like I have an open ocean this is 1 meter square area. So, all kind of waves are there, I know that the energy of that must be constant. Either now I can think is all the waves are coming one side, but I can say the same energy spread are shared by waves from all directions; this is what I have done. First place I say that all the energy shared by all waves from 1 side, but now I say all the energies shared by always from all sides.