We explain the difference between an open, closed and isolated system, the relationship of each one with the environment and its characteristics.
What is the difference between an open, closed and isolated system?
To understand the difference between an open system, a closed system and an isolated system, we must first understand what we mean by “system”. As the dictionary defines it, A system is a set of ordered and interrelated things that contribute to a goal.
That is, a system is an organized whole, a notion that applies both to certain sets of organs in the body, or to the entirety of a natural ecosystem, as well as to different phenomena and air temperatures in the atmosphere. Any segment of the universe that we decide to study in itself, ignoring the rest and focusing on its internal relationships, is a system.
This notion is extremely useful in physics, since through a systemic look we can identify the energetic and material phenomena that occur around us.
Thus, it is common to talk about physical systems, such as thermodynamic systems, in which there is an internal flow of matter and energy, which can be more or less linked to the environment. That is to say, A system can be more open or more closed, depending on how much information enters and leaves it. The information that circulates can be, for example, matter and/or energy.
Thus, we have three main types of physical systems: open, closed and isolated.
- Open systems. They are those that freely exchange matter and energy with the outside. For example, our bodies themselves are systems in continuous exchange with the environment: oxygen and food enter them, and waste substances, such as CO, are expelled.2 or ammonia from urine. Additionally, we continually lose heat when the environment is colder, and we lose moisture (water vapor) with every breath we take.
- closed systems . Yes are those that freely exchange energy (but not matter) with their environment. This energy can be in the form of heat, light or work. For example, a light bulb is a closed system in which not a single particle of matter enters or leaves, but electricity enters and light energy is extracted in exchange.
- Isolated systems . They are those that do not exchange matter or energy with the environment either because they are very far from any other system or because they have barriers that reduce (or, ideally, prevent) the transit between inside and outside. For example, a thermos for hot water is designed to delay as much as possible (preventing it entirely is impossible) the cooling of the liquids inside, thus minimizing the heat loss of the substance.
We must insist that Strictly speaking, there is no totally isolated system in the universe. All systems exchange information with their environment to some extent, although in some cases in negligible quantities or simply in such a way that it can be ignored for the study of the system itself.
Continue with: Laws of thermodynamics
References
- “Physical system” in Wikipedia.
- “Open system” on Wikipedia.
- “Closed system” on Wikipedia.
- “Isolated system” on Wikipedia.
- “Thermodynamic system” at the Polytechnic University of Madrid (Spain).
- “Types of systems” (video) in Ticmas Educación.
- “System” in the Language Dictionary of the Royal Spanish Academy.
