Density , from Latin dense, is the dense characteristic . East adjective , in turn, refers to something that has a lot of dough in comparison to his volume ; which is thick or solid; that has an important level of content or is very deep in a reduced dimension; or that is undefined and unclear.
In the field of chemistry and of the physical , the density is the magnitude which reflects the link that exists between the mass of a body and its volume At International system , the unit of density is the kilogram per cubic meter (known by the symbol kg / m3) .
A kilogram of bronze, for example, will occupy a much smaller space than a kilogram of feathers. This is explained by density: bronze is denser (has more mass in less volume) than feathers. The density differences they allow heavy but small objects and light but very large objects to exist.
Just as the relationship between mass and volume of a body allows to obtain the density of an object, the demography appeals to a similar logic to talk about the population density . In this case, the magnitude is calculated from the number of inhabitants that live in the same surface unit. If a city has 20,000 people distributed over a territory of 2 square kilometers, its population density will be 10,000 inhabitants per km2.
The optical density , on the other hand, refers to the level of absorption of luminosity. In photography, the concept of density is linked to the darkening of an image according to the amount of light to which it has been exposed.
In the computing , the density indicates the number of bits that can be deposited in a memory storage system.
Population density and environmental imbalances
A concept deeply linked to this concept is that of population density, which refers to the demography, that is, the number of individuals that live in a given territory.
So that all species, whether vegetable or animal, can develop in a certain habitat in a recommendable and equitable way with the environment, it is necessary that there be a couple relationship between resources present in the space and their use; if the number of individuals exceeds the amount of resources to be distributed among all, there is talk of a environmental imbalance, where life is in danger in all its aspects.
When this anomaly occurs, it usually happens that a series of changes in the populations are naturally carried out to avoid the excessive increase of the community and ensure the species survival. Some of these transformations are:
* Slow development (when space and food are scarce, individuals begin to develop slowly and therefore, reproductive processes are delayed, bringing balance to the community);
* Low fertility (Due to the weakening of mothers, because of poor feeding, the number of offspring decreases and are more prone to death);
* Decrease in the size of individuals (the shortage in turn causes individuals to grow and weigh less);
* Emigration (If possible, part of the population moves to other regions in search of a better quality of life);
* Disappearance of the population (When the damages caused in the natural environment are excessive, the extinction of the species in this territory can be generated. It can occur gradually or abruptly, as if it were an epidemic).
It should be mentioned that in the case of human beings, because the measures of birth control that exist and because, thanks to scientific advances the death rate It takes place at a more advanced age, we have come to overpopulate the planet. If exhaustive measures did not take place to equate the distribution of resources and at the same time control the level of births, it would be impossible not only end world hunger, but also ensure a prosperous life for the species in any corner of the planet.