Isolated system

As a closed system, a system with no interaction with their environment is referred to.


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

When completed, or isolated, a system is defined, which can not exchange energy, regardless of their appearance (eg, radiation, matter, heat or mechanical work ), with its environment. A closed system is thus adiabatically, its total energy constant. Since in reality no way complete isolation is known, it is this approach represents an idealization that can be realized, however, approached experimentally on shorter time scales (in the range of hours and days ), eg in a Dewar vessel, ie a jug.

To note the confusion of terms is closed and locked. Colloquially, the terms are often used interchangeably. In the Anglo-Saxon literature, only the terms exist for closed closed and isolated for isolated. It is therefore advantageous to use only isolated the term.

Other areas

On other physical areas, the term is sometimes used in less strict sense. With respect to, for example, electric charge, a closed system, any system on the boundaries, no charge will be transported.


The method proposed in cosmology big bang model describes, depending on the mass and energy density of a collapsing again in the distant future (completed ) or forever expanding (open ) universe. Current observations point to an increasing expansion and thus an infinitely expanding universe. In both cases the universe as a whole is an isolated system.

So far not confirmed by observations theories (eg string theory ) postulate many universes. If it can be exchanged between these energy universes would be part of open systems.

  • Thermodynamics