Physicists Frans Pretorius of Princeton University (USA) and William East of the Canadian Institute for Theoretical Physics have found that black holes can potentially arise anywhere in the universe, including in the immediate vicinity of the Earth. The reason for the appearance of an exotic object in this case is the interaction between two gravitational waves. At the same time, this event is very unlikely, although in principle it is possible. This is reported by Science Alert.
In theoretical physics, gravitational waves are called perturbations of space-time, which can occur when massive exotic objects collide - neutron stars or black holes. The existence of such ripples was predicted by the general theory of relativity proposed by Einstein in 1915-1916, but for the first time gravitational waves were registered only in September 2015. The disturbances are generated by the collision of a pair of black holes located 13 billion light-years from Earth.
The gravitational wave, which has arisen during such a catastrophic event, initially has a large curvature, but over time, the front, expanding, becomes flatter. If two plane waves collide, then at a certain point for some time a singularity may appear - a region in which the curvature of space-time becomes infinite. However, the singularity disappears as soon as the waves diverge.
In a new work, published in the arXiv preprint repository, scientists have proposed a scenario for the appearance of a singularity that lives for a long time in the form of a black hole. According to physicists, this is feasible when a curved front of a gravitational wave meets a plane front of another wave. In this case, a sufficient amount of energy should be released, which is necessary to "fold" space into a black hole. In this case, the original gravitational waves would literally tear the Earth apart if they passed through it. However, the recorded space-time perturbations do not exceed the proton scales.
As shown by the researchers, when high-energy particles collide, gravitational waves with a flat front can also form, which, under certain conditions, can become a likely cause of a black hole.