What determines whether a model,theory, or Law is valid?
A model is neither valid nor invalid; it is either good or bad. A good model is one that inspires theories which turn out to be valid. A bad model either inspires invalid theories or no theories. Big bang is a model, not a theory. It has inspired many invalid theories, resulting in many modifications of the model. A theory is a falsifiable hypothesis which can be tested by experiment and/or observation. The theory remains valid so long as its predictions are in agreement with all known experiments and observations, past and present. A single disagreement with experiment or observation falsifies the theory, making it invalid. A law is a theory in which the scientific community has a high degree of confidence. This usually means it has been tested under every circumstance which can be simulated in a laboratory, and correctly predicts observations from beyond the lab (such as astronomical measurements). Once a theory is declared law, it becomes the scientists’ security blanket; contrary o