Breathtaking! We can extract energy from black holes

But how possible is it?

Is it possible to harness energy from black holes? It seems like an absurd idea, but physicists have long pondered whether black holes could be tapped for energy one day.

Physicists from Columbia University now made it possible. They have found a new way to extract energy from black holes.

Physicists suggest that it is possible to extract energy from black holes by breaking and rejoining magnetic field lines near the event horizon, the point from which nothing, not even light, can escape the black hole’s gravitational pull.

Luca Comisso, a research scientist at Columbia University and first author on the study, said, Black holes are commonly surrounded by a hot ‘soup’ of plasma particles that carry a magnetic field. Our theory shows that when magnetic field lines disconnect and reconnect, in just the right way, they can accelerate plasma particles to negative energies, and large amounts of black hole energy can be extracted.”

“This finding could allow astronomers to estimate the spin of black holes better, drive black hole energy emissions, and might even provide a source of energy for the needs of an advanced civilization.”

Physicists constructed their theory on the premise that reconnecting magnetic fields accelerates plasma particles in two distinct ways. One plasma flow is pushed against the black hole’s spin, while the other is impelled the spin’s direction and can get away from the clutches of the black hole, which releases power if the plasma gulped by the black hole has negative energy.

Plasma close to the event horizon
Plasma close to the event horizon about to be devoured by a rotating black hole. © CLASSICAL AND QUANTUM GRAVITY, 2015. REPRODUCED BY PERMISSION OF IOP PUBLISHING

Comisso said, “It can happen in a region called the ergosphere, where the spacetime continuum rotates so fast that every object spins in the same direction as the black hole.”

The ergosphere is the region located outside a rotating black hole, in which magnetic reconnection is extreme enough that plasma particles are accelerated to velocities approaching the speed of light.

Felipe Asenjo from Universidad Adolfo Ibanez in Chile said, “The high relative velocity between captured and escaping plasma streams allows the process to extract massive amounts of energy from the black hole.”

“We calculated that the process of plasma energization could reach an efficiency of 150 percent, much higher than any power plant operating on Earth. Achieving an efficiency greater than 100 percent is possible because black holes leak energy, which is given away for free to the plasma escaping from the black hole.”

According to physicists, this process of energy extraction might already be taking place in several black holes. And, that may be the reason behind black hole flares.

Asenjo said, “Our increased knowledge of how magnetic reconnection occurs in the vicinity of the black hole might be crucial for guiding our interpretation of current and future telescope observations of black holes, such as the ones by the Event Horizon Telescope.”

The study, Magnetic reconnection as a mechanism for energy extraction from rotating black holes, was funded by the National Science Foundation’s Windows on the Universe initiative, NASA, and Chile’s National Fund for Scientific and Technological Development.

Vyacheslav (Slava) Lukin, a program director at NSF, said“The ideas and concepts discussed in this work are truly fascinating. We look forward to the potential translation of seemingly esoteric studies of black hole astrophysics into the practical realm.”

Journal Reference:
  1. Luca Comisso and Felipe A. Asenjo. Magnetic reconnection as a mechanism for energy extraction from rotating black holes. Phys. Rev. D, 2021 DOI: 10.1103/PhysRevD.103.023014

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