Extraterrestrial civilization
Extraterrestrial civilizations are hypothetical civilizations that have arisen and are developing
Ideas about scientific and technological progress are given bythe possibility of suggesting that some extraterrestrial civilizations may be much more advanced than ours, since man appeared quite late by the standards of the age of the Universe.
This point of view is greatly facilitated by the association with them of the UFO phenomenon. It is possible, however, that our civilization, on the contrary, is the first and most developed in the Universe (or in the Milky Way).
Our Sun is a third generation star,formed from the remnants of second-generation supernovae, which in turn were formed from first-generation stars that appeared immediately after the Big Bang.
Planets around first generation stars are notcontained heavy elements, so life could not arise on them. The second generation stars were also not rich enough in heavy elements. For the development of stars of the first and second generations, up to their transformation into supernovae, in the depths of which heavy elements are formed, it took several billion years.
The solar system has existed for 4.5 billion years.of which approximately 4 billion was spent on the origin and evolution of life to man. Considering that the Universe is "only" 13.8 billion years old, it turns out that our civilization appeared quite early.
How to interact with extraterrestrial civilizations?
- Reasons for looking for a contact and possible consequences
Many people are excited about the idea ofcontact between our and other civilizations, pinning hopes on extraterrestrial civilizations for solving our eternal problems - poverty, disease, death, overpopulation of the Earth and others.
On Earth itself, contacts between differenthuman civilizations in the past have often given impetus to the development of trade, economy and culture. On the other hand, quite often peoples at a lower stage of development were either enslaved or destroyed altogether.
And although it can be assumed that some leveldevelopment presupposes an unacceptable military resolution of contradictions, this option cannot be completely ruled out. In any case, the influence of more advanced civilizations is so great that it often leads to the degradation and oblivion of their own cultural heritage.
- Fundamental contact possibility
On the part of humanity, direct contact with the current level of scientific and technological progress is impossible due to the enormous interstellar distances.
Even the closest star to us (after the Sun)Proxima Centauri is located at a distance of about 40 trillion kilometers, and to reach it, even at the maximum possible speed - the speed of light, spacecraft would take about four Earth years.
At the same time, it is not at all necessary thatliving beings live in the vicinity of the closest star. The distances to other stars are tens, hundreds and thousands of times greater, not to mention the distance to other galaxies.
Thus, the theoretical possibilitydirect contact is preserved only under the assumption that other civilizations possess methods of movement with superluminal speeds, although it is important to take into account that the possibility of developing similar technologies by other civilizations does not follow from our modern physical knowledge.
However, in principle it is possible to contactdistance. Attempts have already been made repeatedly to send signals into space that could be received and deciphered by extraterrestrial civilizations. The most famous of these projects is METI.
However, even if the alleged brothers inmind "will be able to receive our signal, there is a possibility that they are so different from us that they will not be able to understand it (in fact, only true" brothers in mind ", that is, aliens with a mind similar to ours, can do this).
- The Great Silence Paradox
According to modern scientific ideas,the possibility of the emergence of intelligent life exists not only on Earth: even if conditions suitable for this are quite rare, they must exist in some other stellar systems, which, given the huge number of stars in the observable part of the Universe and the long period of their existence, logically leads to the idea of many extraterrestrials civilizations.
Despite this, to date there is noscientific confirmation of the actual existence of extraterrestrial civilizations. The contradiction between theoretical calculations and the absence of observations of signals and other signs of the activity of extraterrestrial civilizations creates the so-called paradox of the “Great Silence of the Universe,” first formulated by Enrico Fermi in the form of a question: “Well, where are they in this case?” There are various explanations for this paradox, but none one of them is not generally accepted.
How to search for extraterrestrial civilizations?
The search for extraterrestrial intelligence is organized indirection of detection of possible manifestations and traces of the activities of extraterrestrial civilizations. So, since 1971, the SETI project has been working, within the framework of which scientists are trying to detect the activity of extraterrestrial civilizations in the radio range. The SETI project has a public distribution in the form of the SETI @ Home program.
Exoplanet discoveries that have become especiallynumerous with the advent of specialized space telescopes such as Kepler, including the Planet Hunters crowdsourcing project to search for such planets in its database, have also become promising in terms of searching for extraterrestrial life and civilizations on exoplanets located in the habitable zone.
- The formula for calculating extraterrestrial civilizations
A small group of researchers fromCaltech, NASA's Jet Propulsion Laboratory and Santiago High School have developed an updated version of an old equation to calculate the likely existence of extraterrestrial civilizations.
In the new work, the researchers expandedresearch carried out by Frank Drake back in 1961. He and his colleagues developed an equation (now known as the Drake equation) to calculate the probability of the existence of extraterrestrial civilizations - given everything that was known about space and astronomical objects at the time.
The researchers took into account variables such as the number of supposed exoplanets and star systems, as well as how many of them might support life.
In this new work, the researchers tookattention all new factors and added something else that was not taken into account in 1961 - the likelihood of the emergence of other extraterrestrial civilizations, and then their inadvertent destruction. For example, humans emit greenhouse gases into the atmosphere, and this will lead to the fact that the Earth can no longer support life.
- Finding Earth-like planets
University of British Columbia staffassessed the planets of the Milky Way that are similar to Earth. There were about six billion of them. To be similar to Earth, a planet would have to be roughly similar in size, have a rocky surface, and be close to a G-type star.
It must also orbit in habitable zones — the range of distances from a star that could contain liquid water and possibly life.
As a result, researchers have counted about six billion planets that are similar in characteristics to Earth or close to its counterparts.
- Transit method
Taking advantage of transit method, experts measurea change in the brightness of a star's radiation as a planet passes across its visible disk. By measuring the depth and duration of the star's "darkening" the planet's radius can be determined.
One of the drawbacks is that for such measurements, the planet's orbit must coincide with the observer's point of view. More than 2700 planets have been discovered by the transit method.
- Search for signals from extraterrestrial civilizations
This method was implemented by the project SETI Project - the general name for projects and activities to search for extraterrestrial civilizations and possible contact with them.
There are two approaches to the search for extraterrestrial intelligence:
- Look for signals from extraterrestrial civilizations. Relying on the fact that fellows in reason will also seek contact. There are three main problems with this approach: what to look for, how to look and where to look.
- Send a so-called "ready signal".Relying on the fact that someone will look for this signal. The main problems of this approach are actually similar to the problem of the first approach, with the exception of minor technical problems.
One approach is expressed in the NASA-fundedprogram for listening to electromagnetic signals of artificial origin - on the assumption that any technically advanced civilization should come to the creation of systems of radio-television or radar signals - the same as on Earth.
The earliest electromagnetic signals on Earthcould by now have spread in all directions over a distance of almost 100 light years. Attempts to isolate alien signals directed to the Earth have so far been unsuccessful.
- Emissions
According to a new study from NASA,An extraterrestrial technologically advanced civilization can be detected by air pollution. In this case, scientists call the main signature nitrogen dioxide.
A possible sign of life (biosignature) could bebe a combination of gases such as oxygen and methane. Likewise, the presence of technologies can be determined by nitrogen dioxide, which is a byproduct of combustion in industrial processes.
Another possible sign of the existenceextraterrestrial civilization may contain chlorofluorocarbons (CFCs), which are also powerful greenhouse gases suitable for terraforming. CFCs are not produced by living organisms, but they are produced through very specific processes.
Scientists have modeled that they canDoes nitrogen dioxide pollution create a signal that can be detected by existing and planned telescopes. This substance is capable of absorbing certain wavelengths of light reflected from the planet.
It turned out that if an extraterrestrial civilizationproduces as much nitrogen dioxide as humanity currently produces, it could be detected 30 light years away within 400 hours of observation using one of the space telescopes planned for launch .
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