If it disagrees with experiment, it's wrong.
The criterion of the scientific status of a theory is its falsifiability, or refutability, or testability.
There never comes a point where a theory can be said to be true. The most that one can claim for any theory is that it has shared the successes of all its rivals and that it has passed at least one test which they have failed.
A system is empirical or scientific only if it is capable of being tested by experience. These considerations suggest that not the verifiability but the falsifiability of a system is to be taken as a criterion of demarcation... It must be possible for an empirical or scientific system to be refuted by experience.
Again the message to experimentalists is: Be sensible but don't be impressed too much by negative arguments. If at all possible, try it and see what turns up. Theorists almost always dislike this sort of approach.
Every genuine test of a theory is an attempt to falsify it, or to refute it.
Where we have good, testable explanations, they then have to be tested, and we drop the ones that fail the tests.
If you're a physicist, for heaven's sake, and here is the experiment, and you have a theory, and the theory doesn't agree with the experiment, then you have to cut out the theory. You were wrong with the theory.
The ultimate arbiter of truth is experiment, not the comfort one derives from one's a priori beliefs, nor the beauty or elegance one ascribes to one's theoretical models.
Science should always be in the business of attempting to disprove itself.
The only relevant test of the validity of a hypothesis is comparison of prediction with experience.
There is no example of someone reading their scripture and saying, 'I have a prediction about the world that no one knows yet, because this gave me insight. Let's go test that prediction,' and have the prediction be correct.
It was not right to believe anything you couldn't see or hold in your hands or test with your teeth.
