15:50 17 November 2016
A 6,000-year-old amulet has been shown to be the older known example of a metalwork technique still used by Nasa.
The ancient amulet, which was discovered in the Neolithic village of Mehragarh, Pakistan, is thought to be the earliest example of lost-wax casting, a technique used for duplicating metal objects.
In a bid to understand how it was made, the artifact was analysed using a technique known as “photoluminescence imaging”. The process involves shining a light on the artifact to measure the amount of light that bounces back, which helps researchers identify the exact materials used to create the amulet. They found that the amulet was made with pure copper melted in a clay mould using lost-wax casting, the same technique used to create numerous components of the International Space Station, the Curiosity Mars rover and parts of the Messenger spacecraft.
'It is also today the highest precision metal forming technique— under the name ‘investment casting’—in aerospace, aeronautics and biomedicine, for high-performance alloys from steel to titanium,' explain the researchers.