Fig. 1: This schlieren image shows the impact of a 20-mm-diameter, flat-bottom cylinder on a pool of water as it falls downward with a velocity of ~ 9 m/s.

The impact creates intense compression and tension waves, the gradients of which are shown by the bright and dark striations, that cause the water to cavitate within ~100 μs of initial contact. The red coloring is from the laser lighting.