  Choosing the appropriate geometry in which to express the equations of
fundamental physics can have a determinant effect on the simplicity of those
equations and on the way they are perceived. The point of departure in this
paper is the geometry of 5-dimensional spacetime, where monogenic functions are
studied. Monogenic functions verify a very simple first order differential
equation and the paper demonstrates how they generate the line interval of
special relativity, as well as the Dirac equation of quantum mechanics.
Monogenic functions act as a unifying principle between those two areas of
physics, which is in itself very significant for the perception one has of
them. Another consequence is the possibility of studying the same phenomena in
Euclidean 4-dimensional space, providing a different point of view to physics,
from which one has an unusual and enriching perspective.
