American physicist Avi Loeb suggested that alien civilizations could not only use black holes to get energy from them, but also create them artificially and place them in the orbit of their own planet.
Avi Loeb and black hole energy
Avi Loeb, an Israeli-born American physicist, is one of the most genius and most scandalous scientists of our time. It was he who suggested using the gravitational lensing effect 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 could be an alien spacecraft.
Loeb makes a lot of assumptions that look too audacious and sometimes just crazy in the eyes of other scientists and, nevertheless, some of them turn out to be true more often than they would be if he were just randomly guessing.
Loeb’s new work is also about black holes. This time he suggested that a sufficiently advanced alien civilization could use their energy, and we could see it from great distances.
Actually, this idea is not Loeb’s. Roger Penrose put it forward back in 1971. After all, despite the fact that these objects don’t emit anything, in the accretion disk, the matter rotates very fast and heats up very strongly.
Black holes orbiting planets
Penrose’s original idea was to use the kinetic energy of the accretion disk. It is also one of the possible explanations for the Fermi paradox. We don’t see aliens because all sufficiently advanced civilizations have long ago migrated to black holes.
Loeb agrees with all of this, but notes that there are other ways. For example, to use the thermal energy of the accretion disk. But first he thinks about Hawking radiation. This phenomenon keeps information from disappearing forever in a black hole, but it’s usually too weak to use.
Loeb says it may allow extraterrestrial civilization to use black holes in a really new way. He had previously suggested how such an object could be created without a supernova explosion. And it is now believed that aliens could use this method to create a singularity with a mass of only 100,000 tons that would orbit the planet like a moon.
Usually the long-term existence of such objects is considered impossible, because of the same Hawking radiation. Because of it, such a small black hole “evaporated” only for a year and a half. However, Loeb calculated that if every second “fed” it only 2.2 kg of matter, its mass can be maintained indefinitely.
Why this is beneficial to civilizations
The main attraction of this scheme, according to Avi Loeb, is that the entire mass of matter dropped on the black hole will eventually turn into energy. And this is only one of two known processes in which this can happen.
The second is annihilation, that is, the reaction between ordinary matter and antimatter. However, the latter is extremely difficult to extract and store in large quantities. A black hole, according to the scientist, is simpler. And any kind of garbage can be used as fuel.
And even mankind is already producing about 2 billion tons of it every year. It would be enough to feed a black hole. So, if a civilization succeeds in this task, it can provide its planet with energy and avoid depending on its own star altogether. Therefore, taking a closer look at orphan planets, it is possible to find life among them.
According to phys.org
