A scientific theory is a well-substantiated explanation of some aspect of the natural world that is based on a body of evidence gathered through repeated observation, experimentation, and testing using the scientific method. It organizes and explains multiple facts and observations, and it is capable of making predictions that can be tested by further observations or experiments
. Unlike the everyday use of the word "theory," which often implies a guess or speculation, a scientific theory is a reliable, comprehensive framework that has withstood rigorous scrutiny and is widely accepted within the scientific community. It differs from a scientific fact, which is a single observation, and from a scientific law, which describes relationships among facts but does not explain why they occur. Theories provide the explanatory structure behind laws and facts
. Scientific theories are continually tested and refined as new evidence emerges. They are not absolute truths but the best explanations available based on current evidence. If new data contradict a theory, it may be modified or replaced by a better theory. Examples of well-established scientific theories include the theory of evolution, the atomic theory of matter, and the germ theory of disease
. In summary, a scientific theory is:
- An explanation of natural phenomena supported by extensive evidence.
- Tested repeatedly and confirmed through observation and experiment.
- Capable of making predictions.
- Different from a hypothesis (a tentative idea) and a scientific law (a descriptive relationship).
- Open to revision as new evidence becomes available
