My current understanding of string theory includes the idea that empty space (the 3rd dimension) is made of energy strings, just like matter. Not sure whether or not this is correct, however. Does it follow, then, that time (the 4th dimension) would be composed of energy? It makes sense to me that it would. Just curious to hear others' oppinions. EDIT: sorry for double post. I'm currently on an iPhone so the Internet is janky. Use other post please.