How could the extraterrestrials have visited Earth in the past?

The real reason that we have not found civilizations alienígenasNo look for more, we are alone in the UniversoLa terrible hypothesis as to why we never saw aliens

The Milky Way, our galaxy could be full of extraterrestrial civilizations despite the fact that up to now we have not found any. And not only that. is Some of those civilizations might have visited the Earth millions of years ago, and their traces have been erased by time.

These are some of the extraordinary conclusions of an article published last month in The Astronomical Journal by a team of researchers from NASA and the universities of Rochester, Pennsylvania, and Columbia.

The study provides a new approach to the Fermi Paradox, according to which the Universe is sufficiently old to have allowed the development of countless civilizations, in addition to our. And if so, asked the Italian scientist, in 1950, "Where is everybody?".

To Jonathan Carroll-Nellenback, first author of the article, and his colleagues, Fermi did not take into account a factor of great importance: everything in the Universe moves. And given the distances, even within our own galaxy, are enormous, the travelers from other planets could be taking advantage of these natural movements to explore just the solar systems that "put shot". In other words, a hypothetical civilisation intelligent and advanced, might be taking his time to explore the entire galaxy.

The stars (and their planets), revolve around the galactic center at different speeds and following different paths. And as you do so, notes Carroll-Nellenback, occasionally intersect, so that the aliens could simply be waiting to your destination is close enough to be able to deal with it.

Assumptions of the zoo

Up to now, numerous researchers have tried to give an answer to the Fermi paradox. And they have done so in the most varied forms: from assume that all intelligent forms of life outside of Earth are aquatic and live in the ocean depths (and do not know, therefore, space flight), to ensure that no civilization is sustainable, and ends by destroying itself before getting to master the flights interstellar. It has even been postulated the so-called "hypothesis of the zoo," according to which advanced societies of the Milky Way have decided not to contact us for the same reasons that we try not to contact, to protect them, with some indigenous people. [Ten theories about aliens].

But none of these solutions had been considered, until now, that everything in the galaxy is in continuous movement. And that in the same way that planets orbit around the stars, the stars also, with its planets in tow, orbiting the galactic center. Our Solar System, for example, completes an orbit every 230 million years.

For that reason, the study says that if there are civilizations in star systems very far apart, as happens with ours, which is located in a sparsely populated area of stars near the edge of the Milky Way, it would not be a bad idea to "shorten the trip" and wait until their orbital paths they get close enough to the new worlds habitable as to allow the sending of ships and settlers.

After, and once established in the new system, the aliens could repeat the move and wait, again, to be at an optimum distance of travel to give a new jump. And so on. In such a scenario, the alien civilizations are not it would issue no more across the galaxy, but that would wait long enough for your star is close to another that had a habitable planet.

"If that enough time out of a thousand million years," explains Carroll-Nellenback to the magazine Business Insider - then we have a solution to the Fermi paradox". According to the researcher, this would mean that the worlds livable are so scarce that it would be necessary to wait, in fact, the more time that lasts a civilization before one of them put the scope.

The spread

In their work, the scientists used numerical models able to simulate as it would be the spread of a civilization across the galaxy. To do this, they had in mind the possibilities are more varied, from the proximity of a hypothetical civilization to new star systems to the extent and the speed of their probes. At no time during the study took into account the intentions and the policy of expansion of such hypothetical cultures, a true "trap" in the that have stalled other solutions to the Fermi paradox. In the words of lewis Carroll-Nellenback, "we try to get to a model that involves the least possible amount of assumptions of sociological in character".

Even so, a good part of the problem with the modeling of the expansion galactic alien civilizations is that the researchers only were able to work with a single set of data: the our. So that, whether they wanted to or not, all of their predictions are based on the patterns of our own behavior.

however, even with that limitation, Carroll-Nellenback and her colleagues discovered that the Milky Way could be, literally, full of solar systems colonized by intelligent beings , even if you apply the most conservative estimates. If you still have not visited the Earth, says the researcher, "is because we're not close enough ". Although yes that would have been able to do so in the past.

Were you here?

According to the article in the Astronomical Journal, one of the main arguments against the idea that our planet may have been "visited" in the past is that there is no evidence, rest or proof that a record of that visit.

But our planet is 4,500 million years old, and if a civilization landed here at some point far in the future, the traces of her stay could have been erased with the time. It is even possible that the extraterrestrials have come to our world when humans already existed in him, but he decided not to visit us. To think that "expansion" and "conquest" always go hand-in-hand is a tendency, very human, and to project it to other civilizations, would be to sin of naivety. The study calls this possibility "the Aurora", in honor of the novel of the same title by Kim Stanley Robinson.

In other words, the alien civilizations are only asentarían in a fraction of the worlds livable are. And yet the number of planets colonized could be huge.

therefore, the authors of the study do not believe that we should become discouraged before the apparent silence that surrounds us. In the words of lewis Carroll-Nellenback, this silence "does not imply that we are alone. It simply means that habitable planets are probably very rare and difficult to achieve."

Date Of Update: 20 September 2019, 15:01