Knowing and Thinking Level 2

Models, Theories and Laws

Models, Theories and Laws in Science

A scientific model is a construct that explains an abstract or complex phenomenon and from which predictions can be made that can be verified. It can be a physical representation but it can also be mathematical. An example of a simple explanatory model for day and night would be the use of a globe for the Earth and a light source for the sun. The interplay of complex, varied and unpredictable events such as the weather are modelled with computers. Many scientific models are used to assist communication and understanding. Scientific modelling is also used to predict changes resulting from changes in atmospheric gases.

A scientific theory is an attempt to explain a phenomenon and that has substantial evidence from a number of experiments or fields that are all consistent. Scientific theories are not regarded as ‘facts’ but if contradictory data is obtained and verified, then the theory must undergo revision or be rejected. The Big Bang theory attempts to explain how the universe commenced; the Theory of Evolution through natural selection attempts to explain the diversity of life on Earth.

A scientific law is a statement of a relationship that can be verified experimentally (for example, Newton’s Second Law states that the greater the force acting on a given mass, the greater the acceleration of that mass). Scientific laws are regarded as facts.