Science, its scope and methodologies were outlined mostly in the 19th and 20th Centuries. There were certain assumptions about the nature of the universe and based on these, the manner in which things can be tested and understood were fixed.
It is becoming increasingly clear that these assumptions are no longer valid. So...obviously science (as defined in earlier times) is no longer equipped to even observe let alone infer and analyse all aspects of the universe. I again have to give the example of the microscope that is very useful to observe certain phenomena but is useless to observe certain other phenomena.
Falsifiability is one such factor.
(Refer the biocentrism thread)
It is more a question of paradigms, rather than the scope of science and its methodologies. The great eminence grise of former times was of course Isaac Newton, and most scientists thought his ideas were just about beyond challenging. This is beautifully illustrated in the research into the of the nature of our solar system, following on from the discovery of Uranus. Uranus' orbit seemed to show some idiosyncracies which prompted two possible main explanations: either there was some other planetary body perturbing the orbit of Uranus, or Newton's principles of gravitation might be wrong. Scientists were keen to seek out the first option, because of the horrific implications of the second alternative. They were proved right, and the planetary body discovered was called Neptune.
However, in the 19th century, a similar problem arose, concerning the orbit of Mercury. Again, there was a frantic search for another planetary body (they pre-named it Vulcan), knowing that the alternative to such an unknown mass closer to the sun would be to question the Newtonian explanation. In this case, however, it
was the Newtonian explanation that was wrong, as was eventually demonstrated by Einstein's ideas - and a large paradigm shift occurred.
This however has done nothing to shift the scope and methodologies of modern science - it has of course broadened our insights into reality though.