täthet

tæthet is a noun used in Nordic languages to denote the state or quality of being dense or close. In everyday usage it is translated as density, closeness, or compactness. In technical contexts, tæthet describes how much matter, or how many individuals, occupy a given space. Physical or material density is measured as mass per unit volume, in units such as kilograms per cubic meter (kg/m^3) or grams per cubic centimeter (g/cm^3). Population density describes how many people live in a defined area, typically expressed as people per square kilometer or per square mile. Occupancy density, such as people per square meter, is used in architecture and safety planning.

The word is derived from Nordic roots meaning tight or close, with a suffix that forms an abstract noun. Cognate terms include Swedish täthet and Norwegian tetthet, and Danish tæthed, all conveying the idea of density or closeness.

Applications of tæthet span science and planning. In physics and chemistry it describes material density and related properties; in urban planning it informs housing density, land use, and infrastructure needs; in ecology it helps quantify how crowded a habitat is; and in safety engineering it relates to crowding and egress. Density metrics are scale- and context-dependent; high density can imply efficiency or risk depending on distribution, porosity, and amenities, so care is needed when interpreting results.

See also density, crowding, porosity, and spatial analysis.