Models in physics

Abstract

In its most common use, the term ‘model’ refers to a simplified and stylised version of the so-called target system, the part or aspect of the world that we are interested in. For instance, in order to determine the orbit of a planet moving around the sun we model the planet and the sun as perfect homogenous spheres that gravitationally interact with each other but nothing else in the universe, and then apply Newtonian mechanics to this system, which reveals that the planet moves on an elliptical orbit. Views diverge about what sort of entity such a model is. Those focusing on the formal aspects of models regard them either as equations or set-theoretical structures, while those opposed to such an approach take them to be descriptions or abstract (yet non-mathematical) entities. A further question concerns the relation of models and theories. In some cases models can be derived from theory simply by specifying the relevant determinables in a theory’s general equations. But many models cannot be obtained from theory in this straightforward way, and some even involve assumptions that contradict the fundamental theory. The relation of models to their respective target systems is equally complex and fraught with controversy. Two influential proposals take the relation between a model and its target to be isomorphism or similarity, respectively. This, however, has been criticised as too restrictive, since many models seem not to fit this mould.

Pseudo software: A mediating instrument for modeling software requirements

“…Once approved, the requirements model is ultimately transformed into the real software. As with the use of models in science, a requirements model can be characterized by semantics, ontology, and epistemology (Frigg and Hartmann, 2006). The semantic aspect deals with the meaning the requirements, namely, what does the model represent?…”

“…In developing the pseudo software model, characterizations of models in science are examined in the context of requirements engineering, including semantics, ontology, and epistemology (Frigg and Hartmann, 2006). Pseudo software captures the essential information of the real software under construction, including presentation, navigation, input constraints, business logic, and test cases.…”

A community-based framework for aquatic ecosystem models

“…Mathematical models are one of the principal instruments of modern science, and are increasingly being acknowledged for their role in scientific understanding and ecosystem management practices (Frigg & Hartmann, 2006;Schmolke et al, 2010). The development and application of numerical aquatic ecosystem models has been a rapidly growing field in aquatic sciences, in particular since the 1990s, with progression of computer technology, increasing needs for quantitative management of aquatic environments and a desire for more quantitative approaches in ecology (Rigler & Peters, 1995).…”

Benefits and challenges in developing warship simulator based on DEVS formalism

“…Computer simulation has become a useful method of mathematical modeling of many natural systems in physics (computational physics), chemistry, biology, human systems in economics, psychology, and social science and in the process of engineering new technology, to gain insight into the operation of those systems, or to observe their behavior [1].…”