The interior and the dome easily gave visitors a visually imaginary sphere once inside the temple. The design of the dome was originally created based on the juncture of circles. Once inside the dome, there is a perfect sphere that is meant to be the orb of the earth. At the apex point of the dome, there is a circular opening that is referred to as the oculus and it shines light through the interior. The oculus was a big 30 feet diameter that allowed a lot of light in and symbolized the all-seeing eye of Jupiter. The only natural source of light was through the opening of the oculus and the entry door which set a wonderful mood in the temple. There was also the coffers that gleamed like stars from heave by having a series of that were covered in bronze rosettes. The interior was also decorated with marble veneer and sculptures, columns and much more breath taking aspects.
The Pantheon is a good example of Romans knowledge of geometry techniques and their use of the Greek tradition. Though the Pantheon was built for worship, it still stands to be very inspiring and will continue to be a great influence in the history of art and architecture of the Imperial age.
Resources: http://en.wikipedia.org/wiki/Pantheon,_Rome http://www.studymode.com/essays/Pantheon-100398.html