Definition of a Scientific Law
A scientific law is a concise statement, based on repeated experimental observations, that describes an aspect of the universe. It typically summarizes a vast number of empirical observations and is often expressed as a mathematical equation or a verbal statement. Unlike a theory, a law describes *what* happens under certain conditions, rather than explaining *why* it happens.
Key Characteristics of Scientific Laws
Scientific laws are considered universally applicable and consistently predictive, meaning they imply that a specific outcome will always occur given the same initial conditions. They are typically short, factual, and derived from consistent patterns in observed data. Laws are accepted as true because they have been repeatedly verified and have no known exceptions under the specified conditions.
Example: Newton's Law of Universal Gravitation
A classic example is Newton's Law of Universal Gravitation, which states that any two bodies in the universe attract each other with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers. This law accurately predicts the gravitational force between objects but does not explain the underlying mechanism or origin of gravity itself.
Distinction from Scientific Theories
It is crucial to differentiate scientific laws from scientific theories. While both are fundamental to science, a law describes an observed phenomenon (the 'what'), whereas a theory explains *why* the phenomenon occurs (the 'how' and 'why'). Theories are broader, more complex explanatory frameworks that can encompass and interpret multiple laws and observations.