Finding the answer to the question of what a vacuum is is not as easy as it seems at first glance. This problem has worried scientists since ancient times, and even today there are several approaches that explain the physical side of this phenomenon.
Physical vacuum under the names "nothing", "ether", "meaningful emptiness" is considered in many philosophical concepts. Almost all of these theories emphasize that the main advantage of this “nothing” is that, unlike objects and phenomena familiar to us, it is devoid of any physical limitations. That is why it is considered as something universal, combining all existing characteristics and properties.
Another important aspect that stands out in many philosophical works is that the physical vacuum is the ontological basis of all existing objects and phenomena. Despite the fact that this space contains nothing in absolute terms, it is potentially the very factor that binds together all natural forces andprocesses.
Finally, if we turn to purely scientific aspects, it can be noted that despite the fact that the physical vacuum cannot be seen, its existence can be proved on the basis of numerous experiments. This includes the Casimir effect, the so-called electron-positron pair, and the Lamb-Rutherford effect. So, for example, the well-known Casimir effect is proof that even in an absolutely seemingly "empty" space, forces arise that force two plates to approach each other.
Modern science considers the physical vacuum from the point of view of the theory of quantum fields, according to which it represents the fundamental (or basic) state of any energy field encountered in the surrounding reality. A significant part of modern physicists agrees that any substance comes from this "airless space", from where it receives its basic properties and characteristics. Many go even further and try to prove that the physical vacuum is what our Universe arose from. For example, the well-known scientist Ya. Zeldovich in his work cites a number of provisions that such a concept absolutely does not contradict any of the objective laws discovered so far, except for the law of conservation of baryon charge, that is, the balance between matter and antimatter.
According to another modern approach, the physical vacuum is the lowest energy state in which any real particlesare simply absent. At the same time, these researchers agree that this special kind of matter is literally filled with all sorts of potential antiparticles and particles that can become real under the influence of external fields.
According to these ideas, in vacuum there is a continuous formation and disappearance of such pairs of elements as a positron and an electron, a nucleon and an antinucleon. They cannot be registered (at least not yet), but when a number of conditions are met, they become quite tangible.
