A recent profile in Astronomy focused on Abraham Loeb (pictured) a Harvard astronomer who is convinced that closed minds are a key barrier to our finding extraterrestrials. Statistically, he thinks, they must be out there somewhere:

About 25 billion stars, roughly one-quarter of those that reside in the Milky Way, lie in a habitable zone. He rounds that down to an even 10 billion to keep the calculations simple. “And then there are about a trillion galaxies like the Milky Way,” he says, “which means there are about 1022 [10 billion trillion] planets in the observable universe that could potentially host life as we know it.” In other words, searches for extraterrestrial life have barely scratched the surface. “As in other areas of exploratory science,” Loeb says, “we should investigate thoroughly before making sweeping pronouncements.”

Steve Nadis, “Why haven’t we found alien life yet? Blame our closed minds” at Astronomy

A prolific thinker, he has, along with collaborators, come up with a number of new ideas about where and how to look, and what to look for. For example, he thinks, based on astronomical calculations, that life is more likely to evolve in the distant future than now. He also uses intriguing forensic approaches to the search for extraterrestrials:

In 2014, Loeb and two collaborators, Henry Lin and Gonzalo Gonzalez Abad, decided to flip the switch: Instead of looking for signs of life, they suggested looking for signs of death, or at least serious contamination. “Anthropogenic pollution could be used as a novel biosignature for intelligent life,” wrote the Harvard team, which proposed looking for two chlorofluorocarbon (CFC) gases, tetrafluoromethane and trichlorofluoromethane, that can survive tens of thousands of years and cannot be synthesized by known natural processes.

Steve Nadis, “Why haven’t we found alien life yet? Blame our closed minds” at Astronomy

But then he has also identified as evidence of alien activity phenomena that other astronomers attribute to natural causes. Consider the fast radio bursts, short, powerful blasts of radio waves from space, first detected in 2017, for example:

Lingam and Loeb offered a provocative solution to the puzzle: Maybe some of the FRBs are artificial. If that were the case, what would be the purpose of such incredibly powerful bursts? In a 2017 paper in Astrophysical Journal Letters, Lingam and Loeb raise two possibilities: It could be a beacon to broadcast the presence of an alien civilization, which they deem “rather implausible.” Or, it could power large spaceships tugged by even larger (in area, not in mass) light sails. “The optimal frequency for powering the light sail is shown to be similar to the detected FRB frequencies,” they write — a fact that, when combined with other technical arguments, could “lend some credence to the possibility that FRBs might be artificial in origin.”

Naysayers might dismiss this, insisting that “extraordinary claims require extraordinary evidence,” Loeb notes. “I say that they require evidence, but why should they be held to a higher plane? We should not automatically dismiss explanations just because they seem exotic to some people.”

Steve Nadis, “Why haven’t we found alien life yet? Blame our closed minds” at Astronomy

Let’s come back to the naysayers in a moment. Recently, the bursts have been identified as coming from magnetars (highly magnetic neutron stars), not extraterrestrials. (An artist’s impression is pictured.)

Loeb also achieved considerable public prominence with his conclusion, published in Astrophysical Journal Letters in 2018, that a space object discovered in 2017, Oumuamua, was a “lightsail of artificial origin,” that is an extraterrestrial spacecraft:

Is the interstellar object known as “‘Oumuamua” a sign of extraterrestrial life? Avi Loeb, chair of Harvard’s Astronomy Department, isn’t surprised that his idea has drawn skepticism. All the same, he notes, progress begins with an open mind.

“This is how science works,” said Loeb. “We make a conjecture … and if someone else advances another explanation, we will compare notes and the next time we see an object of this type we will hopefully be able to tell the difference. That’s the process by which science makes progress.”

Peter Reuell, “Harvard researchers see alien potential in mysterious object” at The Harvard Gazette

But in July 2019, an international astronomy team reported in Nature Astronomy that “the observations are consistent with a purely natural origin for ‘Oumuamua.”

The skeptical astronomers admitted, however, that it’s not clear just what Oumuamua is:

“We put together a strong team of experts in various different areas of work on ‘Oumuamua. This cross-pollination led to the first comprehensive analysis and the best big-picture summary to date of what we know about the object,” Knight explained. “We tend to assume that the physical processes we observe here, close to home, are universal. And we haven’t yet seen anything like ‘Oumuamua in our solar system. This thing is weird and admittedly hard to explain, but that doesn’t exclude other natural phenomena that could explain it.”

University of Maryland, “‘Oumuamua is not an alien spacecraft: study” at Phys.org

But the team was unwilling to conclude that Oumuamua is evidence of ET. Meanwhile, in 2020, another team has found evidence that it is molecular hydrogen ice, a conclusion Loeb disputes.

Now, about those naysayers. What strikes an observer of the whole business is this: The talk about extraordinary claims requiring extraordinary evidence—or otherwise—misses the point. There is no evidence. We have not found even a single fossil bacterium on a single planet other than Earth. All claims for evidence of intelligent extraterrestrials, whether from Harvard or UFO News, are disputed. All of them, even from Harvard, are murky and iffy.

The closest parallel to this kind of evidence base is research into ghosts (paranormal research). But that sort of research is not usually defended in popular science venues; it is treated with polite scorn and skepticism at best.

Simply put, we cannot prove that either extraterrestrials or ghosts do not exist. That’s because it is very difficult to prove a negative.

What’s really happening is more like this: People who have a fully naturalist worldview (nature is all there is) can believe that there are extraterrestrial aliens but not that there are ghosts. Thus, the absence of reliable evidence for extraterrestrials creates a need for elaborate explanations for why we haven’t seen them yet. The absence of reliable evidence for ghosts is treated, by contrast, as the natural outcome of their non-existence.

The trouble is, in neither case does the philosophical preference itself amount to anything resembling evidence. It is a preference, period.

Here at Mind Matters News, we cover science fiction and other thoughts about extraterrestrials because they reflect the nature of human intelligence. Even if it should turn out that no extraterrestrials have ever existed, they are still a powerful testimony to the human imagination.

Here is one hypothesis as to why we do not see aliens (a number of others are linked at that post):

The aliens exist—but evolved into virtual reality at a nanoscale. That’s the Transcension Hypothesis, the latest in our series on science fiction hypotheses as to why we don’t see extraterrestrials. On this view, after a Singularity the ETs become virtual intelligences, exploring inner space at an undetectably small scale.

See also: Tales of an invented god