We explain what entropy is, what negative entropy consists of and some examples of this degree of equilibrium of a system.
What is entropy?
Inphysical we speak of entropy (usually symbolized with the letter S) to refer to the degree of equilibrium of a thermodynamic system, or rather, to its level of tendency to disorder (entropy variation). When a positive entropy change occurs, the components of a system go into a state of greater disorder than when a negative entropy occurs.
Entropy is a key concept for the Second Law of Thermodynamics, which states that “the amount of entropy in the universe tends to increase in the weather”. Or what is the same: given a sufficient period of time, systems will tend to disorder. This potential for disorder will be greater the closer the system is to equilibrium. The higher the equilibrium, the higher the entropy.
It can also be said that entropy is the calculation of the internal energy of a system that is not useful for doing work, but exists and accumulates in a given system. That is, theEnergy surplus, disposable.
When a system passes from an initial state to a secondary one, in an isothermal process (of equal temperature), the entropy change (S2 - S1) will be equal to the amount of heat to exchange the system with theenvironment , (Q1 → Q2), divided by its temperature. This is expressed by the following equation:
S2 - S1 = (Q1 → Q2) / T
This shows that the entropy variations can only be calculated in a system and not absolute values.The only point where the entropy is zero is at absolute zero (0 K or -273.16 ° C).
Negative entropy
Negative entropy, syntropy or negentropy is that entropy that a system exports or releases to keep its entropy levels low.
This concept was developed by the physicist Erwin Schrödinger in 1943 and later taken up by various scholars.
Examples of entropy
Some everyday examples of entropy are:
- The breaking of a plate. If we understand the plate as an ordered and balanced system, with a high entropic potential, we will see that its fragmentation into pieces is a natural, temporary event that does not happen spontaneously in the opposite direction.
- Radioactive decay. This process, also irreversible, leads toatoms unstable and high entropic load to become more stable (changing element). To do this, they release large amounts of energy, which is what we call radiation.
- The end of universe. Contemporary physics has warned of a theory of the end of the universe, called "heat death," which holds that the entropy in the universe will at some point reach an equilibrium, a point of maximum entropy at the end of the universe. movement and heat transfers, with which there will be no further evolution or change of any kind.