Time to turn back inside the black hole

Scientists at the University of California (USA) discovered that time does not always go forward, at least inside black holes.

What is inside the black hole?

In a study published Aug. 15 in the Physical Review Letter, two American scientists Raphael Bousso and Netta Engelhardt at the University of California, USA, proposed another hypothesis about the black hole event horizon, showing that The time inside the black hole has the opposite characteristic of external events.

A black hole is a region of space - time has a huge gravitational field, preventing everything including light from escaping. The perimeter around the black hole at which everything cannot return is called the event horizon.

In 1974, American physicist Stephen Hawking proposed that black holes are slowly evaporating due to quantum effects around the event horizon. This evaporation occurs with all the information confined inside by tremendous gravity. This contradicts quantum physics, that information about a system cannot be permanently erased.

Illustration of a swirling black-hole superconducting NGC 1365. (Photo: NASA).

To explain this paradox, scientists in the 1990s thought that the information inside the black hole did not disappear but preserved in the form of surface fluctuations of the event horizon. Accordingly, the existence of a black hole in three-dimensional space can be interpreted as a flat screen for stereoscopic images through holography.

In the report, Engelhardt and Bousso developed a law that showed the direction of the course of a flat screen."The all-flat screen is seen as a border of a large area," Christian Science Monitor quoted Engelhardt.

Two types of flat screen images, future displays and past displays, correspond to two different gravity fields. Future full-screen images associated with gravity have a tendency to pull things together. In contrast, the past full-screen screen appears with gravity, which tends to push matter apart.

Thus, the timeline within each region is different. Our universe can be described by the second case, a screen of the past image, where time moves forward.The black hole is a futuristic image, in which matter is sucked in by the immense gravitational field. Therefore, time will drift back inside the eternal darkness of the black hole.

"In general relativity, no one can observe the black hole event horizon in a finite time. At the same time, the black hole is not an entity that sees the infinite future. just a convenient way to describe black holes , ' Engelhardt said.