When it comes to scientific terminology, people often use the terms “theory” and “law” interchangeably, but they actually have different meanings. In this article, we will discuss the difference between a scientific theory and a scientific law.

Scientific Theory

A scientific theory is a well-substantiated explanation of some aspect of the natural world that is based on empirical observations, experiments, and data. It is a framework for understanding how and why things work the way they do.

Theories are developed through a process of hypothesis testing and experimentation. They are constantly being revised and refined as new evidence becomes available.

Examples: The theory of evolution, the germ theory of disease, the atomic theory

Scientific Law

A scientific law is a statement that describes an observed phenomenon without explaining why it happens. It is a concise summary of a pattern that has been observed repeatedly in nature. Laws are based on empirical evidence and are often expressed mathematically.

Examples: Newton’s laws of motion, Boyle’s law, the law of conservation of energy

Differences Between Theory and Law

Explanation vs. Description
The most significant difference between a theory and a law is that theories explain why something happens while laws describe what happens. A theory provides an explanation for observed phenomena while a law summarizes patterns in data.

Evidence Required
Theories require more evidence to support them than laws because they attempt to explain why something happens rather than just describing what happens. Theories must be supported by numerous lines of evidence before they can be considered valid.

Theories can be falsified if new evidence contradicts them or if they fail to predict future observations accurately. Laws cannot be falsified because they simply describe what has been observed in nature.


In summary, a scientific theory is an explanation of a natural phenomenon that is based on empirical evidence and subject to revision as new evidence becomes available, while a scientific law is a concise summary of patterns observed in nature. Both theories and laws are essential to our understanding of the natural world, but they serve different purposes. Understanding the difference between the two can help you better appreciate the scientific method and the role it plays in our lives.