Islamic Artisans Constructed Exotic Nonrepeating Pattern 500 Years Before Mathematicians As early as the 15th century, elaborate symmetrical tile work on medieval Islamic buildings contained patterns straight out of modern math.

Medieval Islamic artisans seem to have developed a procedure for creating jigsawlike mosaics that ultimately led them to an exotic pattern that mathematicians would discover nearly half a millennium later. Researchers report that 15th-century buildings in Iran feature tiles arranged in a so-called quasicrystal, which is symmetric but does not repeat itself regularly.

“Here is evidence it [the pattern] was being used, if not understood, 500 years ahead of when we had any idea what was going on with [it] in the West,” says physics graduate student Peter J. Lu of Harvard University. Lu began poring over photos from Iran, Iraq, Turkey and Afghanistan after seeing hints of the pattern while traveling in Uzbekistan. The Islamic artisans seem to have spun a wide variety of symmetric traceries from a set of five shapes, according to a report Lu co-authored, published online February 22 in Science.