问答题 Scientific research is intended to produce accurate explanations of how the natural world works and how it has become what it is now. However, increasingly, scientific research is undertaken with the explicit goal of accumulating knowledge. The knowledge built on science is always open to question and revision. No scientific idea is ever "once-and-for-all" proved. Ideas that we fully accept today may be rejected or modified in light of new evidence discovered tomorrow. Scientific explanations continually generate expectations that compel us to figure out how entities in the natural world interact and how we can harness that knowledge, providing scientists with incentives to conduct original research to verify the validity of a hypothesis.