MTheory 2010-04-07 19:08:19 2010-04-07 20:00:21 Definition a theory o f two dimensional 'strings' ='membranes' a theory of everything atheory o f twodimensional strings = membranes or branes \section{M-theory} is a relatively recent theory of everything, including the time evolution through the Big-Bang event that created our Universe. It replaces the older string theory in 10 dimensions with a \emph{brane} theory in 11 dimensions, one time dimension and 10 spatial dimensions. The Big-Bang is hypothesized to occur in M-theory as a result of the collision of two parallel universe branes, each with ten spatial dimensions and one temporal dimension. Heterogeneities in the new Universe formed after the collision would be explained by wave-like fluctuations of the two colliding branes. Moreover, a unification of five previous 10D string theories would occur in M-theory. Its equations may be then also unified with previous supergravity theory in 11 dimesnions.