is there a way to automatically correct normal on a closed object? making all normal pointing outward or inward.or maybe pointing in the direction of the majority.
You can use CTRL+N to make all the normals point outwards, or if you want them going inwards, use CTRL+N and then press W and select ‘Flip Normals’ from the menu.
Or just CTRL+SHIFT+N for calculating inside 
Mystery