In a gravitational field, the pressure in a fluid increases with depth. You can consider it due to the weight of the fluid above. Outside of scuba diving or hiking at altitude, this effect is not one typically given much thought. But what effect can it have at a smaller scale? This video shows the collapse and rebound of three initially spherical cavitation bubbles inside a liquid. Each bubble is created in a different gravitational field – one in microgravity, one in normal gravity, and one at 1.8x Earth gravity. The bubble in microgravity remains axisymmetric and spherical, but the two bubbles recorded in gravitational fields develop jets during rebound. Even at a scale of only a few millimeters, gravity causes an imbalance in pressure across the bubble that creates asymmetry. (Video credit: D. Obreschkow et al.)
Celebrating the physics of all that flows