Good question. There are lots of intellectual fields, e.g. in the social sciences, in which statements are rather fuzzy and imprecise, "laws' never are quite meant to be taken seriously, etc. In social science it's hard to see how that fuzziness could be avoided, but in physics it's not necessary. One of the drawbacks of laws that are easy to bend is that they can't ever be disproved. There's always some excuse for any discrepancy. Arguments tend to go on forever.
With our "strict" laws, we get a much sharper idea of whether they are working or not. It's precisely that strictness that allows us to say, for example, that Newton's law of gravity is not quite right. It's that same strictness that tells us that our current law of gravity, General Relativity, must break down on extremely short distance scales. People are working hard to replace it, maybe with a form of string theory. Meanwhile, more comprehensive pictures of the space-time manifold, in some sense including what are black holes from our perspective, are also being worked on.
Meanwhile, though, for events on a more familiar scale we have the strict laws of Special Relativity as an excellent well-controlled approximation. Combined with quantum mechanics, these allow the correct theoretical prediction of experimental quantities to extraordinary precision, e.g. one part in 100,000,000,000. When a theory like Special Relativity can do things like that, you don't just toss it out on a whim.
Mike W.
(published on 10/26/2010)
