Department of Civil and Environmental Engineering, Lyle School of Engineering, Southern Methodist University, Dallas, TX, 75205, USA.
Department of Anthropology, University of Tulsa, Tulsa, OK, 74104, USA.
Sci Rep. 2020 Aug 6;10(1):13289. doi: 10.1038/s41598-020-70264-y.
Understanding prehistoric projectile weaponry performance is fundamental to unraveling past humans' survival and the evolution of technology. One important debate involves how deeply stone-tipped projectiles penetrate a target. Theoretically, all things being equal, projectiles with smaller tip cross-sectional geometries should penetrate deeper into a target than projectiles with larger tip cross-sectional geometries. Yet, previous experiments have both supported and questioned this theoretical premise. Here, under controlled conditions, we experimentally examine fourteen types of stone-tipped projectile each possessing a different cross-sectional geometry. Our results show that both tip cross-sectional area (TCSA) and tip cross-sectional perimeter (TCSP) exhibit a strong, significant inverse relationship with target penetration depth, although TCSP's relationship is stronger. We discuss why our experimental results support what is mathematically predicted while previous experiments have not. Our results are consistent with the hypothesis that when stone tip cross-sectional geometries become smaller over time in particular contexts, this evolution may be due to the selection of these attributes for increased penetration.
理解史前投射武器的性能对于揭示过去人类的生存和技术的进化至关重要。一个重要的争论涉及到石尖投射物穿透目标的深度。从理论上讲，在所有条件相同的情况下，尖端横截面积较小的投射物应该比尖端横截面积较大的投射物更深地穿透目标。然而，之前的实验都支持和质疑了这一理论前提。在这里，我们在受控条件下实验性地检查了十四种具有不同横截面几何形状的石尖投射物。我们的结果表明，尖端横截面积（TCSA）和尖端横截面积周长（TCSP）都与目标穿透深度呈强烈的、显著的反比关系，尽管 TCSP 的关系更强。我们讨论了为什么我们的实验结果支持数学预测的结果，而之前的实验却没有。我们的结果与这样一种假设一致，即当石尖的横截面几何形状在特定情况下随着时间的推移而变小，这种进化可能是由于选择了这些属性以增加穿透性。
