Sunday SciKu | Please Like Me

This week, researchers at NYU released a study mapping the behavior of social media users onto that of rats in a Skinner box. They found it a perfect match.

As you probably know, B.F. Skinner developed the operant conditioning chamber as a way to study animal learning. In the classic setup, a rat can push a lever in order to receive a food reward, but the box is designed so that the lever only works in the presence of some other stimuli. So the rat can learn that it’s only worth pushing the lever when a light is on, for example.

The study here showed that our behavior on social media follows the same reward learning pattern—we organize our posting and commenting here based on the dopaminergic gratification of receiving “likes.” If anyone has watched The Social Dilemma or listened to Tristan Harris, this should be no surprise.

I’m curious to hear if it matches your personal experience, though, because I feel like it’s missing something, at least for me. I, too, feel like I’ve been conditioned by unconscious forces to impulsively scroll through Facebook, but it doesn’t seem to me like this kind of feedback is the drive. In fact, I find that I don’t really care about feedback at all. Maybe it’s because I’m very low in trait agreeableness.

The reward for me flipping through my news feed is mental stimulation. I can physically feel myself hunting for interesting information—it’s a search for something new to learn. Most posts don’t offer anything interesting, but often enough a post does, probably in a perfectly addictive ratio, and I’m compulsively hunting for that.

I do seek “likes,” but that feels like a fully conscious, goal-oriented behavior. Either I’m sharing something that I think would help people to know, or for work I’m sharing poems that enrich the human spirit—and I know post engagement funds reach within the algorithms of the attention economy—so I want “likes.” But I don’t feel like I’m being conditioned by likes. I’m conditioned by curiosity. Would you say the same thing? I realize I’m an outlier in a lot of ways, and it’s hard to know what’s normal.

So what is your experience with social media? Do you feel like you’re seeking the positive reward of community response, or are you seeking the stimulation of new information?

Anyway, here is this Sunday’s sciku. Originally it was a little gentler, but I’m not pulling any punches (or levers) …


rats at the dump
scavenging daily
for likes


Sunday SciKu | Overkill

For 20+ years, I’ve found the nonsense of the overkill hypothesis maddening. The idea is that humans are such efficient, warlike creatures that we arrive on new continents and murder everything we come across. The Neanderthals in Europe and the Diprotodons in Australia 42,000 years ago. The North American mammoths and mastodons 12,500 years ago. It’s the most obvious scientific farce I’ve ever heard, and yet for decades it’s remained the mainstream explanation for these recent extinction events. Really, this is nothing but the projection of our contemporary fears and guilts into the past, based on flimsy circumstantial evidence, turning science into a morality play for kindergarteners.

The obvious problem is this: Neanderthals and Diprotodons went extinct at the exact same time on opposite sides of the world. And during the Younger Dryas event 12,500 years ago, it wasn’t just mammoths that died out—it was 70% of North American megafauna, including sabretooth tigers, the American lion, 12-foot-tall short-faced bears, dire wolves, American camels, ground sloths the size of elephants, armadillos the size of Volkswagen Beetles—including even the Clovis people who were supposedly killing them. Stone age humans with spears didn’t hunt out all these massive species in a few hundred years and then kill themselves. How absurd is that? And yet most textbooks still say that’s what happened.

What actually did happen, though, is one of the deepest and most important mysteries in history. These weren’t just extinction events—big changes to the global environment were going on at the same time. There are really only two plausible explanations. There might have been a series of comet or asteroid impacts into the ice sheets and ocean, and we just haven’t found the craters. But more and more it’s looking like the real story is in the magnetic fields of the Earth and Sun, and researchers added more to the pile of evidence this week, looking at prehistoric kauri trees preserved in the bog swamps of New Zealand.

What they found was a huge increase in Carbon-14 right at the Laschamps Magnetic Excursion, 42,000 years ago. Just as the Neanderthals and Australian megafauna were going extinct, the Earth’s magnetic field was in the middle of a potential pole flip, and dropped as low as 6% of its normal strength. Carbon-14 is made in the atmosphere when cosmic rays (particles ejected from supernovae traveling near the speed of light) slam into nitrogen atoms, knocking off a proton and turning N-14 into radioactive C-14. With the Earth’s magnetic field so weak, there were way more cosmic rays reaching the atmosphere and way more C-14.

More and more we’re learning that cosmic ray penetration has a large influence on the climate. Increased cosmic rays cause a thinning of the ozone layer. They excite the silica-rich magma in volcanos, leading to increased stratospheric ash injections. They play a crucial role in cloud formation. All of these things result in rapid drops in the global temperature.

With the Earth’s magnetic field so weak, we had little shielding against solar storms and coronal mass ejections. Auroras during this time would have been global, sometimes coming close enough to the ground to create arc discharges—continent-wide lightning storms, lighting the forests on fire, creating black mat layers and nanodiamonds in the soil. They’d have seemed like fluorescent snakes spitting electricity and setting the entire world ablaze. With the ozone depleted, we had little protection from the sun’s UV light even in calm conditions. Cancer rates increased, pathogens mutated more rapidly.

This happened at the Laschamp Excursion 42,000 years ago, and it happened again during the Gothenburg Excursion 12,500 years ago. During the latter, a CME likely struck while North America was sun-facing in summer.

The picture is becoming clear: our ancestors weren’t butchers; they were survivors of a world we can’t even imagine, a Biblical apocalypse with fire in the sky, massive floods and continent-wide fires. They fled to caves to survive. They made red ochre—the pigment used in cave paintings—as primitive sunscreen, protecting them from the intense radiation. They found food and adapted as all these other animals were dying out. They lived through a catastrophe that the Neanderthals couldn’t. And that’s the only reason we’re here today, blaming them for it.

So when I see the handprints in the caves they sheltered in tens of thousands of years ago, they seem to me gestures of love and perseverance though an impossible barrier of time and trauma.


my brother’s palm
on the prison glass
red ochre


Sunday SciKu | Lovely Lemurs

Science folks save their love-related press releases for the week of Valentine’s Day, and this Sunday sciku is no exception. Monogamy is rare in mammals, with only around 4 percent of our animal class exhibiting long-term pair-bonding. Thirty years ago, researchers looked inside the brains of committed voles to see what makes love tick, and came to the conclusion that it seemed to be extra oxytocin receptors creating a kind of love circuit.

This year, researchers at Duke tried to find the same thing in a romantic species of lemurs, which are more closely related to humans—but it just plain wasn’t there. It turns out that there is no common program for love—it’s complicated, and likely arises in various species independently, as convergent evolution. So there’s not much hope of inventing Love Potion #9. We just have to keep working at it every Valentine’s Day.


great love
in the red-bellied lemurs


Sunday SciKu | Pruning

Researchers at the University of Pittsburgh have been exploring the ways SARS-CoV-2 mutates at the spike protein to evade antibodies. Coronaviruses have an error-checking system that keeps them more stable from mutation than other RNA viruses, but it turns out the proofreader doesn’t notice deletions. So there are certain segments in the spike protein sequence that can be removed without eliminating binding and replication, and we can see these same deletions again and again as we look through the genomic databases, with the virus slowly evolving to avoid our immune response. This is one of the selective pressures that makes a virus less deadly over time, as it sacrifices some of its binding affinity for immune evasion.

Last summer, our plum tree was overburdened with fruit, to the point where I had to prop up limbs to keep them from breaking, so a few weeks ago I was out there figuring out where to prune it, like some big spike protein sticking out of the earth. The combination became this week’s SciKu.


the plum tree
for lines to cut


Sunday SciKu | Fungi

This week’s sciku is inspired by Virginia Tech researchers who discovered the oldest known terrestrial fossil. The fungal filaments found deep within dolostone rocks in Southern China might help explain an ancient mystery. They date to 635 million years ago, as the climate was exiting a “snowball earth” phase. For 10 million years, an abledo/H2O feedback loop triggered runaway cooling, locking more and more water vapor as ice, until glaciers covered every continent and oceans were frozen solid over a kilometer deep.

An era of volcanism seems to have saved the planet, but how exactly the biosphere recovered relatively swiftly from such harsh conditions has always been a bit of a puzzle. One hypothesis is that fungi hidden within caves and crevices played a crucial role in life’s return to land, with their enzymes breaking up rock and tough organic matter, basically restoring a soil where plants could grow. It’s far from proven, but these fossils support that hypothesis, and if true, we really have these fungi to thank for being alive today.

I was tempted to write a bad joking senryu about how these microscopic heroes were also fun guys. But then for some reason it reminded me of the way early friends in pre-school disappear from our lives completely, yet play a major role in the development of our psyches. I remember my first crush was a girl name Sarah, and my best friend was some kid named John. I don’t remember anything else about them. In a weird way, though, those are the foundational archetypes that we build many of our relationships from for the rest of our lives. That’s even weirder to think about than a 635 million year-old fungus.


old friends
still alive in the layers
of who we are