Wired tries to defend SETI and UFOlogy. They argue that there are 3 branches of inquiry — exobiology, the search for extraterrestrial intelligence, and the study of UFOs — and each has their place in our battery of methods.

Aliens—hypothetical beings from outer space—fall into roughly three categories. They could be far-away microbes or other creatures that don’t use technology humans can detect; they could be far-away creatures that use technology earthlings can identify; or they could be creatures that have used technology to come to Earth.

Each of these categories has a different branch of research dedicated to it, and each one is probably less likely than the last to actually find something: Astrobiologists use telescopes to seek biochemical evidence of microbes on other planets. SETI scientists, on the other hand, use telescopes to look for hints of intelligent beings’ technological signatures as they beam through the cosmos. Investigating the idea that aliens have traveled here and have skimmed the air with spaceships, meanwhile, is the province of pseudoscientists. Or so the narrative goes.

The issue, the article argues, is that the boundaries of legitimate research have shifted over time and are culturally determined, not objective at all. There’s a continuum of legitimacy, and it’s entirely arbitrary that we place UFOs in pseudoscience, and don’t fund SETI, and think exobiology is valid and interesting. That is a good point, except that I think there is a solid criterion that is rooted in how we do science.

Here’s the deal: early in our training, we’re taught to keep an open mind — you use hypotheses to guide a line of research, but we must be prepared to find unexpected results and alternative explanations. We’re adapted to thinking, “My experiment to test my hypothesis should find X, but if it finds Y we’ll have to modify the hypothesis, and if the answer is Z, well, back to the drawing board, but gosh, that would be exciting.” Experiments are designed that give interesting results, and whether the results are compatible with our hypothesis or reject it are equally useful.

Exobiology fits the paradigm. We’re looking at other worlds with they hypothesis that life produces chemical signatures we can detect, and even if we don’t see them, we learn something about that alien planet. We gather data looking for biology, and if we don’t see it, we still have data on extraterrestrial chemistry. That’s the safe bet funding agencies look for, that we’ll learn something even if our preliminary hypothesis fails.

SETI doesn’t work that way. SETI is looking for specific patterns in extraterrestrial signals; they have a pre-set goal, rather than an open inquiry. Not finding a signal they are looking for is a literal failure that tells us nothing. That star isn’t transmitting anything useful? Abandon it, move on, look somewhere else. Over and over again. It also doesn’t help that all their hypotheses look like ad hoc dreck contrived to convince people that there might be someone out there, with infinitely bendable variables.

UFOlogy, on the other hand, is an extreme example of that latter phenomenon. We don’t see what we’re looking for — no little green men, no crashed spaceships — so they invent elaborate and often contradictory rationalizations. The evidence isn’t there, but they are determined to pretend that it is. It’s a kind of anti-empiricism where the accumulated data is irrelevant to the conclusion.

It’s as simple as asking, “What will we learn from doing the observation/experiment?” SETI’s answer is nothing, unless we find a one in a trillion possibility, then it’s the jackpot. UFOlogy’s answer is that they already know little green men exist, so we just have to photograph thrown pie plates until we’ve persuaded the establishment. Neither is good science.

Both SETI and UFOlogy are strongly susceptible to apophenia as well. They are trying to fit complex data to a prior expectation, so there’s a tendency to impose patterns on noise. Here’s a classic example: NASA has observed complex sand dune formations on Mars.

Cool. What causes it? These are windblown rills shaped by topography and prevailing, but changeable, winds that formed under more or less chaotic pressures, producing lines and bumps and branches.

But, if you’re looking for it, it could be a signal. Perhaps, if we ignore the physical mechanisms that made them, these dunes could be Martian handwriting. Or better yet, a Martian code.

Right. So someone, probably as a bit of lark, tried to interpret them as dots and dashes, and then translated them into Morse code (why ancient Martians would have used a code devised by a 19th century American is left as an exercise for the reader). The Martian dunes therefore announce to the universe these immortal words:

NEE NED ZB 6TNN DEIBEDH SIEFI EBEEE SSIEI ESEE SEEE !!

I’m sure that means something profound in the original Martian. Either that, or it’s a compressed recipe for cored cow rectums.

That’s the problem with SETI, though. The universe produces patterns all the time, and human brains strain to impose interpretable derivations on them — SETI will milk that for all the news and attention they can get, even if it is ultimately meaningless.

Meanwhile, UFOlogists already know that the aliens are living on Mars, and have trained Bigfoots raking the dunes to send secret messages to the fleet hovering invisibly in our atmosphere, and you ignore it at your peril, you fools.

When I walked into work this morning, I noticed something odd: all the sidewalk tiles were outlined with ragged, chalky lines. It sure was a lot of work to go to to get such a minimal, if striking effect.

The explanation was obvious (look at the top right tiles), and was clearer a little later when I came home. Melting snow and ice filled the cracks first, and then there’s a race between slow diffusion of meltwater and evaporation due to the sun, leaving precipitated salts at the leading edge of the front.

It looked cool, anyway.

I’m only a 21st century Minnesotan, by which I mean I grew up on the West coast, lived on the East coast, and only made the trek to the Midwest when I was in my 40s, in the summer of 2000. One feature of the trip across Ohio and Illinois, up through Wisconsin along Lake Michigan, and across to Minnesota and the Mississippi that grossed out my kids was the bugs — the windshield splatter, and worst of all, the black cake of insect carcasses matting the grille of our truck at the end. In the years after we arrived, there were many times our car imitated a filter feeder on summer drives, sucking in a pathetic mass of dead mosquitos and mayflies, requiring a thorough hosing out to be presentable once again. We’d also see the weather radar on the TV, showing vast clouds of insect hatches rising from the rivers and lakes.

In recent years, though, almost imperceptibly, the population of insects has declined to the point where it’s unusual and noticeable when we splatter a few bugs on a drive across the state. Apparently, we also missed the genuinely remarkable swarms that sporadically blanketed the Midwest in the 1950s.

Through the middle of the 20th century, enormous summertime swarms of Hexagenia mayflies were a common sight across many of North America’s largest waterways. The immense scale of mayfly emergences made them a natural spectacle, and reports of the aquatic insects blanketing waterfront cities regularly filled newspaper headlines. Deep drifts of mayflies rendered streets impassable until snowplows could clear and grit roadways, and the dense swarms reduced visibility and inhibited water navigation, temporarily halting river transportation.

I regret not ever seeing that spectacle, although the locals don’t seem to — while I’ve heard many stories of fierce blizzards and massive snowfalls in the “old days”, no one has regaled me with tales of deep deposits of mayfly corpses. It’s a shame, I’d like to hear about it.

These stories do at least make an anecdotal impression that there has been a steep decline in the aquatic insect population. From a time when insect swarms could shut down travel in the mid-century, to my personal experience of running into major bug densities when I first arrived in Minnesota, to now only rarely hearing about scattered clouds of mayflies rising off the lakes, it’s hard to avoid the conclusion that we have a problem here. The problem is…us.

…by 1970, these mass emergences had largely disappeared. The combination of increasing eutrophication from agricultural runoff, chronic hypoxia, hydrologic engineering, and environmental toxicity resulted in the disappearance of Hexagenia from many prominent midwestern waterways, with complete extirpation from the Western Lake Erie Basin and large segments of the Illinois, Ohio, and Mississippi Rivers. After two decades of absence, targeted efforts in conservation and environmental protection led to the eventual recovery of Hexagenia populations and recolonization of major habitats in the early 1990s.

So there was a window of time where the numbers were even lower, and what I saw in 2000 was a resurgence? I’d say, from my subjective observations, that they’re in decline again, and what we need is more hard data on insect numbers over time. That’s what we’re getting from Stepanian and others, who recently published quantitative data on the emergence of mayflies across Lake Erie and the Upper Mississippi river, making calibrated measurements using weather radar. For instance, here’s a single emergence event smothering the entire western end of Lake Erie in a single night in June of 2018.

Over two billion insects surging out of the water over the span of a few hours! That isn’t even the most impressive event: they report that a single event in Lake Erie can spawn 88 billion mayflies with a mass of over 3,000 tons; the upper reaches of the Mississippi might produce 3.25 billion insects weighing a total of 114 tons. These events represent a huge transfer of organic matter from the bottoms of lakes and streams to terrestrial environments. That’s a significant transfer of nutrients like phosphorus and sulfur to the land, and is clearly an important food source for many animals. The authors do an entertaining calculation of how many calories are in flux here.

Starting with the 104.49 calories contained in a single Hexagenia limbata, we multiply by the Lake Erie emergence (115 billion individuals) to get annual caloric content (12.016 trillion calories). We took the tree swallow (Tachycineta bicolor) as a model aerial insectivore that has been shown to rely on aquatic insect emergence for feeding fledglings during the nesting season. Dividing the total annual caloric content of the emergence (12.016 billion kcal) by the required 224 kcal to raise a nestling over the 15-d development period, we arrive at the total number of nestlings that can be supported by this food resource (53.6 million birds).

That matters! While I vaguely had the impression that mayfly numbers have declined in the 20 years I’ve lived here, that kind of loss has effects that ripple upwards through the populations of animals that live here. It’s too easy to obliviously trundle along, relieved that I’m not having to go to the car wash as often, and then at some point we notice that we’re not hearing as many songbirds, and the bats seem to be dying off, and the fishing isn’t quite as good anymore, and we finally wonder what’s going on…and it’s too late, because we didn’t stop to think that maybe life in the Midwest has been missing the tons of flying biomass that had been periodically deluging the environment with manna.

That’s one of the messages of this paper — that we have lost about half the mayfly biomass in recent decades, lost to poor management of fertilizers and excessive toxic chemicals in our most productive agricultural lands and just general neglect of wetlands. They’re measuring the disappearance of billions of insects.

It’s a slow, quiet catastrophe. We’re in the depths of winter right now, no mayflies in sight, but just yesterday I was out by our local river, the Pomme de Terre, where this is a typical view. It’s frozen over, with a foot or two of ice frosted with snow, but beneath all that is a busy ecosystem, with fish feeding on the aquatic insect larvae, and billions of mayfly larvae consuming algae and detritus, growing strong for the spring thaw and the summer breeding season, when they should leap into the air in eager swarms, filling the air with life.

But will they?

Stepanian PM, Entrekin SA, Wainwright CE, Mirkovic D, Tank JL, Kelly JF (2020) Declines in an abundant aquatic insect, the burrowing mayfly, across major North American waterways. Proc Natl Acad Sci U S A. 2020 Feb 11;117(6):2987-2992. doi: 10.1073/pnas.1913598117.