European Cathedrals

The intricate decoration of Gothic, Renaissance, and Baroque architecture, especially as expressed in cathedrals, frequently exhibited scaling over several levels.
    On the left, the central window is an arch made of two arches, each of which is made of two still smaller arches. This construction a stone tracery of interlocked arches, was developed in Gothic architecture to strengthen windows agains the pressure of wind.
    In the middle note the spires surrounded by spires surrounded by spires.
    What fractal patterns can you find on the right?
Click each picture to enlarge in a new window.
Why is repetition across scales common in the architecture of these periods?
    Were the builders informed by the fractal aspects of Nature?
    Perhaps the hierarchical arrangement of features was meant to represent theological hierarchies.
    Or perhaps the fact that the pointed arch, developed in Gothic cathedrals, allowing the vault to be adapted to any area, put scale-invariance into the architects' minds.
This decoration from the Basilica di San Clemente may look familiar. Click for an enlargement in a new window.