Many people have a strong emotional attachment to the idea that there is extraterrestrial intelligence (ET) out there, along with a modest scientific basis for hope.
A matter of faith
It is a matter of faith, more than science. Here at News about the mind matters, we have covered many hypotheses as to why we have never encountered ET. There is a scientific bet, launched this year, between astrobiologist Dirk Schulze-Makuch and planetary scientist Ian Crawford that ET will be discovered within 15 years.
Where the science part comes in
A reasonable case can be made that, in a universe of our size, there must be other habitable planets, life, and some intelligent life. Fortunately, the current search for exoplanets allows us to test this idea. Some recent findings, such as the exoplanet TOI 700d, are quite interesting. Of course, research is no longer mocked as it once was.
That said, the emotional overlap—the fear of being absolutely alone forever—means that many hypotheses will continue to be offered, if only because they hold hope.
Maybe ET was here long before us and died?
An idea, discovered last month in salon, is that the ingredients for life were available in the universe long before there was life on Earth, perhaps about 380,000 years after the Big Bang. Harvard astrophysicist Avi Loeb, known for his tense theories, said SALON that
“I would say a hundred million years after the Big Bang, there were pockets of enriched material that could have led to planets and life as we know it, potentially,” Loeb said.
Carlyn Zwarenstein, “Immediately after the Big Bang, conditions were perfect for life. Did the aliens come out long before us?”, Saloni, June 15, 2024
But what about the temperature? Well, he notes, the universe was smaller and warmer back then:
“In the early universe, this temperature requirement could have been met when the universe was only fifteen million years old,” Loeb said. “And that would allow liquid water to exist, or [an adequate temperature could be achieved] when it was about seventy-five million years or so, when liquid methane or ethane would have existed as it did on Titan.
“It’s just the temperature of the whole universe because it’s filled with the radiation background, or the cosmic microwave background […] so you don’t need the object to be close to a star to reach this temperature. It would have been anywhere.”
Zwarenstein, “Getting Too Ahead of Us?”,
Loeb is not alone in this. A recent open access paper on Philosophy and Cosmology introduces the idea of cryptoterrestrial, Technologically advanced civilizations on Earth, possibly from previous geological eras, that are the origin unidentified aerial phenomena (UAP), formerly called UFO. The authors offer a number of options:
This paper has led to serious consideration of CTH as a possible explanation for UAP, while noting that it probably ranks lower than other hypotheses, such as the extraterrestrial explanation, although such calculations are difficult to quantify. To be precise, the material above actually contains four different CTHs. All would involve entities that have existed in secret throughout recent human history—and perhaps even before the appearance of Homo sapiens in some cases, such as CTH 2—but differ in the nature of the entities in question.
1. CTH1: Human Cryptoterrestrials. An ancient, technologically advanced human civilization that was destroyed long ago (eg by floods) but continued to exist in remnant form.
2. CTH2: Cryptoterrestrial hominids or theropods. A technologically advanced non-human civilization consisting of some terrestrial animal that evolved to live in secret (eg, underground), possibly a hominid, or else a species much closer to us (eg, descendants of unknown, intelligent dinosaurs).
3. CTH3: Former cryptoterrestrials or extraterrestrials. Extraterrestrials or our intertemporal descendants who “arrived” on Earth from somewhere else in the cosmos or from the human future, respectively, and went into hiding.
4. CTH4: Magical Crypto-Earths. Entities that are less like home-grown aliens and more like angels on earth, who relate to the human-inhabited world in ways that are (at least from our current perspective) less technological than magical, known in the languages European with names like fairies, elves. nymphs etc.
Lomas, Tim; Case, Brendan; Masters; Michael M. (2024). The Cryptoterrestrial Hypothesis: A Case for Scientific Openness to a Subterranean Earth Explanation for Unidentified Anomalous Phenomena. Philosophy and Cosmology. Volume 33. https://doi.org/
The authors are two sociologists from Harvard’s Human Flourishing Program and a biological anthropologist. They are probably right to worry that their ideas will not be taken seriously by planetary scientists.
The most limitless space of all
Here is my perspective as a skeptical observer trying to be sympathetic (because it would be truly terrifying to believe that we are truly alone in an impenetrable void): Fortunately, there is a space more limitless than the physical universe – and this space is the human imagination. Team ideas are best explored in good science fiction, where actual scientific concepts are used to develop an admittedly fictional idea: For example, a film based on the idea that ET once ruled but disappeared before, or with dinosaurs to have the advantage of up-to-date knowledge of palaeontology AND special effects.
What never gets old is the belief that They are there – one foot in faith, one in science, and a great future in imagination.