Scientists have been wrestling for decades with a complex mystery of physics: can the enormous amounts of energy theoretically produced by rotating black holes ever be tapped by human hands?
If future societies could somehow achieve this amazing feat, the power supply of distant galactic civilizations would apparently be assured – and now scientists have a new explanation for how such an exotic exploitation would one day be possible.
“Black holes are usually surrounded by a hot ‘soup’ of plasma particles carrying a magnetic field,” explains astrophysicist Luca Comisso of Columbia University.
“Our theory shows that when magnetic field lines are properly disconnected and reconnected, it can accelerate plasma particles to negative energies and large amounts of black hole energy can be extracted.”
Comisso’s new work – co-author of the physicist Felipe A. Asenjo of the Universidad Adolfo Ibáñez in Chile – offers a new prism to see how energy extraction can work out of a spinning black hole.
Given their extreme mass, it is only natural to assume that black holes also contain a lot of energy. Unfortunately, it was all locked up at the bottom of a slippery pit of space-time.
Under conditions where the mass rotates, it may be possible to dip a tone into this enormous energy pool if the slopes of space-time are dragged along.
Former Oxford University physicist and mathematician Roger Penrose proposes one ingenious method. In what became known as the Penrose process, energy can theoretically be extracted from the region beyond the horizon of the black hole, the ergosphere, within which space-time is distorted due to the effects of the rotation of the black hole.
Penrose’s calculations suggested that if a particle were divided into two parts in the ergosphere, with one piece in the event horizon and the other one escaping the gravity of the black hole, the energy escaping through the object could theoretically be extracted. become, if it were practically impossible.
This famous idea was experimentally verified by scientists in an article published only a few months ago, but it is not the only way to harness energy in a spinning black hole.
Hawking radiation, based on quantum mechanical emissions, is another way, known as the Blandford-Znajek process, in which energy can be extracted electromagnetically via the magnetic field around a black hole.
In Comisso and Asenjo’s analysis, magnetism also plays a central role – specifically, as magnetic field lines within the ergosphere break and reconnect, but it also repeats the thinking of the Penrose process.
As magnetic reconnections occur outside the event horizon – splitting of plasma particles accelerates to velocities approaching the speed of light in two different directions, one plasma flow can fall into the event horizon, while the other can escape.
From the perspective of the black hole, the particle would be permeated with a negative amount of energy. From outside the black hole, the emerging particle will have positive energy that can be put to work.
By escaping this method, plasma streams with replenished energy can theoretically serve as a virtually unlimited source of free energy, as long as the black hole swallows negative energy plasma, that is.
“We have calculated that the process of plasma energy can reach an efficiency of 150 percent, much higher than any power station operating on earth,” explains Asenjo.
“Achieving an efficiency of more than 100 percent is possible because black holes leak energy, which is given away for free to the plasma escaping from the black hole.”
While it is probably unlikely that we will be able to utilize this energy generation practically in any way, it does not mean that it is completely useless.
From an astronomical perspective, the phenomenon could be the effects of black holes, which means large releases of radiant energy into space.
“Unlike the Blandford-Znajek process, in which the extraction of rotational energy is obtained by a pure electromagnetic mechanism, the mechanism for extraction of energy requires non-zero particle inertia,” the authors write.
“This mechanism is also different from the original Penrose process, as magnetic energy dissipation is required to produce the particles with negative energy. It is clear that all mechanisms extract the rotational energy from the black hole through the black hole with negative energy. energy and angular momentum. “
The findings are presented in Physical overview D.