It is called equilibrium to the state in which a body is found when the forces acting on it compensate and cancel each other out. When a body is in static equilibrium, if it is kept that way, without any type of modification, it will not undergo translational or rotational acceleration, while if it moves slightly, three things can happen: the object returns to its position original position (stable equilibrium), the object deviates even further from its original position (unstable equilibrium) or remains in its new position (indifferent or neutral equilibrium).
Meanwhile, although the term is widely used in different areas, such as physics, biology and economics, in all of these it will always refer to something that is maintained in a fair measure despite incidents or contingencies.
In the field of physics and engineering we find three types of equilibria, the thermodynamic which refers to the situation of a physical system in which its external factors and internal processes do not produce changes in temperature or pressure. The chemical occurs when a chemical transformation reaction occurs at the same time as its inverse and then there are no changes in the compounds. And finally, the mechanic, is when the sum of the forces on all the parts is canceled.
In relation to thermodynamics, for example, within the kinetic energy or energy of movement, the forms of heat transfers, in general, seek thermal equilibrium either through conduction (transfer by contact), convection (transfer by wave displacement ), or radiation (radiation transfer of waves). Thus, for example, in the case of convection, when we turn on an air conditioner, the displacement of the heat waves will tend to balance the temperature of the environment that is within reach of the device, depending on what graduation we have chosen. Or, for example, a coin exposed to the action of the sun's rays will undergo changes in its temperature, also as an action of thermal equilibrium, between the origin temperature and degrees of exposure to heat.
On the other hand, the equilibrium for biology is closely related to the theory of evolution of the species, since it maintains that the specification of a determined being, normally, occurs after a time of stability and absence of changes.
One type of balance popularized in recent years is the environmental balance, within the concerns of many civil organizations and state agencies due to the current environmental emergency. This balance between human action / environmental impact aims to minimize the consequences of damage to the environment, for which man has been unconcerned for centuries. Industrial activity and the exploitation of natural resources are two areas of economic production that must be subjected to these principles of environmental balance. The concept of sustainable development comes hand in hand with this trend of human evolution.
Equilibrium also occupies a prominent place within economic science as well, then, it is said that an economic situation is balanced when supply and demand are equal or the plausible factors of causing changes offset each other giving stability. Something that, for example, is not happening in the current world economy as we all already know.
And finally, for physical education, the balance or sense of balanceIt is one of the most precious skills to achieve, because mastering this sense is what will allow athletes who are performing some acrobatics, not to collapse on the floor and hit each other.
Even within circus activity, balance plays a fundamental role, and there are "experts" in tests of this type, who are called "tightrope walkers". They usually walk on narrow ropes between different points, for which body control and balance must be extreme.