In a cave, mineral-rich water drips from the ceiling, spreading ions used to construct stalagmites. A latest examine considers how the depth of a pool impacts the droplet’s splash and the way materials from the droplet spreads. The authors discovered a number of situations that change broadly relying on pool depth.

A drop falling right into a shallow pool had a splash that rapidly broke up into droplets (above). By dyeing the pool inexperienced and the droplet purple, they might monitor the place the droplet’s materials wound up. The spray of small droplets carried fluid far, however the principle level of affect had a robust focus of the drop’s fluid.

In distinction, a deeper pool despatched up a thick-walled splash crown that collapsed in on itself. This droplet’s materials noticed numerous mixing with the pool, however solely close to the purpose of affect. From their work, the authors concluded that fashions of stalagmite progress ought to incorporate pool depth with a purpose to seize how minerals truly focus and transfer. (Picture credit score: cave – H. Roberson, others – J. Parmentier et al.; analysis credit score: J. Parmentier et al.; through APS Physics; submitted by Kam-Yung Soh)