The Role of Theories, Laws, Hypotheses, and Models
COMMON MISCONCEPTION: A theory is an unproven idea, while a law has been proven correct. A theory will become a law when enough evidence supports it so that it is considered to be "proven".
REALITY: A scientific theory and a scientific law serve two very different purposes, and one can never become the other.
SCIENTIFIC LAW
A scientific law refers to a rule that describes a repeatable pattern in nature. It does not attempt to explain why the pattern exists or how it happens; a law is simply a statement that it will happen every time under a specific set of conditions. Scientific laws are useful because they allow scientists to make assumptions of truth about specific patterns. A law is considered to be “true” until an observation is made that does not follow the law.
HYPOTHESIS
While scientific laws are not concerned with why a pattern exists, that doesn’t mean that scientists aren’t interested in “why”. Much of the work of science is an effort to explain such patterns. This is why hypotheses are important. A hypothesis is a possible explanation of “why”.
SCIENTIFIC THEORY
When a group of closely-related hypotheses are confirmed through a significant amount of repetition and replication, it is possible to develop them into a scientific theory. A scientific theory is an explanation of observations or events that is based on a significant amount of research, debate, and confirmation. Scientific theories are important because they help us explain our world. They give us a foundation of knowledge to build on. However, scientific knowledge is TENTATIVE. This means that both theories and laws can be rejected or modified. If new evidence is discovered that disproves a theory, the theory can be changed to fit the new evidence. Theories are rarely discarded completely, but rather, they are tweaked so that they agree with the EMPIRICAL EVIDENCE.
A theory will NEVER become a law; just as an apple will never become an orange because they are two different things. Laws describe what happens in nature, and theories explain why things happen.
SCIENTIFIC MODEL - a representation of an idea, object, system, or process.
Scientific models serve two main purposes, to help scientists study a phenomenon or idea and to help scientists explain an idea or concept. Scientific models can include 3-dimensional representations of objects, drawings or diagrams, flow-charts, analogies, mathematical equations, or any other way that one might represent an idea, object, system, or process.