connecting lines. Two spin networks would not join smoothly similar to the impossibility of covering a curved space by a patchwork of small, flat spaces. This is taken to mean that the overall space is curved, or to put it another way, the very fact of this failure to join is the curvature of space. In the limit, when the number of spinors becomes infinite; a continuous picture of space arise. Even though this is a provocative concept, but in the end it is not useful for the unification of quantum theory with geometry. The space created is incomplete, it is static and nonrelativistic, and it contains no sense of distance or of separation. However, the idea of spin network has now become a key concept in loop quantum theory.