What is a principle or law in scientific terms?

In scientific terms, a principle or law is considered to be a statement or formula that has consistently proven valid through repeated testing and scientific inquiry over time. This means that a principle is not just an isolated observation but is supported by a substantial body of evidence that demonstrates its reliability and applicability across various situations. Laws, such as the laws of thermodynamics or Newton's laws of motion, represent fundamental truths about the natural world and provide a framework for understanding and predicting phenomena in science.

The other options represent concepts that do not align with the definition of a scientific principle or law. A hypothesis, for instance, is an initial educated guess that requires rigorous testing and experimentation to assess its validity and is not considered a principle until it has been substantiated by evidence. Similarly, a guess lacks the empirical support needed to elevate it to the status of a scientific principle. Lastly, a variable refers to factors that can change in an experiment but do not provide the enduring truths that principles or laws represent.