The stellar universe is fraught with many mysteries. According to the general theory of relativity (GR), created by Einstein, we live in a four-dimensional space-time. It is curved, and gravity, familiar to all of us, is a manifestation of this property. Matter bends, "bends" the space around itself, and the more, the denser it is. 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 theories of gravity, of which there are hundreds today, differ from general relativity in details. However, all these astronomical hypotheses retain the main thing - the idea of curvature. If space is curved, then we can assume that it could take, for example, the shape of a pipe connecting areas that are separated by many light years. And perhaps even eras far from each other. After all, we are not talking about the space that is familiar to us, but about space-time when we consider the cosmos. A hole in itappear only under certain conditions. We invite you to take a closer look at such an interesting phenomenon as wormholes.
First ideas about wormholes
Deep space and its mysteries beckon. Thoughts about curvature appeared immediately after GR was published. L. Flamm, an Austrian physicist, already in 1916 said that spatial geometry can exist in the form of a kind of hole that connects two worlds. The mathematician N. Rosen and A. Einstein in 1935 noticed that the simplest solutions of equations in the framework of general relativity, describing isolated electrically charged or neutral sources that create gravitational fields, have a spatial "bridge" structure. That is, they connect two universes, two almost flat and identical space-times.
Later these spatial structures became known as "wormholes", which is a rather loose translation of the English word wormhole. A closer translation of it is "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, there is no need to specifically model the source of charge or mass. And a distant external observer, if the wormhole has microscopic dimensions, sees only a point source with a charge and mass when in one of these spaces.
Einstein-Rosen "Bridges"
Electric lines of force enter the burrow from one side, and from the other they exit, without ending or starting anywhere. J. Wheeler, an American physicist, said on this occasion that "charge without charge" and "mass without mass" are obtained. It is not at all necessary in this case to consider that the bridge serves to connect two different universes. No less appropriate would be the assumption that both "mouths" of a wormhole go out into the same universe, but at different times and at different points in it. It turns out something resembling a hollow "handle", if it is sewn to an almost flat familiar world. The lines of force enter the mouth, which can be understood as a negative charge (let's say an electron). The mouth from which they exit has a positive charge (positron). As for the masses, they will be the same on both sides.
Conditions for the formation of Einstein-Rosen "bridges"
This picture, for all its attractiveness, has not gained ground in particle physics, for a variety of reasons. It is not easy to attribute quantum properties to the Einstein-Rosen "bridges", which are indispensable in the microworld. Such a "bridge" is not formed at all for known values of the charges and masses of particles (protons or electrons). The "electrical" solution instead predicts a "bare" singularity, that is, a point where the electric field and the curvature of space become infinite. At such points, the conceptspace-time, even in the case of curvature, loses its meaning, since it is impossible to solve equations that have an infinite number of terms.
When does GR fail?
On its own, OTO specifically states exactly when it stops working. On the neck, in the narrowest place of the "bridge", there is a violation of the smoothness of the connection. And it must be said that it is rather nontrivial. From the position of a distant observer, time stops at this neck. What Rosen and Einstein thought was the throat is now defined as the event horizon of a black hole (whether charged or neutral). Rays or particles from different sides of the "bridge" fall on different "sections" of the horizon. And between its left and right parts, relatively speaking, there is a non-static area. In order to pass the area, it is impossible not to pass it.
Inability to pass through a black hole
A spaceship approaching the horizon of a relatively large black hole seems to freeze forever. Less and less often, signals from it reach … On the contrary, the horizon according to the ship's clock is reached in a finite time. When a ship (a beam of light or a particle) passes it, it will soon run into a singularity. This is where the curvature becomes infinite. In the singularity (still on the way to it), the extended body will inevitably be torn and crushed. This is the reality of how a black hole works.
Further research
In 1916-17. Reisner-Nordström and Schwarzschild solutions were obtained. In themspherically describes symmetrical electrically charged and neutral black holes. 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 D. A. 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-Nordström and Schwarzschild there really are wormholes in space. They are completely invisible to a distant observer, like black holes. And, like them, wormholes in space are eternal. But if the traveler penetrates beyond the horizon, they collapse so quickly that neither a ray of light nor a massive particle, let alone a ship, can fly through them. To fly to another mouth, bypassing the singularity, you need to move faster than light. Currently, physicists believe that supernova velocities of energy and matter are fundamentally impossible.
Black holes of Schwarzschild and Reisner-Nordström
The Schwarzschild black hole can be considered an impenetrable wormhole. As for the Reisner-Nordström black hole, it is somewhat more complicated, but also impassable. Still, it's not that hard to come up with and describe four-dimensional wormholes in space that could be traversed. You just need to choose the type of metric you need. The metric tensor, or metric, is a set of values that can be used to calculate the four-dimensional intervals that exist between event points. This set of values fully characterizes both the gravitational field andspace-time geometry. Geometrically traversable wormholes in space are even simpler than black holes. They do not have horizons that lead to cataclysms with the passage of time. At different points, time can go at a different pace, but it should not stop or speed up endlessly.
Two lines of wormhole research
Nature has put a barrier to the appearance of wormholes. However, a person is arranged in such a way that if there is an obstacle, there will always be those who want to overcome it. And scientists are no exception. The works of theorists who are engaged in the study of wormholes can be conditionally divided into two areas that complement each other. The first deals with the consideration of their consequences, assuming in advance that wormholes do exist. Representatives of the second direction are trying to understand from what and how they can appear, what conditions are necessary for their occurrence. There are more works in this direction than in the first one 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 is the material 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, and Sergei Krasnikov, recently came to this conclusion. The vacuum in this case is notemptiness. This is a quantum state characterized by the lowest energy, that is, a field in which there are no real particles. In this field, pairs of “virtual” particles constantly appear, disappearing before they are detected by devices, but leaving their mark in the form of an energy tensor, that is, an impulse characterized by unusual properties. Despite the fact that the quantum properties of matter are mainly manifested in the microcosm, the wormholes generated by them, under certain conditions, can reach significant sizes. One of Krasnikov's articles, by the way, is called "The Threat of Wormholes".
A question of philosophy
If wormholes are ever built or discovered, the field of philosophy concerned with the interpretation of science will face new challenges, and I must say, very difficult ones. For all the seemingly absurdity of time loops and the hard problems of causality, this area of science will probably figure it out someday. Just as they de alt with the problems of quantum mechanics and the theory of relativity created by Einstein. Space, space and time - all these questions have interested people in all ages and, apparently, will always interest us. It is almost impossible to know them completely. Space exploration is unlikely to ever be completed.
