Crashing drops make mini-Armageddon craters

周华

A raindrop hitting sand may not make the deep impact of an asteroid strike, but crash tests are showing that they leave behind a similar crater.

Xiang Cheng from the University of Minnesota in Minneapolis and colleagues released drops of water onto a bed of tiny glass beads, varying the impact energy to observe the resulting mini-Armageddon.

The team was surprised to find that craters formed by liquids have the same shape as an asteroid strike. Their shape also varies with the strength of impact in the same way.

The real value of these results is how they help us understand splashing liquids – which are more of a mystery than collisions between solid objects. They could help us predict the effect of rain on soil erosion or design better drip irrigation systems.

Journal reference: PNAS, DOI: 10.1073/pnas.1419271112

原文链接：Crashing drops make mini-Armageddon craters

周华

这篇报道转自《新科学家》网站。报道中提到的研究内容是用液滴撞击含水的沙地模拟陨石撞击地面产生的效果。从研究所用的技术角度看，这项研究并没有使用多少高大上的技术，其关键是“用液滴撞击沙地模拟陨石撞击效果”使这项研究带上了跨界的色彩。与此相比，这项研究的另外一个含义，即研究“雨滴撞击土地导致水土流失”则浅白了许多。这项研究的负责人Xiang Cheng是北大毕业生，现在在明尼苏达大学担任助教授，主要研究方向是软物质、颗粒流等等，详细信息请见：https://www.cems.umn.edu/about/people/faculty.id21886.html

wilson732

有启发意义

周华

是的，我们平时报项目总是喜欢把研究所用的技术提的高高的，但是却经常忽视其中包含的科学价值。这个研究的启发性就在这里，关键是这个idea很漂亮，找出了雨滴掉落沙地与陨石撞击之间的关联性。此前还看到过一个研究，用水槽研究黑洞的视界问题，想想这二者之间似乎并不存在关联性，但是那个项目的负责人硬是从信息传递角度看到了关联性，提出一个跨界或者说跨学科的项目。