Could you explain minkowski's 4 dimensional principle in more detail?
In mathematical physics, Minkowski space or Minkowski spacetime (named after the mathematician Hermann Minkowski) is the mathematical space setting in which Einstein's theory of special relativity is most conveniently formulated. In this setting the three ordinary dimensions of space are combined with a single dimension of time to form a four-dimensional manifold for representing a space-time.
In theoretical physics, Minkowski space is often contrasted with Euclidean space. While a Euclidean space has only space like dimensions, a Minkowski space also has one timelike dimension. Therefore the symmetry group of a Euclidean space is the Euclidean group and for a Minkowski space it is the Poincare.