The solutions had a curious peculiarity: they depended on closed lines in space. A closed line is a “loop.” Smolin and Jacobson could write a solution to the Wheeler-DeWitt equation for every loop: for every line closed on itself. What did this mean? The first works of what will later become known as “loop quantum gravity” emerge from these discussions, as the meaning of these solutions of the Wheeler-DeWitt equation gradually clarify. Upon these solutions, little by little, a coherent theory begins to be erected, inheriting the name “loop theory,” from the first solutions studied.
