Last week NASA’s independent study team released its highly anticipated report on UFOs. A couple of takeaways: First, the term “UFO” has been replaced in fed-speak by “UAP” (unidentified anomalous phenomena). Second, no hard evidence has emerged demonstrating an extra-terrestrial origin for UAPs, but, third, there is much that remains unexplained.
Believers in aliens are undeterred. Earlier this summer, former military intelligence officer David Grusch had made sensational claims in a congressional hearing that the U.S. government is concealing the fact that they are in possession of a “non-human spacecraft.” The NASA director himself, Bill Nelson, holds that it is likely that intelligent life exists in other corners of the universe, given the staggering number of all the stars which likely have planets with water and moderate temperatures.
A famous conversation took place in 1950 amongst a group of top scientists at Los Alamos (think: Manhattan Project) over lunch. They had been chatting about the recent UFO reports and the possibility of faster-than-light travel. Suddenly Enrico Fermi blurted out something like, “But where is everybody?”
His point was that if (as many scientists believe) there is a reasonable chance that technically-advanced life-forms can evolve on other planets, then given the number of stars (~ 300 million) in our Milky Way galaxy and the time it has existed, it should have been all colonized many times over by now. Interstellar distances are large, but 13 billion years is a long time. Earth should have received multiple visits from aliens. Yet, there is no evidence that this has occurred, not even one old alien probe circling the Sun. This apparent discrepancy is known as the Fermi paradox.
A variety of explanations have been advanced to explain it. To keep this post short, I will just list a few of these factors, pulled from a Wikipedia article:
Extraterrestrial life is rare or non-existent
Those who think that intelligent extraterrestrial life is (nearly) impossible argue that the conditions needed for the evolution of life—or at least the evolution of biological complexity—are rare or even unique to Earth.
It is possible that even if complex life is common, intelligence (and consequently civilizations) is not.
Periodic extinction by natural events [e.g., asteroid impacts or gamma ray bursts]
Intelligent alien species have not developed advanced technologies [ e.g., if most planets which contain water are totally covered by water, many planets may harbor intelligent aquatic creatures like our dolphins and whales, but they would be unlikely to develop starship technology].
It is the nature of intelligent life to destroy itself [Sigh]
It is the nature of intelligent life to destroy other technically-advanced species [A prudent strategy to minimize threats; the result being a reduction in the number of starship civilizations].
And there are many other explanations proposed, including the “zoo hypothesis,” i.e., alien life intentionally avoids communication with Earth to allow for natural evolution and sociocultural development, and avoiding interplanetary contamination, similar to people observing animals at a zoo.
As a chemical engineer and amateur reader of the literature on the origins of life, I’d put my money on the first factor. We have reasonable evidence for tracing the evolution of today’s complex life-forms back to the original cells, but I think the odds for spontaneous generation of those RNA/DNA-replicating cells are infinitesimally low. Hopeful biochemists wave their hands like windmills proposing pathways for life to arise from non-living chemicals, but I have not seen anything that seems to pass the sniff test. It is a long way from a chemical soup to a self-replicating complex system. I would be surprised to find bacteria, much less star-travelling aliens, on many other planets in the galaxy.
Maybe that’s just me. But Joy Buchanan’s recent poll of authors on this blog suggest that we are collectively a skeptical lot.
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