By Tim Binnall
An intriguing new paper exploring the question of why Earth has not been visited by aliens puts forward the somewhat dispiriting theory that humans may simply be too primitive to warrant attention from technologically advanced ETs. The thought-provoking concept, put forward by astrophysicist Amri Wandel, originated as an attempt an answering the famed Fermi Paradox, which observes that the universe is teeming with life, yet our planet has never been contacted by extraterrestrials. While many answers to this conundrum from scientists revolve around the possibility that life in space may actually be fairly rare, Wandel offers a different scenario wherein life may be so abundant that aliens looking to make contact with advanced civilizations may not find us all that interesting yet.
Arguing that despite being advanced beyond our wildest imagination, a hypothetical alien civilization would still have limited resources to use in their search for intelligent life in space, Wandel postulates that they "would choose planets with special properties as targets to their probes." Specifically, he suggests that the ETs might look for worlds which display a technosignature, such as radio transmissions, which would set them apart from planets that only show signs of life, since that encompasses all manner of possible critters that cannot communicate with them. " Presuming biological life is common," he writes, "Earth's biosignature would not be outstanding" to aliens observing the planet from a vast distance away.
Although our planet has developed something of a technosignature since radio broadcasting began nearly a century ago, Wandel notes that the waves emanating from our planet have only reached approximately 100 light years into space which considerably limits the number of potential alien civilizations which could have noticed that. Additionally, to a space-faring species of advanced beings, radio waves may not be particularly enticing to an alien race that could have discovered them thousands of years ago. While humanity might not qualify as intelligent life in the eyes of the ETs, there's always hope that our radio signals will eventually reach a civilization out there that is curious enough come and find us.