We somehow focus too much on the little green men, but space may well be populated by machines. Soulless self-replicating robot probes for whom neither distance nor time matters. From time to time emerging from the universal darkness, they can decisively participate in the life of civilizations, including this one.
What do they think about this on Earth?
The idea of self-replicating machines plowing the vastness of space is not new. Its foundation was laid in the middle of the last century by the outstanding American mathematician John von Neumann. The one with the name of which the architecture of most modern computers is associated (von Neumann architecture). It is worth noting that he did not consider his idea in relation to space, it was already done after him. Now the term "von Neumann probe" is usually understood as a space probe (apparatus, ship), which is sent into space by its creators for a specific purpose: neutral (research), or destructive or creative. Reaching a star system that has the necessary resources, the probe creates copies of itself, which continue to fulfill the will of their creators.
In space, where the distances between objects reach incredible values and it takes a huge amount of time to overcome them, not comparable to the life of living beings, von Neumann probes are an ideal tool for space exploration. In the conditions of almost limitless space, sending only one probe or even a thousand is not entirely rational. There should be enough of them so that they can visit as many stars as possible and find habitable worlds. Even now, scientists involved in the Breakthrough Starshot project, planning a flight to the Alpha Centauri star system (now officially called Rigel Centaurus), are talking about the creation of an entire fleet of microprobes. This is necessary, since not all sent probes will be able to withstand the extreme conditions of space or not meet an obstacle on their way. Certainly not all of them will safely reach the goal. Although we are not talking about self-replicating probes yet, this is not yet possible given our technology. But at the next stage, in the new mission, it will probably be so. Those probes that will fly to the nearest star system will find the necessary resource base there and, having created their own replicas, will send them to the stars closest to Alpha Centauri. Including in the direction of Altair.
It has been calculated that, propagating through our Galaxy at a speed of 10% of the speed of light, self-replicating probes can propagate along the Milky Way in half a million years.
Were we "seeded" by aliens?
Well, who hasn't asked himself what is the meaning of life? It is natural for a person to think about why he lives and what his purpose is. And what is the purpose of humanity? A civilization that has reached a high level of development may also be puzzled by the question of the meaning of its existence. Moreover, when its development reaches a level that is much superior to ours. As a rule, people see the meaning of life in children. They put their knowledge and life experience into them. The same answer can be reached by thinking about the meaning of the existence of an intelligent civilization. In the future, we will master the nearest worlds, humanity will live on Mars, planets near the nearest stars.But deep space, other galaxies, due to their vast distances, will probably not be available for our colonization. Should we not want to send probes-sowers there, so that after thousands, and perhaps millions of years of wandering around the Universe, they will find there a planet suitable for life, and create the basis for the origin of life. They took part in the terraforming of lifeless worlds, sowed the "seeds of life" there, controlled evolution and brought it to the appearance of life forms capable of creating civilization. Or, having discovered life there, they would have contributed to its evolutionary development to intelligent forms.
Now let's imagine that this idea has already occurred to someone. Well, for example, the inhabitants of the star system Beta Hounds of the Dogs. If there are any. This star is an analogue of the Sun, it is about 700 million years older than ours and is located at a distance of some 27 light years from us. And they came up with this idea 2, 5-3 million years ago. This is exactly the time of the appearance of the first of the genus Homo - Homo habilis. A skillful man who took the tools of labor in his hands and took the first step towards subjugating nature.
This is just an illustration, but if we assume that somewhere in the Universe there is another intelligent life, then it is hardly worth refuting the fact that it may seek to expand itself in space. Moreover, we can only be her “children”. We will not find evidence of this in the near future. And even if we find it, we will hardly accept it. But there are some interesting facts, or, it would be more correct to say, statements of some researchers, which may well fit into this theory.
For example, Milton Wainwright, an astrobiologist at the University of Sheffield, claims that he and his colleagues have discovered titanium microprobe balls in the upper atmosphere of our planet. According to him, they are filled with microorganisms of extraterrestrial origin. Of course, Nature and Science did not dare to publish an article about his discovery. But it was published in other lesser-known magazines. According to Wainwright's assumption, they could have been brought in by both comets and meteorites. The DNA of the biomaterial in the spheres and the spheres themselves are planned to be studied in detail. This was stated by Professor Chandra Wickramasingh, British physicist, astronomer and astrobiologist, one of the leading scientists developing the panspermia hypothesis and editor of the journal in which Wainwright's article was published.
Of course, it can be assumed that the microspheres could have come to Earth with meteorites or comets, but if they are of artificial origin, then their carrier could also be “man-made”. We are seriously considering the possibility of bringing terrestrial microorganisms to the planets and their satellites, to which we send our interplanetary probes. In this case, it cannot be ruled out that life was brought to Earth by accident by a reconnaissance probe from another star system.
Surveillance from space
If we were created, we would hardly be left unattended. Even if the reconnaissance probe accidentally discovered the civilization of the third planet from the Sun, then it would not fly away without leaving its copy to observe us. In the end, no matter how much an alien civilization is superior to us, it is worth watching us, you never know how we progress in the future. If they live close enough to us, we can be dangerous to them. Today we call their stars and planets by their proper names, tomorrow we will send our probes to them, and the day after tomorrow we will not share anything in space. When we reach a certain level of development, we will either be destroyed or forced to comply with general galactic rules. Remember the galactic zoo hypothesis.
Several years ago, Robert Wagner and Paul Davis from Arizona State University proposed a project to search for traces of the presence of representatives of extraterrestrial civilizations on the satellite of our planet. Their plan is somewhat similar to the SETI @ home project. NASA has hundreds of thousands of 50 cm by 1 pixel images of the lunar surface taken by the LRO probe since 2009.With the help of distribution networks, something interesting could be found in these images. Astrobiologist and cosmologist Paul Davis suggests the possibility of the existence of a probe on the Moon, which arrived in our system at the dawn of our civilization and is observing our development. Such probes may well travel through space, marking the birthplaces of life, and possibly helping it to survive. If Professor Davis's assumptions are correct, then it is quite possible that the probe, which arrived on the moon in the prehistoric period, took advantage of the resources of our satellite. Several copies of him flew from the moon into space, and he himself remained to look after our planet.
Berserkers may have visited our system before
Aliens can destroy us. In theory, yes. The only question is in the details. How will they do it? They will fly a great distance to destroy our civilization and watch us writhe in our dying cramps. Or they will send for this purpose their berserker probes, designed to utilize everything that we have created here over several thousand years of our almost intelligent existence. Rather, the second.
However, if the very existence of self-replicating probes is hardly worth doubting (if, of course, alien life exists somewhere), then their "range" can be questioned. Axel Kowald, a biophysicist at Newcastle University, believes that self-replicating probes have a limit of action. That is, these machines, no matter what purpose they may carry, will not be able to escape outside the sphere with a radius of 225 sv. years, the center of which is at the starting point of the flight. The reason for this lies in the so-called "error catastrophe". Kovald believes that reproduction without errors is impossible. These errors will accumulate from one generation of probes to the next. Each new generation of probes will lose their functionality. And over time, the process of their spread in space will stop.
This is a definite plus. If there is no civilization next to us, which is spreading berserker probes throughout this part of the Galaxy, designed to clear the living space, then for some time we can live in peace. However, Kovald himself believes that errors in self-replication can be corrected by "controllers" and the distribution limit can be bypassed. In addition, it can be added that scientists dealing with this issue, as a rule, do not take into account the not yet created methods of interstellar travel, for example, warp drive, etc. And, in the end, berserkers can penetrate to us through wormholes.
We do not see them, according to Kovald, because their creators had to come up with a camouflage system for them so that they would not be detected by representatives of other civilizations.
It is possible that berserkers have already visited the solar system. John Brandenburg, a physicist at the University of California, is searching for the causes of the death of a hypothetical Martian civilization. According to one of his versions, the cause of death is the "space conquistadors" - probes-berserkers. According to the scientist, it is possible that some highly developed civilization, sending probes-berserkers to all ends of the Universe, periodically destroys its potential rivals. Brandenburg calls for an expedition to be sent to the Red Planet as soon as possible to find out why Mars has become a lifeless planet. Perhaps the past of Mars will provide an answer to the question of what future may await the Earth.
An independent life form?
It was noted that the von Neumann probe's self-replication model has a certain similarity to how bacteria multiply. This means that, with some caveat, they can be considered as a form of life. It may also happen that, unlike the automatic probes that we send across the solar system, von Neumann probes are not under the control of their creators. They are too far from the starting point of their journey.Perhaps the civilizations that created them are long gone.
At the outset, we pointed out that it would take half a million years for the probes to propagate throughout the entire Milky Way. Such a period is a challenge to any civilization. Created for predetermined purposes, the probes carry out a program laid down in them, perhaps thousands, and possibly millions of years ago. They spread biological life in the Universe, or, conversely, destroy, observe the inhabitants of exoplanets or participate in it. And there is no reason to believe that they could not participate in our life or will not be able to participate in it in the future. Except for one thing - if, except on Earth, nowhere in the Universe there is more intelligent life.