On Explaining Existence 3 Why Questions

What are the limits of physics’ explanatory power? Can physics explain everything? In this paper I discuss a somewhat broader question: can physics explain existence itself? I argue that genuinely ultimate explanations—those that really explain everything—involve the most basic and most general elements of logic. Such explanations cannot be done within physics unless physics undergoes a methodology shift more closely aligning itself with mathematics and logic. However, I give reasons for thinking that just such a shift might be in operation. Even a solipsist agrees there is at least one thing! Roy Sorensen 1 WHAT PHYSICS CAN AND CAN’T DO Physics is very good at providing explanations for physical phenomena. If we are puzzled, for example, by the appearance of a rainbow, then, with our physics hats on, we seek to provide an explanation of it, such that the phenomenon (or, rather, some representation of it) is derived as the conclusion of an argument involving some physical laws and some initial/boundary conditions. Understanding comes as a natural consequences of explanation too: if the rainbow had to be, given the laws and the conditions, then we can claim to have understood the phenomenon of the rainbow. We can, of course, also make predictions and exert some control over the natural world along these same lines. However, what if the phenomenon we are puzzled about is the Universe as a whole (be it an ensemble or a unique instance) and the problem of where it came from? Cosmology and cosmogenesis were, until relatively recently, thought to be outside the ‘proper’ domain of science, to be relegated instead to the armchair speculations of metaphysicians and theologians. Of course, theory and observation have advanced to the stage where we might expect scientific explanations (and so understanding) of these deep questions too. We have theories of the structure and origins of the universe that submit themselves to elements of the standard scientific method. But now what if we are puzzled about existence itself? Never mind explaining why the universe has the contents it has, distributed as they are, with their properties ‘just so’, and so on. Why is there anything at all? This is really the ultimate question: why is there something when, presumably, there might not have been? There are two ways to go about answering this kind of question: 1. Show that existence is in fact necessary, so that there couldn’t possibly have been nothing—in other words, we deny that there might have been nothing, so that the presumption above is seen to be mistaken.