The other dimensions have to be the spirit realm. The half-time dimension we live in--we can only go forward in time and not back in time---is open to the higher dimensions. I do not believe the fallen angels or demons can go back in time either which means there is a higher dimension than the angelic realm. Now we all know who can see the end from the beginning which is the highest dimension and according to the Bible, that dimension is offered to those that believe in Jesus as our Lord, King and Savior! Amen