This was made as an illustration for Dr A’s presentation at TAG (Theoretical Archaeology Group Conference) this year.
He only made up one of the explanations (guess which). Some of these theories come from outside the discipline of archaeology. But not all.
If you want to read more about carved stone balls, Dr A recommends Gavin MacGregor’s paper in World Archaeology, which is the basis for the ‘sculpture for the senses’ explanation.