Density (disambiguation)
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Look up density in Wiktionary, the free dictionary. |
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Look up dense in Wiktionary, the free dictionary. |
Density and dense usually refer to a measure of how much of some entity is within a fixed amount of space. Types of density include:
In physics, density of mass:
- Density, mass per unit volume
- The Planck density, the derived unit of density in the Planck unit system (1 Planck mass divided by 1 Planck volume)
- Area density or surface density, mass over a (two-dimensional) area
- Linear density, mass over a (one-dimensional) line
- Bulk density, mass of many particles of a particulate solid or a powder divided by the total volume they occupy
- Particle density or true density, density of the particles that make up a particulate solid or a powder
- Relative density or specific gravity, a measure of density in comparison to the density of something else
- Vapour density, a relative density used for gases
In physics, densities of entities other than mass:
- Number density, number of particles per unit volume, area, or length
- Current density, the ratio of electric current to area
- Charge density, the electric charge per volume
- Energy density, potential energy per unit volume or mass, depending on context
- Force density, force per unit volume
- Optical density, or Neutral density, the absorbance of an element
In mathematics:
- Dense set and nowhere dense set in topology
- Dense-in-itself, in topology, is a set that contains no isolated points
- Schnirelmann density in number theory
- Natural density (also called asymptotic density) in number theory
- Lebesgue's density theorem in measure theory
- Probability density function, a function which maps probabilities across the real line and whose integral is 1
- Density estimation is the construction of an estimate of a probability density function
- Kernel density estimation, used in statistics to estimate a probability density function of a random variable
- Tensor density in differential geometry
- Density (graph theory), the fraction of possible edges that exist in a graph
- Dense order in order theory
- A coinitial subset in the mathematical theory of forcing
- Density (polytope) in geometry
- Density on a manifold
- Dense submodule in abstract algebra
In other scientific fields:
- Population density, population per unit area
- Memory storage density, bits (how computers store information) over an amount of area or volume
- Nutrient density, the proportion of any array of a single nutrient or nutritional factor, or of numerous nutrients in foods, often ordered by different scalar indices
- Urban density, in urban planning and urban design
Density can also refer to:
- Spiritual density, levels of spiritual evolution, planes of existence or "dimensions" in The Law of One
- Stupidity, a stupid person is sometimes referred to as being "dense"
In Arts:
- Dense (film), a 2004 film
- Density 21.5 – a piece of music for solo flute written by Edgard Varèse