## Mole holes in space. Astronomical hypotheses

The star universe is fraught with many mysteries.According to the general theory of relativity (GTR), created by Einstein, we live in four-dimensional space-time. It is curved, and gravity, familiar to all of us, is a manifestation of this property. Matter warps, "bends" the space around itself, and the more it is denser. Space, space and time are all very interesting topics. After reading this article, you will surely learn something new about them.

## The idea of curvature

Many other gravitation theoriesthere are hundreds today, in details it differs from general relativity. However, all these astronomical hypotheses retain the basic idea of curvature. If the space is curved, then we can assume that it could take, for example, the shape of a pipe connecting regions that are separated by many light years. And perhaps even an era far from each other. After all, we are not talking about the space we are accustomed to, but about space-time, when we are considering the cosmos. A hole in it can appear only under certain conditions. We invite you to get acquainted with such an interesting phenomenon as wormholes.

## The first ideas about wormholes

The distant cosmos and its riddles beckon to itself.Thoughts about curvature appeared immediately after OTO was published. L. Flamm, an Austrian physicist, already in 1916 said that spatial geometry can exist in the form of a kind of burrow that connects the two worlds. Mathematician N. Rozen and A. Einstein in 1935 noted that the simplest solutions of equations in the framework of general relativity describing isolated electrically charged or neutral sources creating the gravitational field possess the spatial structure of the "bridge". That is, they connect the two universes, two almost flat and identical space-time.

Later, these spatial structures of steelcalled "wormholes", which is a fairly loose translation from English of the word wormhole. A closer translation of it is a "wormhole" (in space). Rosen and Einstein did not even rule out the possibility of using these "bridges" to describe elementary particles with their help. Indeed, in this case the particle is a purely spatial formation. Therefore, the need to model the source of charge or mass will not specifically appear. A remote external observer, in the event that the wormhole has microscopic dimensions, sees only a point source with charge and mass when in one of these spaces.

## "Bridges" of Einstein-Rosen

On the one hand, the hole includes electricthe lines of force, and on the other they come out, not ending and not starting anywhere. J. Wheeler, an American physicist, on this occasion said that it turns out "charge without charge" and "mass without mass." It is not necessary in this case to assume that the bridge serves to connect two different universes. Equally appropriate is the assumption that in the wormhole both "mouths" exit into the same universe, but at different times and at different points of it. It turns out something resembling a hollow "handle", if it is sewn to a practically flat familiar world. The lines of force enter the mouth, which can be understood as a negative charge (say, electron). The mouth from which they exit has a positive charge (positron). As for the masses, they will be the same on both sides.

## The conditions for the formation of "bridges" of Einstein-Rosen

This picture, for all its attractiveness, is notwas spread in the physics of elementary particles, for which there were many reasons. It is not easy to ascribe to the "bridges" Einstein-Rosen quantum properties, without which in the microcosm can not do. Such a "bridge" is not formed at all with known values of the charges and masses of the particles (protons or electrons). The "electric" solution instead predicts a "naked" singularity, that is, a point where the electric field and the curvature of space are made infinite. At such points, the concept of space-time, even in the case of curvature, loses its meaning, since it is impossible to solve equations having an infinite set of terms.

## When does GRT not work?

In itself, the UTO definitely states, whenit is she who stops working. At the neck, at the narrowest point of the "bridge", there is a violation of the smoothness of the joint. And it should be said that it is rather nontrivial. From the position of the remote observer, time stops at this throat. What Rosen and Einstein considered to be a throat is now defined as the horizon of events of a black hole (charged or neutral). Rays or particles from different sides of the "bridge" fall on different "areas" of the horizon. Strictly speaking, between the left and right parts of it there is a non-static region. In order to pass the region, you can not overcome it.

## Inability to pass through a black hole

A spaceship that is approachingthe horizon is quite large with respect to it a black hole, as if frozen forever. The signals from him get less and less frequent ... On the contrary, the horizon of the ship clock is reached in a finite time. When a ship (a ray of light or a particle) passes it, it soon rests on a singularity. This is the place where the curvature becomes infinite. In the singularity (still approaching it) the extended body will inevitably be torn and crushed. This is the reality of the device of a black hole.

## Further research

In the years 1916-17.The solutions of Reisner-Nordström and Schwarzschild were obtained. They symmetrically describe electrically charged and neutral black holes spherically. However, physicists were able to fully understand the complex geometry of these spaces only at the turn of the 1950s and 60s. It was then that DA Wheeler, known for his work in the theory of gravity and nuclear physics, proposed the terms "wormhole" and "black hole". It turned out that in the spaces of Reisner-Nordstrom and Schwarzschild there really exist wormholes in space. They are not completely visible to the remote observer, as well as black holes. And, like them, wormholes in the cosmos are eternal. But if the traveler penetrates the horizon, they collapse so quickly that no ray of light can fly through them, or a massive particle, and not just a ship. To fly to another mouth, avoiding the singularity, you need to move faster than light. At present, physicists believe that supernova velocities of energy and matter transfer are fundamentally impossible.

## Black holes Schwarzschild and Raisner-Nordström

The Schwarzschild black hole can be consideredimpassable wormhole. As for the Reissner-Nordstrom black hole, it is somewhat more complicated, but also impassable. Nevertheless, to come up with and describe the four-dimensional wormholes in space that could be traversed is not that difficult. It is only necessary to choose the necessary form of the metric. A metric tensor, or metric, is a set of quantities using which one can calculate the four-dimensional intervals existing between the event points. This set of quantities completely characterizes also the gravitational field, and the geometry of space-time. Geometrically passable wormholes in space are even easier than black holes. There are no horizons in them that lead to cataclysms with the passage of time. At different points, time can go at different tempos, but it should not stop or accelerate at the same time.

## Two directions of research of wormholes

Nature has put a barrier on the way of appearancewormholes. However, a person is arranged so that if there is an obstacle, there will always be those who want to overcome it. And scientists are no exception. Proceedings of theorists who are engaged in the study of wormholes, can be conditionally divided into two directions, complementing each other. The first is concerned with examining their consequences, in advance assuming that worm holes really exist. Representatives of the second direction are trying to understand what and how they can appear, what conditions are necessary for their occurrence. There are more works of this direction than the first and, perhaps, they are more interesting. This area includes the search for models of wormholes, as well as the study of their properties.

## Achievements of Russian physicists

As it turned out, the properties of matter, which ismaterial for the construction of wormholes, can be realized due to the polarization of the vacuum of quantum fields. Russian physicists Sergei Sushkov and Arkady Popov together with the Spanish researcher David Hochberg, as well as Sergei Krasnikov, recently came to this conclusion. Vacuum in this case is not an emptiness. This is a quantum state characterized by the lowest energy, that is, a field in which there are no real particles. In this field there are constantly pairs of particles of "virtual", disappearing before they are detected by devices, but leaving their mark in the form of an energy tensor, that is, a pulse characterized by unusual properties. Despite the fact that the quantum properties of matter are mainly manifested in the microcosm, the wormholes created by them, under certain conditions, can reach considerable dimensions. One of Krasnikov's articles, by the way, is called "The Threat of Worms."

## The question of philosophy

If worm holes ever happenconstruct or discover, the field of philosophy associated with the interpretation of science will face new challenges and, it must be said, very difficult. With all the seemingly absurdity of the temporary loops and the difficult problems related to causality, this area of science will probably someday deal with this. Just as we sorted out the problems of quantum mechanics and Einstein's theory of relativity. Space, space and time - all these issues have interested people in all ages and, probably, will always interest us. To know them completely is hardly possible. The study of outer space is unlikely to ever be completed.