M理論一些問題

Are you asking for the super string theory?
Do you know what is the Great unified theory?
At the beginning of our universe, all of the 4 forces, gravitational, electromagnetic, strong and weak force are all combined in one. After the inflation, these 4 forces are seperated and become the form we kwon today. Many scientist what to unifined all these 4 forces to investigate the early stage of universe. They have found a way to unifined 3 forces, except the gravitation force.
Tthe super string theory can make a solution of the unifining of the 4 forces. Super string theory stated that all of our basic particles, eg leptons and quarks, and the forces transmitting particles, eg photons and gravitrons, are the present of a very very little string, it maybe open end or in a closed loop, that is the properties of the particles. By the use of super string theory, there is a solution of the unifining of the 4 forces, but only in a 11D and 20D space. There is a suggestion that our world is a 11D world, while except the 3 + 1D (x,y,z and t) are normal, the other 8D are fold in the size of planck scale (that is, very small, compare to the sizes of quarks and all other basic particles).
If ypu are interested in it, you can try to find on web by key word, super string theory, grand / great unifined theory.