Baldwin Kyle A, Butler Samuel L, Hill Richard J A
School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK.
Department of Geological Sciences, University of Saskatchewan, Saskatoon Saskatchewan, S7N 5E2, Canada.
Sci Rep. 2015 Jan 7;5:7660. doi: 10.1038/srep07660.
Determining the shapes of a rotating liquid droplet bound by surface tension is an archetypal problem in the study of the equilibrium shapes of a spinning and charged droplet, a problem that unites models of the stability of the atomic nucleus with the shapes of astronomical-scale, gravitationally-bound masses. The shapes of highly deformed droplets and their stability must be calculated numerically. Although the accuracy of such models has increased with the use of progressively more sophisticated computational techniques and increases in computing power, direct experimental verification is still lacking. Here we present an experimental technique for making wax models of these shapes using diamagnetic levitation. The wax models resemble splash-form tektites, glassy stones formed from molten rock ejected from asteroid impacts. Many tektites have elongated or 'dumb-bell' shapes due to their rotation mid-flight before solidification, just as we observe here. Measurements of the dimensions of our wax 'artificial tektites' show good agreement with equilibrium shapes calculated by our numerical model, and with previous models. These wax models provide the first direct experimental validation for numerical models of the equilibrium shapes of spinning droplets, of importance to fundamental physics and also to studies of tektite formation.
确定受表面张力约束的旋转液滴的形状是研究旋转带电液滴平衡形状的一个典型问题，这个问题将原子核稳定性模型与天文尺度的引力束缚质量的形状联系在一起。高度变形液滴的形状及其稳定性必须通过数值计算来确定。尽管随着越来越复杂的计算技术的应用和计算能力的提高，此类模型的精度有所提升，但仍缺乏直接的实验验证。在此，我们展示一种利用抗磁悬浮制作这些形状蜡模型的实验技术。这些蜡模型类似溅落状的玻陨石，即由小行星撞击喷出的熔融岩石形成的玻璃质石块。许多玻陨石由于在固化前飞行过程中的旋转而具有拉长或“哑铃”形状，正如我们在此观察到的一样。对我们的蜡质“人造玻陨石”尺寸的测量结果与我们的数值模型以及先前模型计算出的平衡形状吻合良好。这些蜡模型为旋转液滴平衡形状的数值模型提供了首个直接实验验证，这对基础物理学以及玻陨石形成的研究都具有重要意义。
