Confirming Einstein
Einstein's theory of general relativity has passed every test that it has ever been put to. However there are about 2 good reasons to think that the theory is incomplete and will eventually need to be overthrown in just the same way that Newton's was.
First of all, general relativity predicts its own fate, it breaks down in singularities, regions where the curvature of space-time becomes infinite and the field equations can no longer be applied.
Secondly, existing tests of general relativity have been restricted to weak gravitational fields (or moderate ones in the case of the binary pulsar). Major surprises in this regime would have been surprising, since Einstein's theory goes over to Newton's in the weak-field limit, and we know that Newtonian gravity works reasonably well.
First of all, general relativity predicts its own fate, it breaks down in singularities, regions where the curvature of space-time becomes infinite and the field equations can no longer be applied.
Secondly, existing tests of general relativity have been restricted to weak gravitational fields (or moderate ones in the case of the binary pulsar). Major surprises in this regime would have been surprising, since Einstein's theory goes over to Newton's in the weak-field limit, and we know that Newtonian gravity works reasonably well.