The theory of general relativity, developed by Albert Einstein, turned our understanding of gravity upside down. According to it, gravity is the curvature of space-time by massive objects. Black holes are one of the most exciting predictions of this theory, but they raise many questions for scientists.
Black holes and singularities
Singularities are points in space-time where matter shrinks to infinite density and the laws of physics cease to apply. They occur during the gravitational collapse of massive stars. Nobel laureate Roger Penrose proved that singularities are the inevitable result of such a collapse.
However, these anomalies cause serious problems. The laws of physics that we know no longer work, and predictions become impossible. To understand the nature of singularities, scientists turn to quantum mechanics, a theory that describes the behavior of particles at the microscopic level.
Quantum mechanics and black holes
Quantum mechanics offers new tools for the study of black holes. One approach is “semiclassical gravity”, which combines the general theory of relativity with quantum mechanics. This allows us to investigate how quantum effects impact space-time.
One interesting phenomenon is “negative energy”, a phenomenon that is only possible in quantum mechanics. It creates scenarios that are not taken into account by classical physics. Under such conditions, “quantum cosmic censorship” – the idea that quantum effects hide singularities behind black hole event horizons – may arise.
Penrose’s inequality and quantum space censorship
The basis for the idea of space censorship is the Penrose inequality, which relates the mass of spacetime to the horizon area of a black hole. In quantum mechanics this inequality has received a new interpretation. In 2019, scientists proposed a quantum version of the inequality that took into account the entropy of black holes and quantum matter.
A recent study published in Physical Review Letters has advanced this quantum inequality by showing that the energy of spacetime is consistent with the second law of thermodynamics. This supports the idea that quantum effects keep the Universe predictable, even under the most extreme conditions.
Unresolved issues
Despite the significant progress made in understanding the quantum origin of spacetime, the grand unification of quantum mechanics and Einstein’s general theory of relativity remains elusive. The search for a universal theory of quantum gravity that reconciles these two pillars of modern physics is one of the greatest challenges facing theoretical physicists today.
Approaches such as string theory, loop quantum gravity, and causal dynamical triangulation offer promising ways to bridge the gap between the subatomic sphere and the large-scale structure of spacetime. However, the road to a complete and consistent theory of quantum gravity is full of technical and conceptual obstacles, requiring bold new ideas and innovative mathematical structures.
Quantum mechanics offers new ways to solve black hole mysteries. The idea of quantum cosmic censorship shows how quantum effects can prevent the observation of singularities while preserving physical laws. While many questions remain open, this research is a step toward unifying quantum mechanics and general relativity theory, which promises a deeper understanding of the Universe.
Earlier we reported on how physicists found an alternative to dark matter.
According to newscientist.com
