Hi Below are three questions. I realise that they’re probably better described as three different ways to announce that I’m stupid, but I’m hoping there are answers. I have tried looking these things up, but I haven't really got anywhere, and am as confused as ever. I apologise for the length and incoherence of the questions, but I thought it might help if I tried to fully describe what’s bothering me. Many thanks in advance to anyone who takes the trouble to answer. 1. If I set fire to a stick, I create light. Where precisely does that light come from? I think I mean from what particle (or part of a particle) does the light begin? The application of heat to the stick causes something to happen to x, as a result of which x produces a photon, so what is x? And what was the photon before it become a photon (i.e. before the heat was applied)? Basically (I think), where do photons come from or how are photons made? 2. The universe is expanding. At what velocity is it expanding? Can there be said to be an outer edge of space-time (like the shockwave of an explosion)? What exactly is it that is expanding – is there actual stuff which is going somewhere new, and if so, what is that stuff? And if there’s a finite amount of stuff in the universe, is the stuff that’s going somewhere new leaving gaps behind it, or are things becoming increasingly thinly spread? 3. Am I made of space-time, or do I exist within it? I mean, is everything that is me (or you, or a pencil, or a star) a separate entity, or a particular configuration of space-time, rather like a condensation of stuff in a bigger pool of the same stuff (stuff being, I suppose, space-time)? I think this question might simply be this: are objects (or matter) merely collections/points of density in a big pool of space-time?