In M-theory, the fundamental constituents of the universe are membranes, or p-brane where p is the dimensionality of the membrane. Thus the strings theorized in [[String theory]] belongs in the class of 1 dimensional membranes, the 1-branes. | In M-theory, the fundamental constituents of the universe are membranes, or p-brane where p is the dimensionality of the membrane. Thus the strings theorized in [[String theory]] belongs in the class of 1 dimensional membranes, the 1-branes. |