Sedimentation's the tendency for particles in suspension or molecules in solution to settle out of the fluid in which they're entrained, and come to rest against a wall. This's due to their motion through the fluid in response to the forces acting on them: these forces can be due to gravity, centrifugal acceleration or electromagnetism. Sedimentation may pertain to objects of various sizes, ranging from large rocks in flowing water to suspensions of dust and pollen particles to cellular suspen… (More on Sedimentation)