Infinite Limits

Emblem of Lightness

        At any depth in a fluid there is an upward force due to the effect of gravity on the fluid. This results in a pressure applied over an area. If the density of an object in the fluid is greater than the density of the fluid, the object will sink. If the density is less than that of the fluid, the object will float upward due to the buoyancy from the fluid. An object of lower density will float to the top and only be submerged by an amount according to the ratio of the densities. Since the density of wood is less than that of water, the wood will float due to the buoyancy from the water. Buoyancy is what makes a piece of wood float in water.

        In imitation of Calvino’s emblem on lightness, how wood floats on water represents a simple symbol that sums up this memo. Since a unit volume of wood has less mass and weight than the same unit volume of water, objects sink into the water until they take the place of a volume of water equal to their own weight. If the entire object displaces a volume of water which weighs less than the object (a stone or a lead weight, for example) the object will sink. Wood is made of dead plant cells and contains many open spaces. This is why it is so relatively light when it is dry. Wood that is wet will float but not as high as wood that is dry would. This is because the spaces in the wood are filled with water and the wood is heavier or more dense. Even so, the material of which the cells are made is still lighter than water and so wood floats even when wet.

      Since Calvino mentions that there is an opposition between lightness and weight, wood is a good example of such. Wood floating on water exemplifies lightness compared to weight since the mass of the wood determines if it will float on water.