There are a few questions in science for which the whole world wants to get the answer and one such question is on the existence of alien life. We have built so many telescopes, sent so many missions, studies terabytes of data but still, we don’t even have single strong evidence of the existence of extraterrestrial life.
Considering our planet, we know from the geological record that life started relatively quickly, as soon as the environment was stable enough to support it. We also know that the first multicellular organism, which eventually produced today’s technological civilization, took far longer to evolve, approximately 4 billion years which is a lot and it again took a lot of time to evolve into intelligent life like humans. So, this itself gives us an intuition that intelligence might be rare.
A new study by David Kipping, an assistant professor in the Department of Astronomy at University of Columbia provides a statistical analysis of how likely it is for intelligent life to exist beyond our planet. This new analysis uses a technique called Bayesian Inference that allows for updating the probability as we get more data.
“The rapid emergence of life and the late evolution of humanity, in the context of the timeline of evolution, are certainly suggestive,” Kipping said. “But in this study, it’s possible to actually quantify what the facts tell us.“
The study started by taking Earth and the evolution of intelligent life here as the starting point. He asked himself as in if the clock repeats what is the probability that intelligent life evolve again?
He saw that there seems four possibilities
- Life is common and so is intelligence.
- Life is common but intelligence is rare.
- Life is rare but when it happens intelligence is common
- Life is rare and intelligence is too.
Noone on the planet can certainly claim one of these possibilities but thanks to Bayesian Inference we can achieve something like betting odds.
On an Earth rerun, life will most likely emerge again at a 9:1 odds according to Bayesian Inference and it was 3:2 odds for intelligent life to emerge.
The above results are only statistical-based and can’t be guaranteed. We can’t say surely that even if we rerun the earth clock will the life form or not especially intelligent.
Anyhow, are you waiting to meet some extraterrestrial intelligence? Tell us in comments
An objective Bayesian analysis of life’s early start and our late arrival (PNAS) DOI: 10.1073/pnas.1921655117