|Formal Sciences||Life Sciences||Physical Sciences|
The term "science" commonly refers to a set of methods of investigation leading to knowledge of the natural world. These methods include systematic observation, the formation of hypotheses and theories, and the construction of experiments to test these theories and hypotheses. The life sciences are concerned with the study of living organisms, including human beings, and the manner in which they interact with their natural environments. The physical sciences investigate the underyling materials and processes of the universe, ranging from the subatomic to the intergalactic. The formal sciences study the symbol systems used to express ideas in the other sciences and to express ideas about these symbol systems themselves.