Computed tomography has long served as a vital window into the human body, allowing doctors to detect hidden damage in organs, bones, and vessels—often in ways no other method can. Now, the same life-saving technology is offering archaeologists a fresh view into the ancient world.
A new study from the Massachusetts Institute of Technology, published in PLOS One, shows how medical-grade CT scanning can illuminate blind spots in human history when applied to archaeological materials. For the first time, the technique has been used systematically to probe the origins of early metallurgy.
Around 5,000 years ago, communities in what is now Iran began extracting copper from ore, sparking a technological shift that helped usher in the Bronze Age. Soon, copper and bronze were shaping tools, weapons, and ornaments across continents. Yet the methods early metalworkers used have remained difficult to decode. Surviving artifacts are few, fragile, and usually held in museum collections where invasive tests are off-limits.
This challenge prompted researchers to turn to cutting-edge, non-destructive imaging. CT scanning proved especially revealing. Using high-resolution 3D scans, the team examined emblematic finds from Tepe Hissar in Iran, uncovering structural details that had never been documented.
The focus of the study was slag—material left over from smelting—dating from 3100 to 2900 BCE. Locked inside this by-product are microscopic droplets, minerals, and chemical traces that act as snapshots of the smelting process itself.
CT imaging exposed intact copper droplets and tiny voids formed by trapped gas bubbles, offering clues about temperatures and techniques used by some of humanity’s earliest metalworkers.
The researchers collaborated with an industrial lab in Massachusetts to obtain scans fine-grained enough to reconstruct these hidden features. Their results mark a breakthrough for archaeometallurgy and promise new ways to investigate the workshops that fueled early human civilization.
