It has long been understood that elaborate explanations can always be contrived in order to explain observations. But why should we believe they are true? The backward motion of planets can be explained by a series of epicycles, designed specifically to fit the peculiar motion. But with heliocentrism no such adjustments are required—the backward planetary motion is a natural outcome. So while complicated narratives are needed for bed-time stories and soap operas, parsimony is valued in science. Nature, and only nature, should be explained. Scientists become suspicious when a theory becomes increasingly complex to accommodate failed expectations—when particular explanations are needed to adjust to contradictory findings. Read more