By Jake Anderson | Creative Commons | TheMindUnleashed.com
(TMU) – Few mysteries rile the imagination like the search for extraterrestrial intelligence. SETI and other groups have spent decades scanning the skies for signals from other worlds and have yet to confirm the existence of ET. While the majority of astrophysicists and astronomers believe there are almost certainly other advanced life forms out there somewhere, the science behind xenology – the study of extraterrestrial life – has been greatly limited by technological constraints.
A new study published in The Astrophysical Journal, however, argues that a reasonable estimate can be deduced by using Earth-like planets as a variable in a mathematical equation. The research concludes that there are likely 36 active ET civilizations in the Milky Way galaxy alone.
Astrophysics professor Christopher Conselice, who was chief researcher for the study, says: “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.”
First author Tom Westby explains further: “The classic method for estimating the number of intelligent civilizations relies on making guesses of values relating to life, whereby opinions about such matters vary quite substantially. Our new study simplifies these assumptions using new data, giving us a solid estimate of the number of civilizations in our Galaxy.”
Conselice adds, “The idea is looking at evolution but on a cosmic scale. We call this calculation the Astrobiological Copernican Limit.”
The classic method Westby refers to is the Drake Equation, which was a 1960s-era probabilistic argument for how to calculate the number of alien species out there.
However, despite the initial optimism, in recent decades the confounding silence from the cosmos has led some to question whether we’re alone. The Fermi Paradox uses its own probabilistic argument to question why, if life is so common in the universe, we haven’t received any messages or seen a single artifact or probe.
Explanations for the Fermi Paradox abound: 1) Alien signals are out there but we can’t decode them 2) Aliens more advanced than us have transcended physical space 3) Alien civilizations die off fairly quickly after gaining intelligence 4) Aliens have quarantined us in a kind of cosmic zoo so that they can study our development.
One of the most logical explanations – that the distance and time that must be overcome to convey a message or spaceship across the incredible gulfs of interstellar space – is touched upon by the new study. The researchers write that the average distance between civilizations is 17,000 light-years.
For context on how massive this distance really is, consider that the nearest star to Earth, Alpha Centauri, is only 4.3 light-years away. With our current fastest speeds, it would take a human probe 78,000 years to reach this star system.
The researchers also say it is exceedingly possible that these civilizations went extinct thousands of years ago.
While visiting even a nearby alien star is out of our reach for the foreseeable future, new technologies in the coming years may allow us to confirm the existence of an alien civilization.
For example, the James Webb Space Telescope, which is scheduled for deployment in the coming year or so, is so powerful it will be able to study the atmospheres of exoplanets and look for “biosignatures.” In other words, we will be able to determine if an advanced species there is using industrial technology that alters the composition of the atmosphere.
The new study also considers how the search for ET reflects on the evolution of our own species:
“Our new research suggests that searches for extraterrestrial intelligent civilizations not only reveals the existence of how life forms, but also gives us clues for how long our own civilization will last. If we find that intelligent life is common then this would reveal that our civilization could exist for much longer 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 long-term existence. By searching for extraterrestrial intelligent life — even if we find nothing — we are discovering our own future and fate.”
It’s incredible to ponder the notion of there being over 30 advanced civilizations in our galaxy. Then, when you consider that the Milky Way is just one out of hundreds of billions of galaxies in the observable universe, human comprehension begins to fail.
