# Cosmology of Dante Alighieri’s Divine Comedy a celestial revelation

## That’s Maths: Just as for music and maths, structure is the factor linking mathematics and poetry

If you think poetry and maths are poles apart, think again. About the sixth century, Indian poet and mathematician Virahanka codified the structure of Sanskrit poetry, formulating rules for the patterns of long and short syllables. In this process, a sequence emerged in which each term is the sum of the preceding two. This is precisely the sequence studied centuries later by Leonardo Bonacci of Pisa, which we now call the Fibonacci sequence.

Just as for music and maths, structure is the factor linking mathematics and poetry. One of the most fascinating examples of this interplay of ideas is Dante Alighieri’s Divina Commedia. The Divine Comedy is divided into three cantiche, evolving from the consequences of sin (Inferno) to the Christian life (Purgatorio) and the soul’s ascent to God (Paradiso). Each cantica comprises 33 cantos and an introductory canto brings the total number to 100.

The most amazing mathematical aspect of The Divine Comedy is Dante’s conception of the universe, what we might now call Dante’s cosmology

The cantos in The Divine Comedy average 142 lines, so the poem is about 14,200 lines in length. The lines are divided into tercets, or groups of three, each line having 11 syllables, so that the number of syllables in each tercet is 33, the same as the number of cantos in each cantica. The tercets have an intriguing rhyming pattern, aba, bcb, cdc, ded ... forming an interlocking chain in which each triplet is linked rhythmically to those immediately before and after it.

But the most amazing mathematical aspect of The Divine Comedy is Dante’s conception of the universe, what we might now call Dante’s cosmology. He imagines the material universe following the model of Aristotle, with nine spheres. The Earth is central, surrounded by spheres for the Moon, Sun, planets and fixed stars.