[Reading Science] The Secret of Ancient Stone Spheres from 1.4 Million Years Ago

Israeli Research Team Uncovers Secret of Seokgu Production
Artificially Made Round
"Primitive Humans Also Appreciated Symmetry and Beauty"

Primitive humans, ancestors of ancient humans who lived about 1.4 million years ago, also knew 'art.' Analysis suggests that stone spheres (seokgu) found at various ancient habitation sites worldwide were not created by chance or accident but were crafted as artistic and decorative objects.

Stone tools discovered at the Ubeidiya site in northern Israel in the 1960s. Photo by the Royal Society Open Science

The Hebrew University Archaeological Institute in Jerusalem, Israel, published a paper with this content on the 5th (local time) in the academic journal Royal Society Open Science, published by the Royal Society of the United Kingdom.

According to the science journal Science, scientists worldwide were puzzled when about 600 small, round stones were excavated alongside stone tools such as hand axes at a site in northern Israel dating back approximately 1.4 million years. Although there were clear signs of modification, it was uncertain whether these were man-made objects, and their purpose was unclear. They were considered byproducts of stone tool production or tools used to make hand axes.

However, the research team concluded that ancient primitive humans intentionally created these round stones to enjoy 'symmetry' for artistic purposes. The team developed sophisticated 3D analysis software and scanned 150 stone spheres found at the Ubeidiya site in northern Israel, then analyzed them. Ubeidiya is known as a place where Homo erectus, ancestors of humans, lived about 1.5 million years ago.

The team precisely measured the angles of marks found on the surfaces of these stone spheres and tried to reproduce the methods ancient humans might have used. As a result, the team analyzed that these stone spheres were made through deliberate effort. For example, the main surfaces of each stone sphere showed clear traces of large flakes being removed first, followed by processing the newly exposed edges. Also, the surfaces where stones had broken off were rough, indicating they were not naturally formed. In natural conditions, worn and broken surfaces would be much smoother. Moreover, some stone spheres had perfect spherical shapes that could only have been made by someone.

The research team explained, "Primitive humans 1.4 million years ago seemed to have the ability to conceptualize round objects in their minds and shape stones accordingly," adding, "This would have required considerable preparation, prior consideration, refined craftsmanship, and skill." They also added, "Considering these stone spheres along with other artifacts, including elegantly made hand axes, it appears that primitive toolmakers could appreciate symmetry and beauty." However, the team has yet to determine the specific purpose for which ancient primitive humans made these stone spheres.