Closed system

This article covers the term in physics. For the business model, see closed platform .

As closed or isolated system a is physical system without interaction denoted by its environment.

thermodynamics

→ Main article : Thermodynamic system

In thermodynamics , a distinction is made between open, closed and closed (or isolated) systems.

A system that does not interact with its environment is defined as closed or isolated. It follows from this that it cannot exchange any energy with its environment , regardless of its appearance (e.g. radiation , matter , heat or mechanical work ). A closed system is therefore also adiabatic , its total energy constant. Since in reality there is no known possibility of complete isolation, this concept is an idealization, which, however, can be experimentally approximated on shorter time scales (in the range of hours and days), e.g. B. in a Dewar , so a vacuum jug .

Please note that there is a risk of confusion between the terms closed and closed . Colloquially, these terms are often used synonymously. In Anglo-Saxon literature there are only the terms closed for closed and isolated for isolated. It is therefore advantageous to only use the term in isolation .

Other areas

In other physical fields the term is sometimes used in a less strict sense. With regard to e.g. B. on electric charge is a closed system any system beyond the limits of which no charge is transported.

cosmology

The big bang model proposed in cosmology describes, depending on the mass and energy density, a universe that will collapse again in the distant future (closed) or a (open) universe that will expand forever. Current observations indicate an increasing expansion and thus an infinitely expanding universe. In both cases, the universe as a whole is an isolated system.

Many universes postulate theories that have not yet been confirmed by observations (e.g. string theory ). If energy can be exchanged between these, the universes would belong to open systems.

See also

• Open system
• Cutting principle

literature

• Richard P. Feynman: Feynman lectures on physics. Mechanics, radiation, heat 5th, improved edition, definitive edition. Oldenbourg, Munich / Vienna 2007, ISBN 978-3-486-58444-8 (= The Feynman Lectures on Physics , Volume 1).
• Paul A. Tipler: Physics. 3rd corrected reprint of the 1st edition. 1994, Spektrum Akademischer Verlag, Heidelberg / Berlin 2000, ISBN 3-86025-122-8 .
• Ludwig Bergmann, Clemens Schaefer: Mechanics - Acoustics - Warmth. In: Textbook of Experimental Physics. Vol. 1, 12th edition. Walter de Gruyter, Berlin 2008, ISBN 978-3-11-019311-4 .
• Rainer Müller: Thermodynamics: From dew drops to solar power plants . De Gruyter, 1 January 2014, ISBN 978-3-11-030201-1 .
• Dieter Meschede: Gerthsen Physics . Springer-Verlag, February 27, 2015, ISBN 978-3-662-45977-5 .