Are There Events in the Galaxy Without Us? Astronomers Have An Annoying New Fermi Paradox Solution

The Fermi conundrum has a solution according to a recent study, but as usual, you won’t like it.

Here is a brief explanation of the Fermi Paradox in case you are unfamiliar with it: Why hasn’t anyone contacted us yet given the great likelihood that extraterrestrial life exists elsewhere in the universe (considering the size of space and the fact that we continually discovering planets with habitable zones)? If there are so many alien civilizations, some of which may be much more evolved than our own due to how long the cosmos has existed, surely at least one of them would send out a probe or be actively attempting to colonize the galaxy. If that’s the case, why haven’t we found them?

 

Astrophysicist Michael Hart’s theory on the Fermi Paradox was acknowledged in a recent pre-print publication posted on Arxiv.com. In his essay “An Explanation for Absence of Extraterrestrials on Earth,” Hart makes the case that, given enough time and effort, a civilisation could conquer the whole cosmos.

“Assume we eventually send explorers to each of the 100 stars that are closest to us. (They are all 20 light-years or closer to the Sun.) These colonies all have the capacity to someday launch their own voyages, colonize other colonies, and so on “Hart penned. “The frontier of space exploration would then be roughly on the surface of a sphere whose radius was expanding at a rate of 0.10c, assuming there was no break in travel between missions. The majority of our galaxy would be covered at such speed in about 650,000 years. The amount of time required to traverse the Galaxy will roughly double if we assume that the intervals between voyages are of the same order as the length of a single expedition. We can see that, excluding the possibility that they started their space exploration fewer than 2 million years ago, any other advanced civilizations in our galaxy would have had plenty of time to reach us.”

Given that our galaxy is around 13.6 billion years old and if this is even remotely accurate, it is perplexing that we have not discovered any evidence of extraterrestrial civilizations. In fact, the study makes the case that the lack of extraterrestrial life elsewhere may be seen as proof that there is none on Earth. If so, Hart opined, it would necessitate a social justification for why they failed to populate the galaxy despite having sufficient opportunity to do so. Hart stated that this is “strong proof that we are the first civilization in the cosmos” unless a persuasive alternative can be produced and until we have greater knowledge about planetary formation and other variables.

In a recent publication, astrobiologists Thomas J. Fauchez and Jacob Haqq-Misra offer an alternative explanation: we have been missed because we have the wrong kind of sun. The team agrees with Hart that any answer to the Fermi Paradox must address sociocultural theories for why extraterrestrials have not colonized the galaxy, such as their realization that unrestricted development is unsustainable or their perception that our region of the galaxy is unattractive.

They point out that aliens may want to colonize more of the galaxy for a variety of reasons, including to learn more about how life develops. They also contend that some of the most alluring locations for alien settlement would be those that can support life, which may be shown by the presence of life there.

They write in their report, “Although it is conceivable that long-lived technological civilizations do not colonize the galaxy, it also remains conceivable that such civilizations pursue galactic settlement to preserve their longevity.” But why would a civilization from another planet colonize the galaxy but not the solar system?

In order to optimize their lifetime in the galaxy, they propose that a growing civilisation will preferentially settle on low-mass K- or M-dwarf systems while avoiding higher-mass stars.

A G-dwarf star, like our own sun, produces the majority of its energy through the fusion of hydrogen and helium. Hydrogen-burning K-dwarfs are said to have a larger “sweet area” for habitable planets. Compared to G-dwarfs like our own, K-dwarfs and more numerous M-dwarfs can sustain a habitable environment for a far longer period of time.

Given the lengths of space travel and the resources needed to populate a new solar system, any species looking for a place to call home might give priority to longevity.

In order to determine how long it would take for a sophisticated civilisation to colonize every K-dwarf system, M-dwarf system, and G-dwarf system, the researchers examined a number of scenarios. They calculate that it would take an intelligent civilisation (assuming there were only one of them) around 2 billion years to spread itself out over all low-mass stars, taking into account time to wait till suitable systems grew closer (K and M dwarfs).

Given that scientists have not discovered any evidence of extraterrestrial life on Earth, the team says that “we can dismiss scenarios in which all G-dwarf stars would have been settled by now,” but “the possibility remains open that a Galactic Club exists across all K-dwarf or M-dwarf stars.”

The team claims that as a result, K-dwarfs may be the ideal subject for investigations into the bio- and technological indications of extraterrestrial life. But because they are bigger, it is harder to detect planets around these stars.

The “galactic club” might exist, be thriving across the galaxy, and be exceedingly hard to find.