ABSTRACT
We usually think of a model as an ideal pattern for some project, such as an architect’s scaled-down mock-up of the design of a new shopping mall, or an attractive person’s display of the latest fashion in cosmetics or clothing. A model can demonstrate how things work, such as a small-scale working replica of a steam engine, or how something is done, such as a therapist showing an anxious client how to deal safely and calmly with a phobic situation. Similarly, a theoretical model is a simplified pattern that shows how something might look or how a process might work. For example, in the early 1900s physicists described a theory of atomic structure—a positively charged nucleus surrounded by a system of electrons—that served as a model of the atom.
