Phew – research done with some hefty computer processing power and observations made with advanced radio astronomy telescopes indicate we can all chill out: advanced civilizations are unlikely to attack us any time soon!
“In my view, we can all sleep safely in our beds tonight – an alien invasion doesn’t seem at all likely,” says Professor Michael Garrett, the General and Scientific Director at ASTRON, the Netherlands Institute for Radio Astronomy.
In fact, Prof. Garrett says advanced alien civilizations are very rare or entirely absent from the local Universe.
With support from other academic institutions and a research grant from IBM’s Faculty Innovation program, Garrett has been working with sensitive new radio telescopes that detect the waste heat that’s expected to be a signature of advanced alien civilizations.
Having harnessed enormous energies, the thinking goes, advanced civilizations (so-called Kardashev Type III civilizations) will saturate a section of the infrared spectrum due to their emission of significant waste heat.
Yikes! In other words, pollution is one tell-tale sign of civilization. So too communication using radio transmissions – something else our civilization is pretty good at.
So for more than 50 years, a measurement scale of resource usage and radiation emission proposed by Russian astronomer Nikolai Kardashev has been in place to help assess any extraterrestrial civilization, from Type 0 (the most basic technology a civilization might be capable of) to Type IV (in which beings use the resources of the entire universe)
In other words, as we wait for The Force to be with us, Earth has been classified only as 0.724.
Garrett has made detailed radio measurements of several of the very best galactic candidates for advanced civilization, but he’s come up empty. The majority of such systems emit low radiation levels best explained by natural astrophysical processes – not giant hydro generating stations.
While some weak emissions have been detected out there, evidence suggests that they are not indications of heat from alien factories but more likely from magnetic radiation interacting with dust as part of star formation.
Scientists, cosmologists and even home computer users have long searched for extraterrestrial intelligent life in the galaxy, such as with the SETI Project, knowing that any signs will be very rare.
And the search for extraterrestrial intelligence received a huge boost earlier this year when Russian investor Yuri Milner and scientist, author and physicist Stephen Hawking announced a new $100 million fund behind their Breakthrough Initiative, and its call to not only listen for intelligent aliens, but to talk to them by designing a digital message that can be transmitted from Earth.
Now, Garrett’s new analysis suggests that’s probably wishful thinking, because other civilizations basically don’t exist in our neighbourhood.
Professor Garrett is still looking at a few candidate galaxies that lie off of the astrophysical correlation: “Some of these systems definitely demand further investigation but those already studied in detail turn out to have a natural astrophysical explanation too. It’s very likely that the remaining systems also fall into this category but of course it’s worth checking just in case!
(His research and findings are presented in the science journal Astronomy and Astrophysics 2015, A&A, 581, L5; Application of the Mid-IR/Radio correlation to the Ĝ sample and the search of advanced civilizations.)
“It’s a bit worrying that Type III civilizations don’t seem to exist,” he continued. “It’s not what we would predict from the physical laws that explain so well the rest of the physical universe. We’re missing an important part of the jigsaw puzzle here. Perhaps advanced civilizations are so energy efficient that they produce very low waste heat emission products – our current understanding of physics makes that a difficult thing to do. What’s important is to keep on searching for the signatures of extraterrestrial intelligence until we fully understand just what is going on.”
One of the reasons researchers are unable to detect any other advanced civilizations or signs of intelligent life elsewhere in the universe – we may in fact be first!
As science writer Arthur C. Clarke once noted, “In either case the idea is quite staggering.”