Capillary action is the ability of a liquid to flow against gravity in narrow spaces. It occurs due to the combination of two opposing forces: cohesive forces, which cause the liquid to minimize the surface area and form a round shape, and adhesive forces, which cause the liquid to cling to the surface. Consider capillary tubes in two different beakers. If the adhesive force is stronger, the liquid forms a concave meniscus. If the latter is stronger, the meniscus is convex. This equation gives the relationship between the height of the liquid rise and various parameters. The rise in height is independent of the capillary's shape but is inversely proportional to the capillary radius and the liquid density. The rise or fall in a capillary tube also depends on the contact angle. The liquid rises if the contact angle is less than 90 degrees and falls if it is greater than 90 degrees. Capillary action is essential for transporting water and nutrients in plants and applies to many industrial processes, such as dyeing and chromatography.