For decades, scientists have struggled with a complex mystery of physics: could huge amounts of energy theoretically produced by the rotation of black holes ever be exploited by human hands?
If future societies were somehow able to put an end to this magnificent fact, the energy supply of distant galactic civilizations would apparently be assured – and now scientists have a new explanation for how such an exotic extraction could be in a way. possible day.
“Black holes are usually surrounded by a hot ‘soup’ of plasma particles that carries a magnetic field,” explains astrophysicist Luca Comisso of Columbia University.
“Our theory shows that when magnetic field lines are disconnected and reconnected correctly, they can accelerate plasma particles to negative energies and large amounts of black hole energy can be extracted.”
Comisso’s new work – co-written by physicist Felipe A. Asenjo of the Universidad Adolfo Ibáñez in Chile – offers a new perspective on how energy extraction from a spinning black hole might work.
Given their extreme mass, it is natural to assume that black holes also contain an extreme amount of energy. Unfortunately, everything is locked in the bottom of a slippery space-time pit.
As that table rotates, it may be possible to immerse a toe in this huge pool of energy as the slopes of space-time are drawn.
The eminent physicist and mathematician of the University of Oxford, Roger Penrose, suggests an ingenious method. In what became known as the Penrose process, energy could theoretically be extracted from the region outside the event horizon of a black hole, called the ergosphere, in which space-time revolves around the effects of black hole rotation.
Penrose’s calculations suggested that if a particle split into two parts inside the ergosphere, with one piece falling on the horizon of events and the other escaping the gravitational attraction of the black hole, the energy obtained by the escaping object would be theoretically extractable, if practically impossible. .
This famous idea was experimentally verified by scientists in a paper published only a few months ago, but it is not the only suggested way to harness the energy of a spinning black hole.
Hawking radiation, based on quantum mechanical emissions, is another mode, just like what is known as the Blandford-Znajek process, in which energy could be extracted electromagnetically by the magnetic field around a black hole.
In Comisso and Asenjo’s analysis, magnetism also plays a central role – specifically, as the lines of the magnetic field break and reunite within the ergosphere – but it also restores some of Penrose’s thinking.
As magnetic reconnections take place outside the event horizon – split plasma particles accelerated to speeds approaching the speed of light in two different directions – one plasma flux could fall to the event horizon and the other escape.
From the perspective of the black hole, the falling particle would be impregnated with a negative amount of energy. Outside the black hole, the particle coming out would have positive energy that could be put into operation.
By this method, the discharge of completed energy plasma streams could theoretically serve as a virtually unlimited source of free energy, as long as the black hole continues to swallow negative energy plasma, ie.
“We calculated that the plasma energization process can reach an efficiency of 150%, much higher than any power plant operating on Earth,” explains Asenjo.
“Achieving greater than 100% efficiency is possible because black holes drain energy, which is provided free of charge to the plasma coming out of the black hole.”
Although it is unlikely that we will ever be able to exploit this generation of energy in a practical way in practical terms, this does not mean that it is completely useless.
From an astronomical perspective, the phenomenon could be what powers black hole missiles – representing vast releases of radiation energy that go untapped into space.
“Unlike the Blandford-Znajek process, in which the extraction of rotational energy is obtained by a purely electromagnetic mechanism, the energy extraction mechanism described here requires inertia of non-zero particles,” the authors write.
“This mechanism is also different from the original Penrose process, because the dissipation of magnetic energy is required to produce negative energy particles. Clearly, all mechanisms extract the rotational energy of the black hole by feeding the black hole with negative energy and angular momentum. . “
The findings are reported in Physical review D.