Science is based on observations. Empirical relationships between observations are…

Science is based on observations. Empirical relationships between observations are called laws. For example, a graph of the position of an object vs. time is an expression of a law.
Theory is based on things you cannot measure; for example, one cannot measure momentum or energy, but only calculate them. If the imaginary things can be used to predict laws or observations you have a theory. If your theory cannot predict something that is observed …. or predicts something that is not observed . . . forget-about-it….. the theory not the observation! If your theory can not predict anything, the theory cannot be tested . . .why did you bother in the first place? Theories come and go. Scientists hide theories that do not work. … What does oxygen mean? . . . is oxygen really needed to make an acid? That theory has come and gone. Where did phlogiston go?
Do you believe in the Theory of Evolution? What can you predict right now from the Theory of Evolution? What new species will be discovered?