Density, from Latin densĭtas, is the characteristic of denso. East adjective, in turn, refers to something that has a large amount of dough compared to his volume; which is dense or solid; that has a significant level of content or is very deep in a reduced dimension; or that it is undefined and unclear.

In the field of chemistry and of the physical, the density is the magnitude that reflects the link that exists between the mass of a body and its volume. In the International system, the unit of density is the kilogram per cubic meter (known by the symbol kg / m3).

One kilogram of bronze, for example, will take up much less space than one kilogram of feathers. This is explained from the density: bronze is denser (it has more mass in less volume) than feathers. The density differences they allow for heavy but small objects and light but very large objects.

Just as the relationship between mass and volume of a body allows obtaining the density of an object, the demography appeals to a similar logic to speak of the population density. In this case, the magnitude is calculated from the number of inhabitants living in the same surface unit. If a city has 20,000 people spread over a territory of 2 square kilometers, its population density will be 10,000 inhabitants per km2.

The optical density, for its part, refers to the level of light absorption. 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 bytes 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 to say to the quantity of individuals that inhabit a determined territory.

So that all species, whether plant or animal, can develop in a certain habitat In a manner that is recommendable and equitable with the environment, it is necessary that there be an even 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, we speak of a environmental imbalance, where life is in danger in all its aspects.

When this anomaly occurs, it usually happens that naturally a series of changes are carried out in the populations to avoid the excessive increase of the community and ensure the species survival. Some of these transformations are:

* Slow development (As 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 the mothers, due to poor feeding, the number of young decreases and they are more prone to mortality);

* Decreased size of individuals (Scarcity 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 damage caused to the natural environment is excessive, the extinction of the species can be generated in said territory. It can occur gradually or abruptly, as if it were an epidemic).

It is worth mentioning that in the case of human beings, due to the fact that there are very few measures of birth control that exist since, thanks to scientific advances, the death rate takes place at an older age, we have come to overpopulate the planet. If comprehensive measures were not in place to equalize 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.