Is anyone out there? This is a question that researchers from the University of Nottingham are trying to answer in a new study where they estimate that more than 30 technological civilizations would currently inhabit somewhere in the Milky Way.
In recent times, advances in exobiology and greater mental openness of the establishment Scientist has tipped the scales towards the possibility that the universe is full of life, looking almost ridiculous at this point to suggest that humans are the only intelligent beings. However, obtaining a good estimate of the number of possible civilizations out there has remained defiant in simple equations.
Now, a new study led by the University of Nottingham and published in The Astrophysical Journal, has taken a new approach to arrive at a figure. Using the assumption that intelligent life forms on other planets in a similar way as it does on Earth, these scientists have obtained the estimate of the number of technological civilizations within our galaxy.
They estimate that there could be around 30 intelligent civilizations capable of communicating and sending signals.
“There should be at least a few dozen active civilizations in our galaxy under the assumption that it takes 5 billion years for intelligent life to form on other planets, such as on Earth,” says the professor of astrophysics at the University of Nottingham Christopher Conselice, who led the investigation. “The idea is to look at evolution, but on a cosmic scale. We call this calculation the Copernicus Astrobiological Limit.”
On the other hand, the first author Tom Westby explains: “The classic method to estimate the number of intelligent civilizations is based on making conjectures of the values related to life, reason why the opinions on these matters vary substantially. Our new study simplifies these assumptions using new data, giving us a solid basis for estimating the number of civilizations in our galaxy.”
36 civilizations
The two Astrobiological Limits of Copernicus are that intelligent life forms in less than 5 billion years, or after approximately 5 billion years — similar to that of Earth, where a communicating civilization formed after 4.5 billion years— . In the solid criterion, according to which a metal content equal to that of the Sun is needed (the Sun is relatively rich in metals), we calculate that there should be around 36 active civilizations in our Galaxy”.
According to the latest astronomical calculations, the disk of our galaxy would have a diameter of up to 150,000 light years.
Research shows that the number of civilizations largely depends on how long they actively send signals of their existence into space, such as radio broadcasts from satellites, television, etc. If other tech civilizations last as long as ours, which is currently 100 years old, then there will be around 36 smart tech civilizations going on across our galaxy.
However, the average distance of these civilizations could be up to 17,000 light years, making detection and communication very difficult using our present technology. It is also possible that we are the only civilization currently within our galaxy, unless the survival times of civilizations like ours are long.
Clues to our own civilization
“Our new research suggests that the search for intelligent extraterrestrial civilizations not only reveals the existence of how life is formed, but also hints at how long our own civilization will last. If we discover that intelligent life is common, then this would be to reveal that our civilization could exist for much more than a few hundred years, alternatively, if we find that there are no active civilizations in our galaxy, it is a bad sign for our own existence to long term ”, says Conselice.
“By seeking extraterrestrial intelligent life, even if we find nothing, we are discovering our own future and destiny,” he concludes.
Source: University of Nottingham.
