What’s The Connection Between Complex Chemistry and Islamic Medieval Architecture?

karbala, iraw

The glittering shrines and mosques that characterized medieval Islamic architecture are more than just a pretty sight. Other than the bright azure, scarlet, turquoise, green colors and the gold-leaf, it is the patterns that make the architecture stand out. Interlacing patterns are featured prominently in Islamic arts as a substitute for more figurative images. The reasoning was that images depicting people would lead to idol worship.

Islamic interlacing patterns can be divided into two categories: the arabesque versus girih. While arabesque designs feature more curved elements in an effort to emulate greenery and nature, the girih is composed of geometric lines mostly of stars and polygons with interlaced lines. Muslim architects designed this tiling system with only a compass and ruler. These patterns became complex tessellations with five shapes: bowtie shape, a rhombus, a pentagon, an elongated hexagon, and a decagon. Between the 1200s to 1400s, Islamic art developed the girih exhibiting the same complexity as quasi-crystals, a material that defies normal atom packing. The vibrant marble structures exhibit the same mathematics as revolutionary material science.

Quasi -crystals are made of patterns that look regular but do not repeat exactly. The patterns in Islamic Architecture demonstrate this by including “tessellations” that have five, ten, and twelve-fold symmetry. Technically, these would not be patterns, but they appear to be so. Scientists conjecture that Islamic architects wanted this effect to extend a pattern without just repeating images. The concept of quasi-aperiodic tiling crystals was discovered over 500 years later by mathematical physicist, Roger Penrose at University of Oxford. Quasicrystals are found mostly in metallic alloys such as (Al-Li-Cu), and lack translational symmetry.

The discovery of the non-symmetrical packing of atoms took a while for the scientific community to accept. Although first discovered in the 1960s, much of the scientific community refused to believe that materials could consist of irregular atomic structure. Next, materials scientist, Dan Shectman, designed an artificial alloy with quasi-crystal properties. He did not publish his results for years due to a fear that others would ridicule his work.  It was only after a natural quasi-crystal, icosahedrite, was found in the Koryak Mountains, Russia in 2009 that led people to be convinced. Dr. Shectman received the Nobel Prize in Chemistry in 2011 for this work.

The connection between Islamic girih and quasi-crystals occurred recently; Dr. Peter Lu from Harvard University recognized ten-fold symmetry in architectural motifs while visiting Uzbekistan.  He analyzed 3700 Penrose tiles found in an archive of documented medieval Islamic architecture, and published a paper with Princeton University’s Dr. Paul Steinhardt titled ”Decagonal and Quasi-Crystalline Tilings in Medieval Islamic Architecture”. He only found 11 imperfections in the tilings, which could easily be explained by a simple mistake from a worker.. Dr. Lu uses the Darb-I-Imam Shrine in Iran as the iconic “near perfect” example of Penrose tiling. He conjectures that laborers could easily have created mathematically complex patterns by lining tiles decorated with lines that, once set down next to each other, form a continuous pattern. The glorious, kaleidoscopic patterns of Islamic architecture were over 500 years of western mathematics. It is much more than a simple decorative technique.