If one reads a recent article on the new scientist, he or she will see that science (or the understanding of its topics) constantly change. The understanding which we draw from the world can be seen as a visual analogy to representing some unknown truth.
Scientists work in the field like blind-folded men trying to describe the attributes of an unknown physical object by feeling it out with their hands. But in the “field”, microscopes and other measuring instruments represent their hands. The article is littered with phrases like “must be constantly on our toes” and “sands of science are continually shifting”, which encourage scientists (and people who follow science) should always be open to updating their information about particular topics.
I think the key thing to understand is that just because ideas have been researched and set in some book (physical or virtual), doesn’t mean they will always be the correct ideas (or even that they’re the best ideas). One must check which scientific procedures lead to the best results and then choose those procedures over their competitors.