WHAT'S A BRANE ?

                                  WHAT'S A BRANE ?

  Mathematicians considering the existence of other uni- verses must entertain the possibility of more dimensions than the four we know as space-time: the three familiar dimensions plus the dimension of time, added by Einstein. In one version of string theory, physicists allow for eleven dimensions, including seven that remain imperceptibly "curled up." The visible universe could be a four dimensional membrane, or brane for short, moving through unseen dimensions. Other branes, or paralel  universes many also exist floating through a fifty dimension that we can not perceive Some scientists   propose that our would-be uninarse existed as  a brane into which another brane collided in a uniform fashion, generating the heat energy and expansion accounted for in the big bang. But these theories now exist mainly as mathematical models that require much additional investigation.