  The language and methods of algebraic topology, particularly homotopy theory,
have been extensively used in the study of the identification, the
classification and the evolution of defects. Topological methods provide the
means for the detection of gross features, such as holes in a manifold, and
therefore one would clearly anticipate that the defects, if identifiable by
such means, to be linked with that kind of configurations. In physical media,
however, defects usually manifest themselves in ways which have no distinct and
direct association with patterns of topological value along the lines of our
previous reference. In this paper we will postulate that the defects do not
themselves correspond to topological features. Instead, they are forced to
exist in order to redress the violation of physical rules happening as a result
of the topological nature of our system. We will, thus, assume that the
topology of our system changes with the introduction of defects. Therefore, the
relevent to our study topological methods will be applied to a well defined
physical system only in the absence of defects.
