Does Matter "Evaporate"? I'm wondering if Matter always exists since the big bang or if matter over time "evaporates". I'm not sure if "evaporate" is the right term, but I don't know of a better word. Basically I mean: It's transfered into energy, never to be matter again. Does that happen? And if so, does that mean that there was more matter in the universe in the past than there is now? Could the effects of more matter in the past explain why we think there is more matter in the universe than we can see?