Incredibly small vibrating threads of energy, matter, like the strings of the Universe. Permeating absolutely everything around. In our dimension, as well as in others that are not visible. With their Universes. What is their number, infinite or not, the answer is not yet found. Beautiful and elegant theory, a whole trend. Although with the phenomenal problems that may yet be solved, where the main key is gravity. And just recently, it was hard for us to even imagine today's world of familiar things. And there was no big bang. Creation has always been. A single theory of everything.