Among the monumental architecture built by the Tiwanaku, whose civilization thrived in what is now Bolivia between 500 and 950 A.D., was a staggering complex known as the Pumapunku. For centuries, this structure dazzled all those who came across it; the Inca repurposed it for their own rituals, and European colonizers marveled at its beauty. But looting over the past 500 years has left Pumapunku in fragments, and scholars have struggled to figure out what the Unesco World Heritage site actually looked like. Fortunately, as George Dvorsky reports for Gizmodo, UC Berkeley archaeologist Alexei Vranich has devised a way to put the remnants back together using Lego-like, 3-D-printed pieces.
Pumapunku, or “Gateway of the Puma,” was a temple complex consisting of plazas and ramps placed on a raised platform, Vranich writes in a paper published in the open access journal Heritage Science. The structure is surrounded by a number of other monumental ruins on the site of Tiwanaku, both the name of the ancient empire and its capital city. Attempts to restore the site in the mid-20th century were poorly executed—“the ruins … hold the distinction of being considered one of the worst reconstructed sites in the continent,” according to Vranich—and Pumapunku exists today as 150 scattered blocks, none of which are in their original place.
The surviving stones of Pumapunku are too big to move around. But Vranich saw an opportunity to tinker with replicated parts of the monumental building through 3-D printed technology. He and his team consulted the field notes of two 19th-century archaeologists, along with those of JP Protzen, an expert in pre-Hispanic architecture, who worked at the site in the 1990s. Based on these existing measurements of the height, width and length of the blocks at Tiwanaku, the researchers were able to model 17 slabs of foundational sandstone and 140 pieces of andesite rock that made up the superstructure on a computer. They 3-D printed the blocks at 4 percent of their actual size, and then began the painstaking process of fitting the pieces together.
“[T]he overall appearance of the collection was similar to that of a recently started puzzle or, as commented by nearly every visitor that chanced upon the collection, an elaborate Lego set,” Vranich writes in the paper. “This metaphor is appropriate especially since most people entertain themselves with a puzzle until they cross the boundary between a harmless distraction and a maddening obsession.”
It might seem as though it would have been easier to model the entire structure using software, but Vranich maintains that the hands-on work was actually less cumbersome.
“[T]he human brain continues to be more efficient than a computer when it comes to manipulating and visualizing irregular 3-D forms,” he says. “We attempted to capitalize on archaeologists’ learned ability to visualize and mentally rotate irregular objects in space by providing them with 3-D printed objects that they could physically manipulate.”
In addition to creating a model that may finally give experts a visual representation of Pumapunku, the team’s reconstruction offered several new insights into the building. Perhaps most intriguingly, the researchers discovered that gateways that now lie smashed around the site were once aligned to create a “mirror effect”: the largest framing a smaller, which, in turn, framed an even smaller one and so on. “It would create an effect as if you were looking into infinity in the confines of a single room,” Vranich tells Gizmodo’s Dvorsky. This architectural choice may in turn be linked to the Incan belief that Pumapunku was the birthplace of the world.
Vranich believes his approach to reconstructing Pumapunku could be used to recreate other heritage structures that are falling apart, whether due to the ravages of time or more recent human influences, like the Islamic State’s destruction of ancient architecture in Palmyra. The researchers will also make their ready-to-print models available in an online archive, so other experts can at long last get a closer look at Pumapunku.