wwwmind challenged me to be explicit about some theories of my own. Whilst my position of non-belief does not require that I hold any theories at all it would be disingenuous of me not to admit that I have some.  Many religions have developed from creation myths. Many of the conflicts between fundamentalist Christianity and science in the US seem to revolve around issues related to creation. The Creationist argument usually takes the form of: 'Science says that everything came spontaneously out of nothing, that's stupid god made everything out of nothing'. There is a conceptual problem for us in that we experience ourselves as part of a causal world and are drawn to seek causes for events. Existence itself is the most significant event, what is its cause?  Scientific method evolved by formalising the investigation of causal relationships. What non-scientists do not appreciate is that the quantum realm, where most of contemporary science leads, is not causal. The causal realm depends on conservation laws that do not allow something to come from nothing. In the quantum realm things 'appear out of nothing' all of the time; this is the nature of the quantum realm and scientists have had to live with it for nearly a hundred years.      There are different ways of thinking about nothing in the same way that there are different ways of thinking about infinity. If I have a dollar but I owe the bank a dollar my net assets are nothing and yet I have a dollar in my hand. Obviously the concept of a net 'nothing' such as this requires the existence of a bank and a financial system. The quantum realm provides a system like this. In some senses the quantum realm is a set of rules about possibility. Nothing 'exists' in the pure quantum ream there are just virtual interactions that may accumulate to impact on the causal realm. The quantum realm can generate particle and anti-particle pairs akin to having a dollar and owing a dollar - particles out of 'nothing'. It's even possible that one of these 'virtual dollars' can be invested and make a profit before it is paid back, thus making something permanent out of nothing (okay so it doesn't always work for the banks). The whole of what we experience as our causal reality can be thought of as being generated out of such interactions. Well all this is interesting but does not necessarily tell us anything about first causes, it merely gives us a model for the current causal/quantum ontology. However one can speculate that if there is (I choose my words carefully to avoid a linear conception) a point in spacetime where a universal singularity exists (usually referred to as the big bang, a mistake because it re-enforces the misconception of linear time) at this point the causal and the quantum would be indistinguishable.  Warning what follows is metaphysics! I can conceive of a concentration of 'nothing' that is in fact all possibility. In a process analogous to einselection only certain combinations of possibility are sustainable. Many combinations of physical laws are mutually incompatible and would lead to instantly unstable universes. Perhaps the set that we've got is the only set that is stable and emerged from a nothing of 'all possibility' of that singularity.    By this conception ultimate goal of science is to show that the physical laws are the way that they are because they could be no other.