The concept of emptiness for all its seeming simplicity is very complex and multivalued.
The answer to the question of what is emptiness is determined by the context in which it is put.
At first glance, everything is simple: Emptiness is a complete absence ... of what? For example, if there is not more coffee left in the coffee bank, they say that the bank is empty. But this is not so: the bank is filled with air. You can hermetically close the jar and draw out air from it, but even then it will not be completely empty. It will still have fields - gravitational, magnetic, and they, though not a substance, represent a form of existence of matter.
This situation makes us think about the fundamental possibility of the existence of emptiness.
"Nature does not tolerate emptiness" - this sayingFor many centuries Aristotle was an axiom for science. One of his confirmations was the principle of the pump: when the piston rises, a void forms beneath it. Nature seeks to immediately fill it with something, so the piston rushes water.
To a certain extent this principle worked. But in 1640 the Duke of Tuscany wanted to decorate the garden of his palace, located on a hill, with a fountain. The water was supposed to be pumped from the pond, which was located at the foot of the hill. Despite all the efforts of the masters, the water from the fountain pipe did not go. Nobody could understand what was happening: after all, the "fear of emptiness" had to drive water to any height!
Three years later, the court mathematician E.Torricelli explained the reason for the failure with the help of a well-known experiment: a cup with mercury capsizes the tube, which also contains mercury. "Living metal" slightly drops, forming a pillar, and above it - a void, called the Torricelli.
Thanks to this experience, it was not only openAtmospheric pressure, but also refuted the idea of a mythical "fear of emptiness." True, the Torricellian emptiness was not completely empty either, it was filled with mercury vapor, but for its time it was enough: the emptiness may well exist in nature.
Emptiness from the point of view of different sciences
Given the ambiguity of the concept of emptiness, each science puts its meaning into this word, and even there are different terms for denoting emptiness.
One such term is vacuum, which, in translation fromLatin means "empty". This is the name of a space where there is no matter, but there are fields. From a physical vacuum it is necessary to distinguish a technical vacuum-space filled with a highly rarefied gas. This happens, for example, in cathode ray tubes, a vacuum cleaner, or in vacuum packaging for food.
In astronomy, the term "void", which alsoIs translated from English as "emptiness", denote a space where there are no stars or galaxies. But such a space is not absolutely empty: it can have protogalactic clouds, as well as dark matter.
There is a concept of emptiness in computer science. In other words, this is called a null pointer and represents a variable that does not refer to any object.