* Extensive empirical evidence: This means a large amount of data collected through experiments, observations, and measurements, consistently supporting the law. The more evidence there is, and the more diverse the sources, the stronger the support for the law.

* Repeatable experiments: The experiments that produce the evidence must be repeatable by different scientists in different locations using different methods. This ensures the results are not due to chance or errors in a single experiment.

* Mathematical models: Scientific laws often have mathematical models that describe the relationship between different variables. These models can be used to make predictions and test the validity of the law.

* Lack of counterexamples: While a single counterexample can disprove a scientific law, it's important to note that a lack of counterexamples, despite rigorous testing, strengthens the law's validity.

Important Note: Scientific laws are not absolute truths. They are based on the current understanding of the universe and are subject to change as new evidence emerges.

Here's a key distinction:

* Scientific laws: Describe how the natural world behaves under certain conditions. They are generally considered universal and unchanging.

* Scientific theories: Explain why the natural world behaves the way it does. They are based on a body of evidence and can be modified or replaced as new evidence emerges.

In summary, scientific laws are backed by a robust foundation of evidence, repeated experiments, mathematical models, and the absence of contradicting evidence. They represent the current state of our understanding of the universe, but are subject to refinement and change as our knowledge grows.