Technology from Pakistan's Mehrgarh civilization used by NASA
Did you know that a 6,000-year-old amulet from Pakistan’s Mehrgarh civilisation is also the oldest example of a technology still used by NASA?
A group of scientists described how they used a powerful synchrotron beam to analyze the tiny amulet on a microscopic level, revealing the mystery of secrets that shrouded its origins.
Peering through the corrosion, they discovered that the true structure was not visible to the naked eye. They used the imaging technique called full-field photoluminescence to do so.
Modern science then revealed that there were countless tiny, bristle-like rods of copper oxide scattered throughout the interior of the amulet. Their structure was very different from the copper-oxygen compounds that pervade the rest of the object due to heavy corrosion over the millennia.
It is believed that ancient metallurgists were trying to craft the amulet out of pure copper but inadvertently allowed some oxygen in during the production process. Those early copper oxides hardened into the microscopic bristles in the amulet's interior.
Their existence, paired with the fact that the amulet is not symmetrical, also suggests that it was made via a process called lost-wax casting — one of the most important innovations in the history of metallurgy. The age-old process is still used to make delicate metal instruments today.
It involves crafting a model out of wax, covering it in clay, and baking the whole thing until the wax melts out and the clay forms a hard mould. After that, molten metal is then poured into this cavity and cooled until it hardens. When the mould is broken, a perfect metal model of the original wax structure remains.
This amulet is the oldest known example of this technique. Eventually, lost-wax casting would be used to produce countless functional objects — knives, water vessels, utensils, tools — as well as jewellery, religious figurines, and impressive metal statues of gods, kings and heroes.
The site of Mehrgarh was uncovered 35 years ago. Already known as a “crucible” of innovation amongst scholars, it is also the site at which the first evidence of proto-dentistry was uncovered. It lies west of the Indus River, on the Kacchi plains in Balochistan province, approximately 600 miles southwest of Islamabad.
Ancient evidence of agriculture, as well as the oldest ceramic figurines in South Asia, were also found at this Neolithic site. It is believed that this small community was a precursor to the entire Indus Valley civilization, one of the most important cultures in the ancient world.
Comentários