Reverse engineering the Stone Age: secrets hidden in ancient tools

In our latest episode of Lexicon, we sat down with Paleolithic archaeologist Dr. Ariel “Arik” Malinsky-Buller from the Hebrew University to explore what ancient stone tools can reveal about engineering, travel, and survival tens of thousands of years ago. Focusing on the Ararat-1 Cave site in the Armenian Highlands, Arik explained how nearly 1,800 stone artifacts (including local chert and obsidian transported over considerable distances) reveal a surprisingly sophisticated technological system. Also, subscribe to IE+ for premium insights and exclusive content! Reverse engineering ancient technology Arik kicked things off by describing the work of a Paleolithic archaeologist as a form of reverse engineering. “We are trying to puzzle back, to do reverse engineering of the way that they were manufactured,” he said. Rather than looking only at the shape of a finished tool, the researchers attempted to reconstruct its entire life. That included where its material came from, how it was manufactured, how it was used, how often it was repaired, and when it was finally discarded. According to Arik, this process allowed archaeologists to identify “fragments of decision-making.” “We can actually pinpoint where they stopped, why they stopped, and what the logic was for why they were stopping,” he explained. Through the marks left on objects made 35,000, 45,000 or even 50,000 years ago, the team could begin reconstructing the thought processes behind them. “You can actually go back and reverse the way they did it and the logic behind it,” Arik said. “This is, in a sense, the marvellous thing about this work.” One of the most intriguing discoveries, he explained, involved tools that were no longer inside the cave. Archaeologists found tiny flakes produced when tools were repaired, but not always the tools themselves. Arik called them “ghost tools.” “We can see the retouch pieces, or the byproducts of them, but the tool itself is gone,” he explained. The people visiting Ararat-1 appeared to have carried valuable obsidian tools with them. When those tools became worn, they stopped at the cave, repaired them and continued their journey. “They came there, they rejuvenated, they resharpened, and they moved out,” Arik said. The tools had been maintained repeatedly, shrinking from blanks measuring perhaps six or eight centimetres to objects only around 2.5 centimetres long. Arik compared the process to repeatedly sharpening a pencil until only a tiny IKEA-style pencil remained. Ararat-1 therefore did not appear to have been a permanent settlement or major workshop. Evidence from fireplaces, animal remains, carnivores, and even owl pellets suggested that people occupied it only briefly. The cave had effectively served as a prehistoric rest and maintenance station. When sharper was not always better Obsidian looked like an obvious choice for a cutting tool. It was volcanic glass and could form an exceptionally sharp edge. Variations of it are still used for certain modern surgical blades. However, experiments carried out by Arik’s team produced a counterintuitive result. “Obsidian is not beneficial,” he said. “If you want to use obsidian, you need not to sharpen it. You need to blunt it,” he added. An untreated obsidian edge could be too sharp and brittle for some jobs. When used to work animal hide, for example, it could cut through the material instead of scraping or processing it properly. “Here, you resharpen to make it dull,” Arik explained. Chert, on the other hand, behaves differently. It was less spectacularly sharp, but far more durable. Experimental tools made from chert could repeat the same movement thousands of times without suffering the same kind of damage. “You think something that is sharp is better than something that is dull,” Arik said. “But sometimes it is working the other way around.” Ancient toolmakers therefore had to understand more than how to make a sharp edge. They had to choose the right material and edge geometry for a particular task. Butchering an animal, removing its skin and processing its meat could each require a different balance of sharpness, precision and durability. Arik described this as “a cascade of decision-making.” The contrast between chert and obsidian also revealed how these groups managed resources. Local chert could be collected near the cave, used for an immediate task, and thrown away. Obsidian was different. The nearest known source lay roughly 25 miles (40 km) away, while some pieces had travelled as far as 124 miles (200 km). That was not a simple walk across flat ground. The Armenian Highlands featured steep climbs, sudden ecological changes and volcanic sources located more than 2,000 or even 3,000 metres above sea level. Snow also made some sources inaccessible for part of the year. “Movement of 40 kilometres or 80 kilometres is very rare in the record,” Arik said. “Here, it is the norm.” The researchers could not prove whether individual people had collected the obsidian themselves or obtained it through some form of exchange. Either explanation, however, suggested extensive movement and contact between communities. “In any way, it means that people knew each other, or knew the neighbours, or the areas that they covered in their yearly movement were huge,” Arik added. Ancient cognitive maps Travelling across that landscape required much more than physical endurance. People needed to know where resources could be found, which routes crossed the mountains, and when those routes were safe to use. “You need to know where to go,” Arik said. “If you will not have the cognitive map of where to go and what to search, you have no clue.” That cognitive map had been built from knowledge accumulated across generations. It included geography, raw materials, water, food, weather, and seasonality. “The map includes where to go, when to go, and so on,” Arik explained. Toolmaking knowledge also had to be passed between people. The gestures required to shape a stone tool were precise and difficult to learn through guesswork alone. “You need to be very intimate with someone that teaches you how to do it,” he said. Despite the large distances separating the sites, researchers found remarkably similar toolmaking practices across the region. To Arik, that suggested relatively small populations that remained closely connected. “There were not a lot of people around, but they moved a lot,” he said. “They knew each other, and they knew how to do things in a very similar way.” Engineering survival from winter to winter According to Arik, conditions in prehistoric Armenia could be brutal. Winter temperatures fell to around minus 20 degrees Celsius, while snow could reach a metre deep. Yet the archaeological record suggested that these communities repeatedly survived and maintained their technological traditions. “The evidence in the stones shows some sort of consistent interaction that enabled them to mitigate the risk,” he said. Their survival depended not only on tools, but on movement, teaching and the collective preservation of knowledge. People had to know when to move to lower elevations, when to return to the mountains, and where vital resources would be available. “This teaching of those people was the trick that enabled them to survive from winter to winter,” Arik explained. As he explained, none of these conclusions came from stone tools alone. The project brought together archaeologists, geologists, dating specialists and experts studying sediments, animals and raw materials. “All these lines of evidence, all this detective story, came into one holistic picture,” Arik said. As Arik put it, archaeologists were “trying to squeeze blood out of the stones.” From some of the smallest surviving fragments, they were reconstructing how ancient people thought, travelled, engineered, and survived.