Currently, during the flourishing of various kinds of films that take place in space, acts of ultra-fast movement of ships in outer space have become popular. This is achieved by a sharp increase in the speed of the vessel to a superluminal value. In this regard, theories are already emerging, the purpose of which is to scientifically prove the reliability of this process.
Miguel Alcubierre
This person is a representative of theoretical physics. Alcubierre is known for its so-called Alcubierre engine. The phenomenon described by Miguel is based on the statement about the ability of a spacecraft to move at a speed above the speed of light (in general, at absolutely any speed), bending the space in front and behind it.
Alcubierre is a native of Mexico. His year of birth is 1964. He married Maria Emilie Beyer and they had a daughter. Miguel currently has four children.
Alculberre Bubble
The Alcubierre bubble, or Alcubierre engine (or Alcubierre metric, referring to the metric tensor) is a speculative theory that is based on solving equationsgravitational field (Einstein's equation) in general relativity, it was proposed by a Mexican theoretical physicist named Alcubierre. According to this theory, a spacecraft is able to overtake something faster than light, but with the condition that the energy density of the field is less than in vacuum (the phenomenon of negative mass).
Instead of exceeding the speed of light within the local CO, the spacecraft will cover distances by changing space (contracting it in front and expanding it behind it), which will lead to extremely fast movement of this object. This kind of space distortion is called the Alcubierre bubble. According to the laws of physics, bodies cannot be accelerated to the speed of light within the framework of the natural position of space and time; instead, according to Alcubierre's theory, the body will move space around itself in such a way that it arrives at its destination faster than light, without violating any physical laws.
Reason why such a movement cannot be realized
Although Alcubierre's metric is consistent with Einstein's field equations, it may not have physical meaning, in which case no such motion will occur. Even if it is physically significant, its possibility will not necessarily mean that the vessel can be built. The proposed Alcubierre engine mechanism implies a negative energy density and therefore requires an unknownsubstances. So if unknown matter with the correct properties cannot exist, then it is impossible to build a drive. However, at the end of his original paper, Alcubierre argued (following an argument developed by physicists analyzing traversable wormholes) that a Casimir vacuum between parallel plates could satisfy the negative energy requirement for Alcubierre's engine.
Another possible problem is that although the Alcubierre bubble is consistent with Einstein's equations, general relativity does not take into account quantum mechanics. Some physicists have presented arguments that a theory of quantum gravity (which would include both theories) would rule out those solutions in general relativity that allow backward time travel (the chronology protection hypothesis) and thus invalidate Alcubierre's theory.
Sergey Krasnikov
Sergey Krasnikov is a Russian theoretical physicist. He developed his own theory called "Krasnikov's tube", which states that it is possible to move in space at the speed of light.
Krasnikov's Trumpet
Krasnikov's tube is a speculative theory about cosmic movements, the basis of which is the deformation of space and time in the design of a pipe (tunnel). The result is comparable to a wormhole, the extreme points of which are displaced in time and space. The theory was proposed and theoretically explained by Sergey Krasnikov in 1995.
Tube is an altered space-time construct that can be deliberately obtained (using certain technology) as a result of moving at the speed of light. Krasnikov's tube allows you to return to the past immediately after you left. This man-made "tube" some number of light years long may be a megastructure, but unlike other megastructures, it is not made of physical matter like titanium or plastic, but is simply a distortion of spacetime.
Krasnikov's pipe. Single pipe case
Krasnikov expresses the opinion that despite the time machine, as an aspect of his metric, it still does not have the right to violate the law of causation (the cause precedes the effect in all systems and along the entire space-time path), since all points along the annular path of the ship at a superluminal speed are always ordered in time and are divided into certain intervals (in algebraic expressions, c2dt2 is, by definition, greater than dx2 + dy2 + dz2). And this, in turn, means that the light message sent through the Krasnikov tube will not be used to transmit signals "back in time".
Two Pipe Case
While a single Krasnikov tube poses no problem of causation, Allen E. Everett and Thomas A. Roman of Tufts University suggested that two Krasnikov tubes going toopposite to each other, are able to create a closed, like time, curve that would break the causal relationship. For example, let's just assume that a tube is built connecting the earth to a certain star located 3,000 light-years away. Astronauts travel at such speeds that it takes only a year and a half (from their point of view) to travel through this tube. The astronauts then laid a second tube instead of returning to the first they had produced. After another year and a half of ship time, they will return to Earth, but already after 6 thousand years in the future of their departure. But now, when both Krasnikov tubes are in place, astronauts from the future are able to travel to the star in the second tube, and then to Earth through the first tube, but they will reach the end point of the route 6 thousand years before their departure. Krasnikov's system of two pipes has turned into a time machine.
In 1993, Matt Visser argued that a pair of wormholes with an induced clock difference would not be able to combine without causing effects that would either destroy the wormhole or simply interact with each other in the form of repulsion. This statement suggests that such a situation would not allow a time machine to appear from a pair of Krasnikov pipes. That is, the vacuum fluctuation will grow exponentially, and eventually destroy the second Krasnikov tube as it approaches the limit of a circle similar to time, in which causality is violated.
Alcubierre bubble or Krasnikov's pipe
Each of these theories suggeststhe implementation of the distortion of space-time and the movement of the spacecraft with the speed of light (under certain conditions). Scholars well-versed in the field say something like this:
Changing the position of the body in space at the speed of light is possible. It is only necessary to move either in a bubble in which space and time are bent, or in a pipe (tunnel) that can connect the diametrical points of the world (space)
That is, for the interpretation of the essence of movement with light speed and its subsequent explanation, these theories are equally suitable as they are not.
