A vortex in a deep trough whirls water: centrifugal forces accelerate inner rings much faster than outer ones, making the trough look like a spiral that gets sucked into the center. The surface shape is calculated as a power function of radius — depth rises sharply near the axis, creating a characteristic 'pit'. Particles accelerate according to a law similar to conservation of angular momentum: the closer to the center, the faster they spin and the stronger they are pulled down. Foam clings to the surface and slowly drifts inward until it falls back to the outer edge. A point light in the center pulses, highlighting turbulence at the throat of the vortex.