What To Know
- A ball flasha German term meaning “ball lightning,” refers to a hypothetical black hole that would form not from ordinary matter, but from a huge concentration of electromagnetic radiationsuch as light.
- In this study, researchers from the University of Waterloo and the Perimeter Institute for Theoretical Physics explored the impact of quantum effects on the formation of kügelblitze.
- They found that we are at more than 50 orders of magnitude of the required intensitymeaning the energy required would be billions of times greater than what we can currently produce.
Black holes are among the most fascinating and mysterious phenomena in the Universe. Traditionally, they form when massive stars collapse under their own gravity at the end of their life cycle. However, more exotic hypotheses have been proposed, including that of “kügelblitze”, black holes formed solely by the concentration of light. But are they really possible?
The nature of the Kügelblitze
A ball flasha German term meaning “ball lightning,” refers to a hypothetical black hole that would form not from ordinary matter, but from a huge concentration of electromagnetic radiationsuch as light. In the theory of general relativity ofEinsteineven though it has no mass, energy can indeed bend spacetime and create a gravitational pull. Theoretically, if enough light is concentrated into an extremely small volume, it could generate a gravitational field strong enough to form a black hole. However, these concepts rely on classical general relativity which does not take into account quantum phenomenawhich brings us to this new work. In this study, researchers from the University of Waterloo and the Perimeter Institute for Theoretical Physics explored the impact of quantum effects on the formation of kügelblitze.
Impossible mission
The researchers here studied a phenomenon called the Schwinger effectalso known as vacuum polarization. This effect occurs when extremely intense electromagnetic fields transform some of their energy into matter, creating pairs of particles called electrons and positrons. During their research, the scientists calculated the rate at which these particle pairs consume the energy of the electromagnetic field. If these particles use up the energy faster than the field can replenish it, then a black hole made entirely of light (or kügelblitz) cannot form. Their results showed that even under extremely intense conditions, pure light can never reach the necessary energy level to form a black hole. Researchers have found that even using the most powerful lasers available on Earth, we are still far from reaching the intensity needed to create a kügelblitz. They found that we are at more than 50 orders of magnitude of the required intensitymeaning the energy required would be billions of times greater than what we can currently produce.
Credits: NASA/JPL-Caltech
What theoretical implications?
This discovery has profound theoretical implications, and challenges astrophysical and cosmological models that assumed the existence of kügelblitze. Although the idea of black holes formed only of light is fascinating, this study shows that they cannot exist in our Universe when we take into account quantum phenomena. It also rules out the possibility of studying black holes in the laboratory by creating them by concentrating light. Nevertheless, the study demonstrates that quantum effects can be effectively integrated into problems involving gravity, providing clear answers to complex scientific questions. Inspired by these findings, the researchers plan to continue exploring the influence of quantum effects on various gravitational phenomena. Studying the gravitational properties of quantum matter could indeed reveal exotic aspects of spacetime such as repulsive gravity or exotic solutions such as the Alcubierre warp or traversable wormholes. Details of the study are published in the Physical Review Letters.
