Aliens exist (or maybe not?)
“The aliens exist, I want to believe!” exclaym in choir fans of The X-Files, but not only them. In favor of the existence of other alien civilizations is the law of large numbers: in a universe that could contain up to 500 billion galaxies, each containing an average of 100 billion stars, the hypothesis that in 14 billion years only on Earth has developed an advanced civilization is equal to that which the Earth was flat and the center of the universe.
ALIENS EXIST: BUT LIKE ELEMENTARY FORMS OF LIFE
The hypothesis that there may be aliens at shorter distances to the Earth is now also made by NASA, which in recent years has identified some possible “candidates” in the solar system able to host (or having hosted) elementary forms of life such as viruses or bacteria. They are Jupiter’s moons, Europa and Ganymede, that of Saturn, Titan, the dwarf planets Ceres and Pluto and the planet Mars. But of the times to confirm this hypothesis, last year Ellen Stofan, NASA’s chief scientist, said that “we will have strong indicators on the actual presence of life outside of Earth in a decade, and it is therefore likely that we will have the definitive evidence within a period of time ranging from 20 to 30 years”.
ALIENS EXIST: BUT LIVING AWAY FROM THE EARTH
So far, thanks to the Kepler space telescope, we were able to discover over 4,300 possible exoplanets (of which more than 1,100 confirmed) and it is estimated that about 11% of the total have features compatible with the development of life. Taking into account that Kepler covers just 0.28% of the sky, you understand how many potentially habitable planets exist in the universe. The problem is that those who seem more compatible with the development of life forms evolved are all at distances of hundreds if not thousands of light years from Earth; also in the case of KIC 8462852, around which Kepler has observed that something that suggest the presence of a possible “alien machine”, it is nearly 1,500 light-years away.
ALIENS EXIST: THEY WILL SAVE US FROM EXTINCTION
For some advanced alien civilizations exist, have overcome the problem of cosmic distances and are already in touch with the Earth and its inhabitants. To support it are the theoreticians of contact with ancient astronauts, but also many ufologists that quoting more or less official sources reported in recent years an “intensive surveillance” of American and Soviet nuclear activities by Ufos and possible aliens vehicles with or without a crew. Indeed according to some witnesses, the aliens would have had numerous occasions to intervene to prevent the outbreak of World War III, and that the human race was in danger of extinction. If these theories turns out to correct the aliens would prove one (or more) much more advanced civilization than that of humans, both from the technological aspect and from an ethical viewpoint.
ALIENS EXIST: BUT THEY ARE DANGEROUS
Many also fear the opposite hypothesis, i.e. that any alien civilizations will prove anything but friendly to the Earth. To give a voice to those who preach caution and suggested not to send messages at random in the cosmos is none other than the most famous living astrophysicist, Stephen Hawking, and some of his colleagues seem to have taken it very seriously, as astronomers David Kipping and Alex Teachey of the Columbia University of New York who proposed to use laser technology to get some kind of “invisibility” cloak and so conceal the presence of life on Earth to any observers scattered aliens in the universe.
ALIENS EXIST OR NOT?
You are still not convinced that aliens exist? You are in good company. In 1950 the famous physicist Enrico Fermi, conversing with some colleagues from the Los Alamos laboratories, including Edward Teller, after hearing the arguments of one or the other merely he asked: “if indeed the universe teeming with life, where is everybody?” Over the decades, many have tried to give an answer to this question, more or less convincingly, but a basic truth remains (unless alien conspiracy theorists have reason): To date we have not been able to receive any alien signal, except perhaps the “wow” signal. Thus the hypothesis that the only highly developed civilization of the universe, at least in the last tens of thousand years, might be Earth although unlikely could eventually be the correct one.