"Majorana thought that the notion of symmetry allows one to grasp what is permanent in the flow of phenomena...In the world of elementary particles, interesting symmetries operate within spaces that only mathematicians know how to represent and that are distinct from three-dimensional physical space. These symmetries are directly related to the dynamic properties of physical systems, i.e. the way they behave under the effect of a force. And it may prove very fruitful to begin by identifying the fundamental symmetries that govern phenomena because they are at the source of the invariant quantities or structures that are capable of revealing deep reality."