After washing the evening dishes, the kitchen sink sits full of soapy water, nearly to the rim. Bubbles float on the surface, and bits of food swirl around.
Pull the plug, and water immediately rushes toward the drain hole in the bottom. The level drops steadily at first, with a strong gurgling sound filling the room. The sink lightens noticeably within moments.
Early on, the draining moves right along. The sink might lose half its water in a couple of minutes, leaving just a shallow layer.
As the water gets lower, the pace shifts. The flow turns into a thin stream, circling slowly around the drain. The gurgle quiets to a drip.
The final bits cling to the sink bottom, taking several more minutes to vanish completely. What began as a swift empty stretches into a slower process.
The water height above the drain drops gradually over time. Higher levels send water out briskly; lower levels let it linger. The draining situation drifts from rapid to drawn-out, all within the same sink.