Is there anybody out there? The human has been asking this intriguing and exciting question since he is aware of himself. Will there be other civilizations beyond ours? And, more importantly, will they be smart enough to communicate with us?
A very prominent figure on this issue is Frank Drake, who is currently a professor emeritus at the SETI institute (an acronym for Search for Extra Terrestrial Intelligence or ‘search for intelligent life’). Drake developed his famous equation in the 1960s to calculate how many intelligent civilizations there would be in the universe. And the worst case scenario, considering that there are between two and four hundred billion stars in the Milky Way, was that the probability of finding an intelligent civilization communicating with the outside is 0.00000003%. A number that seems small, but it is absolutely brutal, we are talking about up to 10 detectable civilizations only in our galaxy.
Now, a new team of researchers triples Drake’s numbers with a study calculating that there could be more than 30 intelligent civilizations in the Milky Way .
How long does it take for an intelligent and technological civilization to prosper?
Obtaining good estimates of the number of possible extraterrestrial civilizations has always been very difficult. There are estimates ranging from zero to billions of them. The study, led by the University of Nottingham and published in The Astrophysical Journal , has taken an innovative approach to this problem.
Using the assumption that intelligent life forms on other planets in a similar way as it does on Earth, the researchers have obtained an estimate of the number of communicating intelligent civilizations within our own galaxy, the Milky Way. They calculate that there could be more than 30 intelligent civilizations actively communicating in our local galaxy.
The classical method for estimating the number of intelligent civilizations is based on making guesses about values related to life, so opinions on these matters vary quite substantially. However, the new study simplifies these assumptions using new data, providing an estimate that tries to be more robust. Nottingham University Astrophysics Professor Christopher Conselice, who led the research, explains: “There should be at least a few dozen active civilizations in our galaxy, under the assumption that it takes 5 billion years for them to develop. form intelligent life on other planets, such as on Earth. The idea is to look at evolution, but on a cosmic scale. We call this calculation the Copernican Astrobiological Limit ”.
The Copernican Astrobiological Limit is that intelligent life is formed in less than 5 billion years, similar to what happened on Earth, where a civilization with the ability to communicate was formed after four and a half billion years.
But, in addition, research shows that the number of civilizations largely depends on how long they actively send signals of their existence into space, such as radio transmissions from satellites, television, etc. If other technological civilizations last as long as ours, which is currently 100 years old, then there will be between 30 and 36 active intelligent technical civilizations throughout our galaxy.
However, the average distance of these civilizations would be 17,000 light years away, making detection and communication very difficult with our current technology.
Another possibility is that we are the only civilization within our galaxy, an option that is equally or more terrifying. Will we ever be able to contact our galactic neighbors, if they are there? Why haven’t we done it yet? We may never get to answer these, not just scientific, but existential questions.
