In nature there are physical systems which process energy and various materials and which thereby build up and maintain ordered structures. Examples of such systems are living organisms and ecosystems with living organisms in interplay with one another and with the non-living environment. Also in human settlements and societies a similar conversion of energy and materials is taking place.
Structural organization in matter is best described in information theoretical terms. Furthermore, the systems often have control systems which process information. This information is physically tied to relatively small amounts of energy and matter. An important example is the genetic information in living organisms.
Energy, materials, and information is denoted physical resources.
Physical resource theory is the science dealing with physical resources and their conversion in various systems. The systems can be societal (e.g., technical, such as energy conversion systems or an industrial process), geophysical (e.g., the atmosphere or a mineral deposit), or ecological (e.g., an ecosystem or an organism). Special attention should be given to the conversion of physical resources in societies. This has to be studied with reference to human needs, availability of resources and the possibilities of incorporating these conversions in the natural system. Another important task for physical resource theory is to develop methods to optimize resource conversion processes. The systems are described and analyzed by means of the methods of mathematics and the natural sciences.
See further: Dept. of Physical Resource Theory, Chalmers University of Technology, Göteborg, Sweden.