Interacting superstring theories are best thought of as configurations of an NUMBER@1 dimensional supergravity theory called MISC@1 where one or more of the dimensions are curled up so that the line-extended charged black holes become long and light .

Different superstring theories with different numbers of dimensions are best thought of as versions of an NUMBER@1 dimensional supergravity theory called M-theory , where the extra dimensions are curled up , which means the strings become long and light .
