Thread by @catvalente

OMG I want to tell you about the coolest thing I've learned about in a hot minute! (Maybe everyone already knows about this, but it's new to me AND I LIKE LEARNING STUFF LET'S GO ON A JOURNEY OF EXPLOSIVE DISCOVERY TOGETHER)

SO. Under the precise right (or very wrong) conditions, natural deposits of uranium can develop spontaneous nuclear fission chain reactions identical to the kind we make on purpose in modern nuclear reactors.

*This has already happened at least once.* About 1.7 billion years ago in Oklo, Gabon.

How do we know a spontaneous natural nuclear fission reactor formed in Africa 1.7 billion years ago?

Well, in 1972, a bunch of French chemists were quality-testing reactor-bound ore from Gabon, and it turned out a LOT of the local uranium was already markedly depleted.

This being the Cold War, people were pretty uptight about accounting for all fissionable isotopes in any given civilian facility because big boom bad, so they needed to figure out how this could possibly have happened in a fairly new mine.

Turns out the type of depletion found in the Oklo uranium isotopes 234-36 (234 & 236 completely gone with Overachiever 235 still present but down over 40%) is exactly what happens to material left over from nuclear reactors.

So that was that, they announced their findings, and over the next many years, other sites near Oklo showed the same markers.

And here's where it gets interesting.

The Oklo reactor formed 1.7 billion years ago during the Paleoproterozoic era, when life on Earth was a loose gentlemen's club of sea algae and a few early eukaryotes.

The oxygen content of our atmosphere had only recently considered working for a living & ticked up to a perky 2%, which is not perky at all, but Our Friend Uranium can only dissolve into water with a oxygen as a catalyst. So the groundwater, freshly aerated, seeped into a uranium lode & moderated the neutrons being produced by natural nuclear fission into a self-sustained chain reaction just the way the rods & pools of a man-made reactor do.

Long story short? The Oklo reactor burned & cooled on a THREE HOUR CYCLE for HUNDREDS OF THOUSANDS OF YEARS until all the fissionable material was used up.

Concentrations of the gases produced by fission trapped in the Gabonian ore fields allow us to actually know the time intervals of the reaction cycle from 1.7 billion years ago and it's BONKERS.

30 minutes of Mega-Chernobyl-style criticality that boiled away the Super Helpful lightly-oxygenated groundwater, then, once it was gone, without a moderator to slow the excited neutrons down, the chain reaction went through 2.5 hours of cooldown until the water could seep back in & the whole thing started all over again.

FOR HUNDREDS OF THOUSANDS OF YEARS.

So to recap, 1.7 billion years ago, when life was basically just Spicy Algae, there was an open bleeding wound spreading for miles in Gabon that ooze-ploded every three hours for several hundred thousand years, hurking out radiation, intense heat, & all kinds of xenon, iodine, caesium, & barium into the air, groundwater, soil, & early photosynthetic organisms.

Now, I'm not remotely a scientist, but on reading about all this I immediately wondered if the Oklo reactors, and others, if they occurred elsewhere & we just haven't found them yet, could be a pretty significant factor in Spicy Algae mutating into Spicy Amoeba & so on all the way up to us, a Primeval Splash Park of radioctive slag interacting with a few Floaty Cell Bois, slouching toward sentience, their hour come, well, maybe, someday, if we're lucky.

So I googled it, & that was in fact the very next hypothesis made by actual smart scientists, & a very real theory about the origin of the vast biodiversity of our Mutation-Happy Planet.

So whenever you feel like everything is terrible because mostly everything is terrible, remember that we are very likely just a runaway nuclear reaction that found a way to outlive its power source, get up out of the ground, walk around the place, screw everything up, make some really beautiful art, unscrew a couple of things, screw way more up even worse, have a lot of existential crises, also sometimes become tigers or dragonflies or horseshoe crabs or bananas, get fancy enough to figure out that it's a walking, talking, feeling, anxiety-riddled nuclear meltdown still-in-progress, and yet keep on going, trying to be, in aggregate, just a little better every cycle.

It's okay to be a hot mess. It's what we came from. It's our mother and father. And it's beautiful, even as it's terrifying.

Plus, let's be honest, 30 minutes of productive criticality every three hours feels just about right these days, doesn't it?

Thank you for coming to my Ore Bed Talk!

@threadreaderapp unroll please