36 Alien Civilizations Have Colonized the Milky Way
By: Leon Okwatch
Tags: Science Fiction, Astronomy, Space, Physics, Science

Re-thinking the Drake Equation; The Astrobiological Copernican Limit.

A new study published in the Astrophysical Journal has shifted the paradigm on the question of alien existence.

The study, conducted by researchers at the University of Nottingham, takes a fresh look at the Drake Equation. The researchers developed a new calculation called the Astrobiological Copernican Limit which is a more specific alien probability analysis than the Drake Equation.

First, some background.

The ACL draws inspiration from the famous Copernican Principle; the idea that earth does not sit at the center of the universe or is special in some way.

In the 16th Century, scientist Nikolau Copernicus proposed that the Sun is centrally located and stationary in contrast to the then currently upheld belief that the Earth was central. Austrian cosmologist Sir Herman Bondi named the principle after Copernicus in the mid-20th century.

By looking at the world through the eyes of this principle, we can remove certain blinders and preconceptions about ourselves and re-examine our relationship with the universe.

The new study centers around the Copernican principle. The study guesstimates that the number of Communicating Extraterrestrial Intelligent Life in our galaxy could be somewhere between 4 and 211, but most likely 36!

Professor of Astrophysics at the University of Nottingham, 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 intelligent life to form on other planets, as on Earth.”

The research is looking at evolution, but on a cosmic scale, hence the “Astrobiological Copernican Limit.”

Of course, the civilizations proposed by the team would be able to send radio signals out into space, which is what qualifies them as communicating.

The key difference between the ACL and the Drake equation is that it makes very simple assumptions about how life developed.

One major assumption is that life forms scientifically; that is, if the right conditions are met, then life will form.

This approach bypasses the two impossible-to-answer questions that have plagued previous calculations; “what fraction of planets in the habitable zone of a star will form life?” and “what fraction of life will evolve into intelligent life?”

These two questions are not answerable until we detect life, which still seems like a far-fetched reality.

Again, much like the Drake Equation, the ACL isn’t without its fair share of issues. We can’t accurately know the correct figures to compute, with estimates of the number of anything in the Milky Way tending to differ from source to source.

We don’t know the number of stars and exoplanets in the galaxy. So while this new method is surgical in its approach, it’s by no means definitive. We are still at the stage of trying to figure out the most precise values to compute.

There’s also the fact that we’re still not certain what caused intelligent life to evolve even on earth. The assumption that it could happen anywhere else in the universe “under the right circumstances” is incredibly far-fetched.

Additionally, the study suggested that the average distance to the nearest civilization might be about 17000 light-years, making detection and communication extremely difficult with our current technology.