What scientific fields help the failure analyst understand the situations they investigate?
Physics is required in order to understand forces, stresses and workings of the analytical instrumentation we use. Chemistry is required in order to understand both corrosion processes and the effects of refining processes on the behavior of the materials we investigate. At least a limited grasp of biology is required to understand some types of corrosion. Geology and astronomy are required to understand the origin and source of the elements that populate the periodic table.
Science has evolved over the years through the formulation of hypotheses, which are then tested multiple times by multiple investigators. At some point, a consensus emerges among those working in the field for useful hypotheses. The now duly fact-supported theory gains a new level of acclaim when it is used to successfully predict new facts about the world. Some recent examples are the success of quantum physics in predicting and allowing observation of the Higgs boson. Another would be the success of Einstein’s word in allowing the observation of a gravity wave.
Scientific theories are thus inherently different from a personal theory in that they have been independently verified by multiple individuals and methods on the way to becoming a theory. It is generally impossible to document the development of personal theories in the same way so that multiple individuals may verify the accuracy.
It is important to understand the nature of a scientific theory. Despite the redundant verification underlying scientific theory, scientists make no claims of eternal, absolute truth. The very nature of science is that it always remains open to improved versions of its explanations of reality. Scientific theories are, at root, models of how the world works. There is not yet a universal theory of everything. All scientific theories are grounded within a particular discipline.