I read recently that photons are largely responsible for why matter doesn't collapse in on itself!? For example, the electrons (negatively charged) and protons (positively charged) inside each of the atoms that make up our bodies should ordinarily attract each other and thereby cause us to collapse in a heap(?), however, because photons interact between electrons and protons this interaction suffices to keep the two apart. Does that sound about right? Related to the last point above... are there still photons in the air when it is pitch black?