Fifty years ago, the English mathematical physicist and Nobel Prize winner Roger Penrose proposed that energy could be extracted from space around a rotating black hole. This region, also known as the ergosphere, lies just outside an event horizon, the boundary within which nothing can escape a black hole’s gravity (even light). This is also where the dumping of material accelerates to incredible speeds and releases all kinds of energy.
This became known as the Penrose process, to which many theorists have since expanded. The latest comes from a study conducted by researchers from Columbia University and the Universidad Adolfo Ibáñez in Chile. With the support of organizations like NASA, they have shown how a better understanding of physics at work around the turning of black holes can enable us to harness their energy one day.
The study, entitled “Magnetic Reconnection as a Mechanism for Energy Extraction from Rotating Black Holes,” was conducted by Luca Comisso and Felipe A. Asenjo. In it, they propose a new method by which energy can be harnessed from a black hole by breaking magnetic fields and closing them again, the boundary within which nothing can escape the gravity of a black hole (even light).
Like Comisso, a research scientist at Columbia University and the first author of the study explained in a Columbia News press release:
‘Black holes are usually surrounded by a hot’ soup ‘of plasma particles carrying a magnetic field. 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. ”
While Penrose theorized in 1971 that this process of particle disintegration can draw energy from a black hole, Stephen Hawking suggested in 1974 that black holes could release energy through quantum mechanical emission (known as Hawking radiation). This was followed by Roger Blandford and Roman Znajek who in 1977 suggested that electromagnetic torque was the main means of energy extraction.
For the sake of their study, Comisso and Senjo consider an important part of the Penrose process, that is, how magnetic field lines break apart and reconnect near the horizon of the event. This causes the pouring material to change into two streams of charged particles (also known as plasma), one of which is pushed upwards at the turn of the black hole and picks up negative mass energy, which will fall beyond the horizon into the black hole. .
Meanwhile, the other plasma flow will be driven in the same direction as the rotation of the black hole, so that it can absorb extra mass energy and escape to the ergosphere. Within the ergosphere, the reconnection of magnetic field lines is so extreme that the plasma particles accelerate to velocities approaching the speed of light (also known as relativistic velocities).
What this essentially means is that a black hole will lose energy by eating particles with negative mass energy. What’s more, the high relative velocity between captured and escaping plasma currents is what enables the process where massive amounts of energy can be extracted from a black hole. Asenjo, professor of physics at the Universidad Adolfo Ibáñez and co-author of the study, explained:
‘We have calculated that the process of plasma energy can achieve an efficiency of 150 percent, much higher than any power plant operating on earth. 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 this may sound like science fiction, it is quite possible that future generations will look to black holes to meet their energy needs. What’s more, Comisso and Asenjo argue, the process of energy extraction may already be taking place with a number of black holes in the observable universe. This could be the reason for torches with black holes, which are powerful eruptions that can be detected from the earth.
“Thousands or millions of years from now, humanity can survive over a black hole without harnessing energy from stars,” Comisso said. ‘It’s essentially a technological problem. If we look at physics, there is nothing that prevents it. ”
In fact, it is possible that sufficiently advanced species in our universe are already using black holes for their unlimited energy. Such a scenario was recently suggested in a paper by Marion Cromb, a doctor. astrophysics student from the University of Glasgow’s School of Physics and Astronomy. It is also part of the Transcension Hypothesis, a proposed resolution to the Fermi Paradox that Roger Smart originally proposed in 2002.
In addition to being an ultimate source of power, Smart also proposed that black holes be a ‘transcendent’ (super-advanced) species, a computationally optimal domain of increasingly dense, productive, miniaturized, and efficient scales of space, time, energy, and matter. There is even the possibility of exploring alternative physics models, anticipating time travel and seeing the ‘seeds’ of new universe!
There are also theories about how small black holes can be used to drive interstellar spacecraft (the black hole drive), or how an event horizon can become a means of propulsion (the Halo Drive). This latter idea works in the same way as a gravity maneuver, where a spacecraft would use the event horizon of a rotating black hole to make itself turn to distant stars at speeds approaching the speed of light.
But in the meantime, studies like these are part of a growing effort to expand our knowledge of black holes and the exotic physics that take place in their environment. As Asenjo pointed out, theoretical studies on black hole physics are especially important at a time when global efforts such as the Event Horizon Telescope (EHT) allow the first photographs of black holes to be captured:
“Our increased knowledge of how magnetic reconnection occurs in the vicinity of the black hole could be crucial to the interpretation of current and future telescope observations of black holes, such as those through the Event Horizon Telescope.”
The study, which recently appeared in the scientific journal Physical overview D, was made possible by funding from NASA, the National Fund for Scientific and Technological Development (FONDECYT), and the National Science Foundation (NSF), Chile Windows on the universe initiative – a synthesis program aimed at bringing theoretical physics and observational theory under one roof to answer some of the deepest questions.
Further reading: Columbia News, Physical overview D