American physicist Avi Loeb suggested that extraterrestrial civilizations could not only use black holes to generate energy, but also create them artificially and place them into the orbit of their own planet.
Avi Loeb and the energy of black holes
Avi Loeb, an Israeli-born American physicist, is one of the most brilliant and scandalous scientists of our time. It was he who proposed using gravitational lensing to search for exoplanets, predicted the existence of pulsars near the supermassive black hole at the center of our galaxy, and suggested that the asteroid Oumuamua might be an alien spacecraft.
Loeb makes many assumptions that seem too bold and sometimes downright crazy in the eyes of other scientists, and yet some of them turn out to be true more often than if he had guessed purely by chance.
Loeb’s new work also involves black holes. This time he suggested that a sufficiently advanced alien civilization could harness their energy and we could see them from a great distance.
In fact, this idea did not originate with Loeb. Roger Penrose put it forward in 1971. Although these objects do not emit anything, the matter in the accretion disk rotates very quickly and heats up very strongly.
Black holes orbit planets
Penrose’s original idea was to use the kinetic energy of the accretion disk. This is also one of the possible explanations for the Fermi paradox. We don’t see aliens because all sufficiently advanced civilizations migrated into black holes long ago.
Loeb agrees, but notes that there are other possibilities. For example, using the thermal energy of the accretion disk. But first he is thinking of Hawking radiation. This phenomenon prevents information from disappearing forever in a black hole, but is usually too weak to be used.
Loeb says it could allow alien civilizations to use black holes in a whole new way. He had previously proposed how such an object could be created without a supernova explosion. And now it is thought that using this method, aliens could create a singularity with a mass of just 100,000 tons that would orbit the planet like a moon.
Usually, the long-term existence of such objects is considered impossible due to Hawking radiation. For this reason, such a small black hole “evaporated” only in a year and a half. However, Loeb calculated that its mass could be maintained indefinitely if it was “fed” only 2.2 kg of matter every second.
Why this is beneficial for civilizations
The main advantage of this scheme, according to Avi Loeb, is that all the mass of matter falling onto the black hole is ultimately converted into energy. And this is only one of two known processes by which this can happen.
The second is annihilation, the reaction between ordinary matter and antimatter. The latter, however, is extremely difficult to extract and store in large quantities. A black hole, says the scientist, is easier. And any kind of waste can be used as fuel.
And humanity already produces about 2 billion tons of it annually. That would be enough to feed a black hole. So if a civilization successfully accomplishes this task, it can power its planet and completely avoid dependence on its own star. So if you take a closer look at orphaned planets, it is possible to find life there.
According to phys.org
