BY DR. JOEY PALU-AY DACUDAO
(Part 1)
IN 1933, Konstantin Tsiolkovsky, wrote about the now famous conundrum. To paraphrase: “If intelligent beings on the planets of the universe existed, then they would have given us some sign of their existence, or they would have visited the Earth.”
Tsiolkovsky fittingly was the founder of modern rocketry and aeronautics, the sciences that brought humanity to outer space. He must have wondered what outer space would bring to humanity.
Tsiolkovsky referred to other people that speculated on this matter, so was far from the first to think about this issue.
Then in 1950 the great scientist Enrico Fermi, on a discussion about this same topic with other fellow physicists, exclaimed in frustration: “But where is everybody?”
Since then, this conundrum has been called the Fermi paradox.
As decades passed, refinements to the paradox have been developed. They usually fall under the categories of how probable is the existence of aliens with advanced civilizations, their ability and willingness to contact us, or create artifacts, electromagnetic waves, and communications that can be detected by us and understood to have originated from intelligent beings.
Current research seems to concentrate on the search for exoplanets in habitable zones around suitable long-lived stars, and attempts at the detection of electromagnetic waves (including visible light and radio waves) that technologically advanced civilizations would emit. It would take pages to discuss these all in a detailed fashion. So, let’s just go straight to proposed solutions, and be as brief as possible about them.
The Zoo hypothesis. Earth is being avoided or isolated. This was first proposed by Tsiolkovsky himself. The intelligent aliens avoid contact with us because we are not yet ‘ready’, and so our planet, biosphere, and humanity (or other sapient species in the future) are being allowed to evolve until such time as we are ready. The theme beloved of conspiracy theorists and sci-fi fans of humanity being experimented on by aliens, the laboratory hypothesis, is a variant of this.
Sufficiently advanced alien civilizations are rare or zero. Under this category falls the Rare Earth hypothesis (conditions for an Earth-like planet, with a specific long-lived stable star, a moon to cause seasons, gas giants to draw away potential bolide impactors, a position in the galaxy far from other stars or supernovas, a geological history wherein the planet and its biosphere somehow survived extinction events which the Earth’s biosphere has, and so on, is of astronomically low probability.
Related is the Firstborn hypothesis. We are the first sentient beings that happened to have evolved, so there aren’t intelligent aliens out there to contact.
Related is The Great Filter, which should be more aptly called the Great Filters (natural phenomena that would make it unlikely for life to evolve from inanimate matter to an advanced civilization).
Related are evolutionary barriers, such as sufficiently advanced civilizations have not evolved yet, advanced civilizations that do have evolved tend to destroy themselves, advanced civilizations tend to destroy others.
There are others, mostly refinements and offshoots, but for purposes of this article, let’s examine the last one above. (To be continued)/PN
