Rotating black holes could hold the answer to future civilizations' energy needs. As Einstein predicted, these black holes have huge amounts of energy that could be tapped into.
The team worked out that energy can be extracted by breaking and rejoining magnetic field lines near the event horizon, where nothing escape's a black hole's gravitational pull.
The study was published in Physical Review D on Wednesday.
"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," said Luca Comisso, lead author of the study and research scientist at Columbia University.
Comisso also explained that their research could pave the way for astronomers to better calculate the spin of black holes, push black hole energy emissions, and may even be a source of power for future civilizations – perhaps living in deep space.
These black hole opposites would spew energy, be impossible to enter, and might even answer some of the universe’s fundamental questions. https://t.co/gHdEicTueN— Astronomy Magazine (@AstronomyMag) January 14, 2021
The theory behind the study focuses on the premise that reconnecting magnetic fields pushes forward plasma particles in two different directions. One goes against the direction of the black hole's spin, while the other moves in the same direction as the black hole spin, ultimately releasing power if the plasma the black hole takes in has negative energy.
This phenomenon happens in the ergosphere, "where the spacetime continuum rotates so fast that every object spins," explained Comisso. Inside the ergosphere, magnetic reconnection is so high that plasma particles move almost at the speed of light.
It's this process of high relative velocity between captured and escaping plasma that extracts huge amounts of energy from the black hole.
As Felipe Asenjo, co-author of the study and from the Universidad Adolfo Ibáñez, said "We calculated that the process of plasma energization can 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."
The researchers' study sheds light on what could help future civilizations harness power.
"Thousands or millions of years from now, humanity might be able to survive around a black hole without harnessing energy from stars," Comisso said. "It is essentially a technological problem. If we look at the physics, there is nothing that prevents it."