The mysterious Mehrgarh amulet from 6000 years ago
The mysterious amulet from 6,000 years ago found in a tomb in the archaeological site of Mehrgarh, in Pakistan, has begun to 'speak': 'interrogated' it revealed step by step the method used to its manufacture, which was found to be extremely sophisticated for its time.
“The past is the key to the present.” This scientific maxim generally means that the laws of nature in the ancient world still operate exactly today. The same goes for technologies, and a 6,000-year-old amulet that looks like a rusty provides a rather curious story that spans millennia.
Discovered by archaeologists in Mehrgarh (Pakistan), the amulet was handed over to a team of physicists who decided to take a closer look at the corrosion covering the sickly green surface. They noted that it emits various frequencies of electromagnetic radiation due to a oxidation of copper.
Luminescence analysis revealed that the amulet would have been born as a single piece of copper. The molten metal would be poured into a clay mold created around a wax model in the shape of the amulet. The amulet would therefore be one of the oldest metal objects ever made with the lost wax casting technique.
The deformed nature of the amulet, and these strange, unique spikes, suggest that the method used to make the amulet was a process known as lost wax casting, a true revolution in ancient metallurgy.
The step forward
Fast forward six millennia, and we have NASA, one of the most high-tech astronautics and astronomy organizations on the planet. And it's easy to understand that in the 58 years since it was founded, the pace of technological innovation has been extraordinary.
It is important to remember, however, that the abundance of their science and technology is based on many old principles and methods. After all, Newton's equations describing the force of gravity and, while less accurate than Einstein's, are still in use today.
As you have already guessed, the lost wax casting technique is also still in use by NASA. A variant of it known as investment casting is used to produce equipment that can withstand the harsh conditions of outer space.
Some of it is on board the International Space Station, and some parts are in the Curiosity rover on Mars. So we only have to learn from the past, even the distant one. A thread of science, which goes from the past to the present and will undoubtedly go into the future.
