A matter of light.

Still working as the world’s largest unreinforced concrete dome, the Pantheon circular interior or rotunda is covered by a huge coffered concrete structure with a central opening (oculus) to the sky. The geometry of the dome is completely spherical, being its diameter the same measure as its height (43,2m). The walls of the dome have a honeycomb geometry known as coffering which allowed for it to appear larger than it actually is. 

 

The Pantheon is still seen nowadays as a building clouded in mystery. The primary purpose of the construction remains practically unknown but it is obvious that the scale and size of it emphasizes power and Roman duty. There is a celestial symbolism present in the temple which is mainly represented by the oculus. This architectural representation could be linked in this case to the conquered and reaches of the roman empire, although history tells that the first intention of the construction was to honor all Greek Gods. 

 

The oculus is perceived as a circular opening left a the top of the dome with 8.8m in diameter and which structural purpose is to lighten the spherical construction at the tip of the top. The circular hollow is left opened to the outside climate conditions which somehow varies the atmosphere in the interior of the temple. Natural light is always introduced through this space, projecting its circular shape along the wall altering in position according to the time of the day. The angle of incidence of the sun rays makes also the projection change in shape and size, creating a big contrast between the illuminated circular form and the rest of the space, apparently left on the most complete darkness. 

 

Michelangelo, the greater painter of the sixtine chapel once described the design of the Pantheon as an “angelic and not human design”.(1)