We are so fascinated by the idea of space visitors that we are attracted to these unfocused UFO videos, where you can see a flying saucer, which turns out to be a dish hung by a thread, a balloon, or simply special effects. Most of them can be proven as false and a few make us doubt. The possibility that it is true captures our imagination but, is it possible that there is life on other planets?
In 1961, radio astronomer Frank Drake set out to calculate the possibility of other civilizations exist. In each galaxy a star is formed each year, in which we live has between 100 thousand and 400 billion stars, according to Drake's estimates, only half of those stars could have planets capable of developing life and 1 of every 100 of them. those planets develop intelligent life. Of that fraction, only 1% of these intelligent species could communicate by radio waves.
Drake estimated that a civilization could use this technology for 10 thousand years. Then there would be between 1,000 and 100 million civilizations and we would have to detect 10 civilizations each year alone in our galaxy. Of course, the results of the Drake equation depend on parameters that are only conjectures, as we do not know much about the data, we guess them.
There could be thousands of civilizations in the Milky Way, or only one: ours. But, surely you know, the universe is tremendously big. It is estimated that there are 500 billion galaxies in the observable universe (dozens more, dozens less). Imagine the possibilities!
The astrophysicist Evgenya Shkolnik, goes so far as to affirm that the question is not whether there are other civilizations, but when we will find them. His reasoning is that every time we find an object or phenomenon, we will most certainly discover more.
If there is life on this safe planet there is life in others. For example, the first planet outside the solar system was discovered in the 90s. Two decades later, with the help of telescopes such as Kepler, we have confirmed nearly 5,000 planets and in the year 2020 the James Webb telescope will be put into orbit. Increase the list exponentially.
That question is called the "Fermi Paradox". Enrico Fermi asked himself: "Where are you all?"
Some possible answers are:
That there are really no extraterrestrial civilizations.
If there are, but they do not have enough technology.
They do have technology, but those civilizations have used it to destroy themselves
same with wars, or destroying their environment (as we could destroy ours).
Perhaps the most powerful civilizations have destroyed the others.
It may be that we are simply too far away from them to communicate.
Maybe extraterrestrials are too rare. How about if your language is so slow or so fast, that for us it's just noise; and if they communicate using technologies that we do not know about.
They prefer not to communicate, maybe if they can call us, but they do not want to contact us: they could consider us dangerous or like animals they do not want to bother.
Maybe they are already here, but hidden.
Everyone listens and nobody speaks: it may be that all civilizations are looking for signals from others, but they are not transmitting. Like us, Earthlings are not sending signals for the purpose of contacting aliens, but we are listening. The SETI project uses radio telescopes like ears, which use the radio signals of the cosmos and collaborate with volunteers from all over the world who lend their computers to process the data and look for patterns that could be messages.
Evgenya Shkolnik is confident that if we found extraterrestrial life, differences between less significant humans would return and we would be more aware of our collective unity.
Acronyms:
UFO: Unidentified Flying Objects.
SETI: Search for Extraterrestrial Intelligence.
@jlmol7