What are the strengths of scientific knowledge as a source of knowledge compared to other sources?

Ideally, scientific knowledge should be objective and available to anyone with the ability to observe carefully and think rationally. Scientific knowledge builds upon previous discoveries to more accurately describe the objective world. Scientific knowledge is not absolute or unchanging. When new knowledge or discoveries contradict previous science, it must be independently verified by many different researchers. If the new discovery withstands careful scrutiny, then it must be reconciled with previous science either by modifying it or overthrowing it completely. A good example modifying previous science is Einstein's general theory of relativity, which states that time and space are not absolutes, in contradiction with Newton's view of the Universe. We still teach and use Newtonian mechanics, however, because at very low velocities (relative to the speed of light) and weak gravitational fields, Newtonian principles give a good approximation. An example of overthrowing a previous theory is the ether theory of light propagation. Light waves were thought to propagate through an invisible ether, but Michelson and Morley showed that the speed of light is invariant relative to earth's orbit, demonstrating that no such ether exists.