
- a blender which allows food to be introduced and, through the electrical energy received from the environment, transforms it into another matter.
- a cup of tea which allows heat to be exchanged with the medium and also matter, such as water or tea threads.
Isolated systems and closed systems
Open systems differ from closed systems, which are those that They do not exchange information with the external environment, that is, they are closed on themselves . Because it is difficult to find systems that are absolutely closed in the universe, physics considers as “closed” those that only exchange energy with the outside, but not matter.
Some examples of closed systems are:
- An inflated balloon.
- A thermometer.
- A pressure cooker.
- A closed bottle.
- A light bulb.
For its part, An isolated system is one that is so far removed from other systems that it is impossible to interact with them. . They can also be systems that have impenetrable borders that limit exchange between inside and outside. There are no perfect isolating systems, but there are those capable of significantly reducing the exchange of information. For example: a neoprene suit.
References
- “Open, closed and isolated systems” in Psiberg.
- “Open system, definition and main characteristics” at the International University of Valencia.
- “Open system” on Wikipedia.
- “Thermodynamic system” in Wikipedia.
- “The human body as a thermodynamic system” in ETSAM.
