Avi Loeb and the Interstellar Lottery [Hackaday]

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Except for rare occasions, I don’t play the lottery. Like many of you, I consider state-run lotteries to be a tax paid only by people who can’t do math. That’s kind of arrogant coming from a guy who chose to go into biology rather than engineering specifically because he’s bad at math, but I know enough to know that the odds are never in your favor, and that I’d rather spend my money on just about anything else.

But I’m beginning to get the feeling that, unlike myself and many others, Harvard professor Avi Loeb just might be a fan of playing the lottery. That’s not meant as a dig. Far from it. In fact, I readily concede that a physicist with an endowed chair at Harvard working in astrophysics knows a lot more about math than I do. But given his recent news splashes where he waxes on about the possibility that Earth has been treated to both near misses and direct hits from interstellar visitors, I’m beginning to think that maybe I’m looking at the lottery backward.

Odd Odds

Whenever someone challenges me on my “tax on the innumerate” position — and here I risk exposing my poor math skills — I explain my position thus: to express the 1 in 300 million odds of winning Powerball as a decimal you have to write down an awful lot of zeroes before you start writing any other numbers. To my mind, a number with eight zeroes after the decimal point is indistinguishable from zero, which makes me confident that it’s essentially impossible to win the lottery. QED.

“But,” the lottery lover inevitably cries. “That number may be small, but it is definitely NOT zero! Somebody has to win, and it might as well be me.” While it’s demonstrably false that “someone has to win” — plenty of lottery drawings result in no winners — the photos of people posing with oversized checks prove that people do win. That’s sort of confounding to me, because if my position that 0.0000000033 is the same as zero were correct, nobody would ever win. Checkmate, disbeliever.

But what does the lottery have to do with Avi Loeb? In case you don’t know, Avi Loeb is a plasma physicist by training, whose former gig before moving to the astronomy department at Harvard was at the Institute for Advanced Study in Princeton — you know, the place where Einstein used to work. He’s authored more than a thousand papers and eight books; the guy is clearly no slouch in the science department.

And yet he has a habit of making statements about extraterrestrial life and technological civilizations that a lot of other scientists seem to chafe at, seeing them as sensational and attention-seeking. The criticism is understandable from an “extraordinary claims require extraordinary evidence” standpoint. When ‘Oumuamua streaked through the inner solar system in 2017, Loeb speculated that the chunk of cosmic debris could be a space probe from an extrasolar civilization, one designed to pick up signals from smaller probes sent to Earth at an earlier time, and that the smaller probes may be related to unidentified aerial phenomena (UAP).

Interstellar Coal Ash

More recently, Loeb and his colleagues mounted an expedition to the Pacific Ocean off Papua New Guinea to the impact site of a probable interstellar meteor, dubbed IM1, and recovered bits of it from the ocean floor. Isotopic analysis of the spherules revealed that some contained iron isotopes in different ratios than those found in the inner solar system, and some are older than the solar system itself, both of which support the meteor’s extrasolar origin. This is hardly conclusive, though; there’s evidence that the spherules are just coal fly ash from coal-fired steam vessels, but then again, Loeb’s further analysis of standard coal fly ash samples says they’re not.

Loeb doesn’t seem to directly state that the IM1 was a technological artifact from an extraterrestrial civilization, at least not that I could find — although he does a lot of interviews, so it’s quite likely he has. Regardless, the implication is that he thinks both IM1 and ‘Oumuamua are such objects, and that they justify a serious investigation into the nature of interstellar objects, to which end he co-founded the Galileo Project, an international search for physical evidence of extraterrestrial technical civilizations. And this is where we get to the cosmic lottery I think Avi Loeb is playing.

In a 2023 paper that gives an overview of the Galileo Project, Loeb and project co-founder Frank Laukien argue that the chance of finding a technological civilization at roughly the same level of development as ours in our neck of the galactic woods is pretty small, about one part in 100 million, which is the ratio between the age of our scientific society and the age of the oldest stars in our galaxy. So looking for technological signatures of an extant civilization is probably a fool’s errand, but it’s three times more likely than winning Powerball.

Five In a Billion (or Four)

What if a civilization like ours developed much earlier than we did? It’s possible that at some point in their development, they got the urge to explore their part of the galaxy and figured out how to fling stuff out into space, maybe zipping by the other planets of their system on their way into the void. It’s impossible to argue that such a thing couldn’t happen, since we’ve done it five times so far: both Pioneer probes, two Voyagers, and New Horizons, which isn’t in interstellar space yet but is on its way.

And here’s the important part: it only took our planet four billion years to evolve life that could manage the trick of sending stuff into interstellar space. The Milky Way is roughly 13.6 billion years old, so that means that if we assume the same rate of development, there’ve been over four full cycles of development scattered over perhaps 400 billion stars and at least that many planets. If only a small fraction of those planets got the interstellar itch and developed the means to scratch it, then the galaxy may be positively teeming with technological artifacts from long-dead civilizations. After all, our tiny little Voyager probes will be almost a tenth of the distance to the Andromeda galaxy in another four billion years, assuming they don’t run into anything on the way. If humanity could figure out how to amplify its footprint so dramatically in just two cycles of technological development, imagine what else is out there.

This is the galactic lottery I think Avi Loeb is playing. He knows that if we did it, then someone else probably did too, and he thinks the odds of finding evidence of that are very much in our favor if we just bother to look in the right place. As they say with the real lottery, “You can’t win if you don’t play,” and with a jackpot as big as this, Avi Loeb seems willing to buy tickets to the galactic lottery like crazy.