A physical system is a collection of physical objects under study. The collection differs from a set: all the objects must coexist and have some physical relationship. In other words, it is a portion of the physical universe chosen for analysis. Everything outside the system is known as the environment, which is ignored except for its effects on the system.
The split between system and environment is the analyst's choice, generally made to simplify the analysis. For example, the water in a lake, the water in half of a lake, or an individual molecule of water in the lake can each be considered a physical system. An isolated system is one that has negligible interaction with its environment. Often a system in this sense is chosen to correspond to the more usual meaning of system, such as a particular machine.
In the study of quantum coherence, the "system" may refer to the microscopic properties of an object (e.g. the mean of a pendulum bob), while the relevant "environment" may be the internal degrees of freedom, described classically by the pendulum's thermal vibrations. Because no quantum system is completely isolated from its surroundings, it is important to develop a theoretical framework for treating these interactions in order to obtain an accurate understanding of quantum systems.
In control theory, a physical system being controlled (a "controlled system") is called a "plant".
See also
- Conceptual systems
- Phase space
- Physical phenomenon
- Physical ontology
- Signal-flow graph
- Systems engineering
- Systems science
- Thermodynamic system
- Open quantum system
References
- Belkind, Ori (2 February 2012). Physical Systems: Conceptual Pathways between Flat Space-time and Matter. Springer Science & Business Media. p. 1. ISBN 978-94-007-2373-3.
The notion of physical system is so ubiquitous it is mentioned in almost every work in physics. Scientists use the term, without much reflection, to refer to an aggregate of physical objects.
- Bunge, Mario (1967). Foundations of Physics. Springer Tracts in Natural Philosophy. Vol. 10. Berlin, Heidelberg: Springer Berlin Heidelberg. doi:10.1007/978-3-642-49287-7. ISBN 978-3-642-49289-1.
- Breuer, H.-P.; Petruccione, F. (2007). The Theory of Open Quantum Systems. Oxford University Press. p. vii.
Quantum mechanical systems must be considered as open systems
Further reading
- Bunge, Mario (13 March 2013). Foundations of Physics. Springer Science & Business Media. ISBN 978-3-642-49287-7. Retrieved 21 June 2023.
- Bunge, Mario; Mahner, Martin (2004). Über die Natur der Dinge: Materialismus und Wissenschaft (in German). S. Hirzel. ISBN 978-3-7776-1321-5.
- Halloun, Ibrahim A. (25 January 2007). Modeling Theory in Science Education. Springer Science & Business Media. ISBN 978-1-4020-2140-4. Retrieved 21 June 2023.
- Schmutzer, Ernst (29 August 2005). Grundlagen der Theoretischen Physik (in German). John Wiley & Sons. ISBN 978-3-527-40555-8. Retrieved 21 June 2023.
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A physical system is a collection of physical objects under study The collection differs from a set all the objects must coexist and have some physical relationship In other words it is a portion of the physical universe chosen for analysis Everything outside the system is known as the environment which is ignored except for its effects on the system Weather map as an example of a physical system The split between system and environment is the analyst s choice generally made to simplify the analysis For example the water in a lake the water in half of a lake or an individual molecule of water in the lake can each be considered a physical system An isolated system is one that has negligible interaction with its environment Often a system in this sense is chosen to correspond to the more usual meaning of system such as a particular machine In the study of quantum coherence the system may refer to the microscopic properties of an object e g the mean of a pendulum bob while the relevant environment may be the internal degrees of freedom described classically by the pendulum s thermal vibrations Because no quantum system is completely isolated from its surroundings it is important to develop a theoretical framework for treating these interactions in order to obtain an accurate understanding of quantum systems In control theory a physical system being controlled a controlled system is called a plant See alsoConceptual systems Phase space Physical phenomenon Physical ontology Signal flow graph Systems engineering Systems science Thermodynamic system Open quantum systemReferencesBelkind Ori 2 February 2012 Physical Systems Conceptual Pathways between Flat Space time and Matter Springer Science amp Business Media p 1 ISBN 978 94 007 2373 3 The notion of physical system is so ubiquitous it is mentioned in almost every work in physics Scientists use the term without much reflection to refer to an aggregate of physical objects Bunge Mario 1967 Foundations of Physics Springer Tracts in Natural Philosophy Vol 10 Berlin Heidelberg Springer Berlin Heidelberg doi 10 1007 978 3 642 49287 7 ISBN 978 3 642 49289 1 Breuer H P Petruccione F 2007 The Theory of Open Quantum Systems Oxford University Press p vii Quantum mechanical systems must be considered as open systemsFurther readingBunge Mario 13 March 2013 Foundations of Physics Springer Science amp Business Media ISBN 978 3 642 49287 7 Retrieved 21 June 2023 Bunge Mario Mahner Martin 2004 Uber die Natur der Dinge Materialismus und Wissenschaft in German S Hirzel ISBN 978 3 7776 1321 5 Halloun Ibrahim A 25 January 2007 Modeling Theory in Science Education Springer Science amp Business Media ISBN 978 1 4020 2140 4 Retrieved 21 June 2023 Schmutzer Ernst 29 August 2005 Grundlagen der Theoretischen Physik in German John Wiley amp Sons ISBN 978 3 527 40555 8 Retrieved 21 June 2023 This physics related article is a stub You can help Wikipedia by expanding it vte
