The 5th Dimension is perhaps one of the least known things in the universe. All that is truly known of it is that it is tapped into to allow them to have extraordinary powers and abilities.
What is most interesting is that all of the zodiac signs have an element associated with them that they can control. It is unknown why this is so but it is believed this is because it is intertwined with toms in that particular pattern.
Otherwise, not much is known of the 5th Dimension.