Strings live in 9+1 world, M, 10+1 one line of criticism is string theory is unable to account for the number of large and compactified dimensions, i.e 1 (line) large, 9 curled, 2 large (sheet), 7 curled, 3 large 6 curled (our world) all the way to 9 flat or 9 curled. Is there an a priori reason that the degrees of freedom, dimensions, are spatial and not temporal? For example, why not 3 large dimensions and 6 time dimesions, or 3 large dimesions, 2 extended large brane worlds, 2 compactified dimensions, and 2 time dimensions? Since the world we live in is fixed at 3 large dimensions, whose to say the higher dimensions aren't time dimensions? Are additional time dimensions part of the landscape? i.e 9 spatial and 2 time dimensions? Is there an apriori reason string/m disallows multiple time dimensions?