The notion of dispersion , coming from the Latin word dispersio , has several uses. The first meaning mentioned by the Royal Spanish Academy ( RAE ) in its dictionary refers to the act and consequence of dispersing : segmenting and spreading what was united, distributing attention, disorganizing.
In the field of mathematics , dispersion refers to how a series of values are statistically distributed . The dispersion focuses on the distance of the different values from the average value .
When the values are very far from the mean value, the dispersion is marked. On the contrary, if the values are close to the arithmetic mean, there is homogeneity .
This concept is specifically framed in the field of the branch of mathematics called statistics , which focuses on the study of variability, which is caused by paying attention to the laws of probability and from a random process. Also known as spread or variability measures.
More specifically, mathematical dispersion looks at the degree to which a distribution is squeezed or stretched, a concept in probability and statistics that consists of a function that gives events defined on a particular variable the probability of their taking place. Three well-known examples of dispersion are:
* the standard deviation , also known as typical , a measure used to put into numbers the variation of a set of numbers;
* variance : also called variance , a measure applied to a random variable to determine the expectation of its squared deviation in relation to its mean;
* the interquartile range : also called interquartile , the difference that can be observed in a distribution between the first and third quartiles (each of its parts, once divided into four).
According to physics , dispersion is the decomposition of radiation into its various wavelengths, produced by a propagation medium . The typical example of this phenomenon is light scattering .
White light is generated by the combination (superposition) of violet , indigo , blue , green , yellow , orange and red . When passing through a transparent medium and refracting, dispersion takes place and this light is decomposed into different colors.
Dispersion develops as light loses speed as it passes through the medium. With a lower speed of propagation, light is refracted in multiple ways.
The concept of dispersion also refers to the state of a gas or solid when, in its mass, it houses another body that is distributed uniformly. Fog , to mention one case, involves the dispersion of water in the atmosphere : small droplets remain floating in the air.
In the field of biology , on the other hand, we speak of dispersal to refer to the movement of plants, animals, bacteria, fungi and other individuals from the place where they were born to the place where they choose or correspond to reproduce or between two of reproduction. The first case is known as natal dispersal , while the second is reproductive .
It is also possible to understand this biological concept as the description of the movement of spores and seeds , among other propagules, a type of germ or part of an organism that is produced sexually or asexually so that a new one emerges, identical to the original.
Environmental pollution also uses this term, in particular to talk about the transport of a substance discharged by humans into the environment , whether it moves within an environmental compartment or is moved to a different one. Dispersion, in this case, occurs as a result of various biological, chemical and physical phenomena.