So therefore, just to make it a guess omega e really will not tell the correct story because the same omega e would have arise in because of different physical phenomenon, different actually wave systems. So, this is a function of omega e, that is one part, but then one has to have simple solution methods because you cannot keep waiting for that. So, what has happen? People have been waiting working for that for a long time and I will mention a practical way of estimating that now, which is called synthesis based on strip theory. See what happens? You know Always a two dimensional, these are mathematical problems a two dimensional solution is simpler than a three dimensional solution.