Likelihood of origin of Paleolithic tools as viewed from their entropy

Lithic tools are physical objects whose surface can be characterised by the scars left on them by the removal of stone flakes. In a recent article [1], we quantified the information contained in Paleolithic stone tools about their manufacturing process using Shannon’s information theory [2], with the notions of amount of information and entropy. The approach permitted to asses the probability that such objects were made by our hominid ancestors, and also the amount of information they carry. Here, we dig deeper into the physico-mathematical aspects of the subject and show that the entropy of a lithic tool can be defined on a physical basis following Boltzmann’s arguments [3]. Thus, the entropy of a stone tool acquires a physical meaning that enlightens considerably their interest. We also extend our previous treatment by considering the effects of curvature of the lithic surface on the probability density of strokes imparted randomly on it, and by taking into account the fact that there can be many tools effectively similar to the one being investigating. Although the number of tools equivalent to a given one is exceedingly large, the probability of observing any of them is still much smaller than that of observing a similar but roughly battered stone. In this work, however, we have not dealt on the archaeological implications of this work, which will be considered elsewhere.