Black and wormholes have long appeared in several sci-fi movies and series, in which space travelers travel through them to explore the universe.
What are black and wormholes? Is it possible to travel through time and space? What is real in science fiction movies? Russian physicists from universities participating in Project 5-100 answer these questions.
What is a black hole?
Physicists qualify a black hole as an area of spacetime where a gravitational field is generated so strong that no material particle, energy, not even information, including light, can escape this area when it falls into it.
The black hole is separated by an event horizon: the black hole’s frontier from which no object can come out, not even radiation. As such, observers outside the hole cannot know what happens inside.
According to the general theory of relativity, the geometry of black holes described by Einstein, which bind together the metric of the curved space-time with the properties of matter that fills it, with gravitation manifestation of curvature of spacetime, explains Kiril Bronnikov, a professor at the Russian University of Peoples Friendship in Moscow.
Scientists have described in theory various types of black holes. They are distinguished by their rotation or absence, electrical charge and other possible parameters. It is considered that black holes can arise when massive stars compress in the final stage of their evolution or due the fluctuations of very dense matter in the early universe,” said the scientist.
According to the expert, it is impossible to see a black hole because an outside observer cannot receive any information from the event horizon. Therefore, the black hole can only manifest itself indirectly: by bending light rays or electromagnetic radiation that the material particles falling into the hole emit, etc.
Scientists could not yet understand what represents the interior of the black holes, which lies behind the event horizon.
According to the general theory of relativity, these must contain so-called singularities, areas with very high values of spacetime curvature, density, and pressure of matter, while many scientists find this impossible.
“We have reached the frontier of our traditional conceptions of spacetime and have entered an area unknown to gravity theory that has not yet developed,” said Kiril Bronnikov.
He believes that there may be another type of black hole, the so-called black universe. It may look like any other black hole. Falling into it across the event horizon, the observer enters a new, widening universe.
Seeking black holes
In early 2019, the RadioAstron terrestrial and space interferometer observation program ended with thousands of times higher resolution than the famous Hubble telescope. RadioAstron includes dozens of more powerful terrestrial radio telescopes and a space observatory, coupled with special algorithms, forming a virtual plant whose diameter is larger than our planet.
The equipment allowed Russian astronomers to discover in the center of the OJ287, Cancer constellation, a pair of supermassive black holes within walking distance of one another, Yuri Kovalev of the Moscow Institute of Physics and Technology reported.
“Our observations correspond completely to the theoretical predictions. In the future, we plan to study in shorter waves using terrestrial and spatial interferometers around black holes. This will allow us to substantiate the theoretical ideas about the existence of other objects: the so-called “wormholes,” said the scientist.
Tunnels to other dimensions
Wormholes are the most curious objects in the universe and arouse intense debate among scientists. They are configurations of space-time in the form of tunnels between remote areas of our universe or even between various universes.
Wormholes are similar to black holes, being objects located with a strong gravity field and a curvature of space. Meanwhile, the difference with black holes is that they do not have the event horizon. Thus, in theory it is possible to get in and out of these holes, according to Serguei Rubin, a professor at the National University of Nuclear Investigations in Moscow.
Although wormholes do not contradict the theory of relativity and are predicted by various cosmological theories, none have been found. Moreover, wormholes predict a spacetime geometry that is not typical for maintaining a matter with exotic properties, for example with negative energy density.
Serguei Rubin does not share the opinion of astronomer Heino Falcke about the recent black hole shadow photographs in the center of the M87 galaxy, obtained by the Even Horizons Telescope project, which could confirm the existence of tunnels in the space-time structure. To draw definitive conclusions, greater accuracy of measurements is lacking.
How to get into a wormhole?
Not all portal films in other dimensions are far from current scientific theories, says Professor Artiom Yurov of the Baltic Federal University Immanuel Kant.
“In the Interstellar movie, information about black holes and additional spaces is in line with scientific theories. Not surprisingly, since the film’s scientific advisor was a Nobel Prize winner, the inspiring black hole physics expert Kip Thorne that gave new life to ideas about the existence of wormholes,” said the scientist.
He further adds that while wormholes may exist according to the laws of physics, they cannot arise independently. Meanwhile, a civilization with a high level of scientific and technological development could build them.
“There is no surprise. A Toyota car can not appear spontaneously. It is necessary to manufacture it,” said the scientist.
Physicists today think about the formation of wormholes that do not destroy quickly, as well as the possibility of making them too big for at least molecules to stay in and not destroy.
“Hypothetically you can send the human genome through a wormhole,” said Serguei Rubin.
Thus, in the future one may hypothetically send humanity from one dying universe to another that begins to live. It is not necessary to send a human being. You can send only the information, which will allow us to re-establish our civilization in a new universe.