Closed system

In thermodynamics, closed system refers to a “system” that is “closed”, meaning that it has a boundary that is "closed off" to the passage of matter, but not to energy, e.g. in the form of pressure boundary work or heat. [1]

Quotes
The following are related quotes:

“As to the scarcity of matter in a closed system, such as the earth, the issue may, in my opinion, prove in the end more critical than that of energy.”
Nicholas Roegen (1979), “Comments on the Papers by Daly and Stiglitz” (pgs. 98-99); cited by Julian Simon (1981) in The Ultimate Resource 2 (pg. 79) [2]

“The concept of ‘entropy’ is unquestionably valid and relevant for a closed container in the laboratory. It may also be relevant for any larger entity that can reasonably be considered a closed system. But it is quite unclear where the boundary should be drawn for discussions of the quantity of energy, or if there is any relevant boundary. It is clearly wrong to say that ‘as to the scarcity of matter in a closed system, such as the earth, the issue may, in my opinion, prove in the end more critical than that of energy’ (Roegen, 1979): the earth is NOT a closed system because both energy (from the sun) and matter (cosmic dust, asteroids, debris from many planets) constantly rain down on the earth. Perhaps the solar system will prove to be an isolated system for some period in the future, conceivably for the entire life of the human species. But even then, it will last perhaps seven billion years. And the chances would seem excellent that during that span of time humans will be in touch with other solar systems, or will find ways to convert the matter on other planets into the energy we need to continue longer. So, with respect to energy there is no practical ‘boundary’ surrounding any [economic] unit of interest to us. And without such a boundary, the notion of entropy in the large is entirely irrelevant to us.”
Julian Simon (1981), The Ultimate Resource 2 (pg. 79) [3]

See also
● Open system
● Isolated system

References
1. Perrot, Pierre. (1998). A to Z of Thermodynamics (pg. 42). Oxford: Oxford University Press.
2. (a) Roegen, Nicholas. (1979). “Comments on the Papers by Daly and Stiglitz”, in: Scarcity and Growth Revisited (editor: Kerry Smith) (pgs. 95-105). Johns Hopkins.
(b) Simon, Julian L. (1981). The Ultimate Resource 2 (§4: Grand Theory (txt), pgs. 77-83; quote, pg. 79) (txt) . Princeton University Press, 1996.
3. Simon, Julian L. (1981). The Ultimate Resource 2 (§4: Grand Theory (txt), pgs. 77-83; quote, pg. 79) (txt) . Princeton University Press, 1996.

External links
Closed system – Wikipedia.

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