A scientific law is a generalization based on observations of a phenomenon. It gives descriptions regarding an event that occurs repeatedly when certain conditions are met, but it does not explain why the event happens. At the time a law is made, no exceptions currently exist.
A scientific law can be in the form of a statement or a mathematical formula. It implies a causal relationship between the elements observed, and it always applies providing that the conditions are the same. Although scientific laws are universal and accepted by all scientists in a given field, they can still be questioned and challenged, which only contributes to furthering human knowledge.