We’re five billion years into the life of Sol, our beloved G-type main-sequence star, with four billion or so to go. Sol is middle-aged, you might say. Just over the hill. We feed on her continuous stream of photons.
My closest neighbor shoots a neurotransmitter into my root, and I feel she needs a little more glucose, a bit more sunlight. I rustle my solar-leaf panels, a small flex of myosin. It allows her a brighter patch. I have enough for now—she’ll share later if I ask.
I live with my kin on one small mote of a network of tightly-packed solar satellites. We spin round Sol. The satellites hang like the bioluminescent organs of a simple creature in the deep, dark depths of Earth’s ocean. But we are far from the third planet, the cradle. On our way here, there were days of miracle and years of tumult.
We are strange pumps exchanging order for entropy. In the ancient past of our kind of life, plant cells engulfed the cyanobacteria, enlisting them to turn sunlight into sugar and life. Animal cells incorporated an ancestor of alphaproteobacteria inside their membranes to become mitochondria. Branches of the tree of life wove in and out, especially among the bacteria and archaea. The superorganism of promiscuous genomes shares nucleic acids freely. They give templates for resisting harsh conditions, for drought and heat resistance, for surviving methicillin and vancomycin, for digesting rock and detritus.
Our transition wasn’t unprecedented, then. We repeated a step the plants took long, long ago. But for the first time, it was by design and not by strange evolutionary accident. When we could no longer tolerate the consumption of our fellow organisms on the little blue planet, the time came to make our own food. We created enough misery as secondary consumers, carnivores, omnivores, heterotrophs. Enough. We decided to be parasites no longer.
It took centuries of unwinding our chemical complexity, and a few biotechnology revolutions. The first photosynthesizing mice were a breakthrough, followed by the first photosynthesizing primates. When the processes were refined and then perfected, the first humans became autotrophs, too. We absorb the photons of Sol and convert them into wellbeing years, utils, hedons—call digesting sunlight into the exquisite pleasure of existing what you will.
Meanwhile, the most ambitious project humans have ever undertaken began: the Dyson Swarm, the solar satellites one astronomical unit from Sol. We aimed to make use of the vast majority of the 384.6 yottawatts which pour from our sun.
My cells, blend of siliceous and carbonaceous life, breathe in photons, breathe out glucose. Breathe in carbon dioxide, breathe out oxygen. Breathe in glucose, breathe out heat. Breathe in electrons, breathe out ATP. Breathe in ATP, breathe out every other molecule and action we need to exist. Breathe in electricity, breathe out neurotransmitter.
It was a multigenerational project which had weak precedent in the building of the Great Wall, the Roman aqueducts, the towers of the Sagrada Familia, Turkey’s grand Basilica Cistern, the International Space Station, and the interstellar spore ships. Of course the Swarm dwarfed these centuries-long endeavors. It took ordering our social systems and straightening our priorities. Easier said than done, when you’re coordinating a Nash equilibria with billions of actors. But given enough time, and incremental improvements in incentives to cooperate, we managed it.
We grew together into the solar panels of our Dyson satellite. From afar, it might look like we converged on the form of the ancient organisms known as trees. We communicate chemically with hormones, pheromones, neural connections, and electric interfaces powered by the satellite. These ancient technologies—chloroplast and solar cell—blend as we evolve.
The sphere of satellite islands allows many types of social organization, a diversity of governance systems and organisms on each microcosm. The differences are apparent in the wild artworks we spin off into the galaxy. These creations examine our challenges as we developed this configuration, the gains of cooperation, and our affection for one another.
We send probes and sentinels into interstellar space searching for our peers, of which we have found none. Among all the water worlds, gaseous clouds passing as planets, the rocky and cratered orbs we scoured, all were empty. It was at once a tragedy—like a miscarriage or a sibling never born—and a blessing. We know now that the transition from inanimate to life was the hard step, not the development of multicellularity, or the development of intelligence, or the annihilation from advanced technologies. So we are glad, but cosmically lonely nonetheless.
Nikolai Kardashev proposed a scale to classify the success of a civilization. We passed type I, which sees the capture of all sunlight hitting the home planet, a while back. Type II captures all the energy of Sol, while type III captures all the wattage of the galaxy. Types IV and V follow. So here we are, a humble 1.87 on the Kardashev scale. We are at once our ancestors’ wildest dreams, incarnate, and just a spore of what we might become.
The fresh photons raise goosebumps down my outstretched limbs, a ripple of pleasure, as I metabolize them into delicious ATP. My ancestors must have enjoyed sunbathing, even when the warmth didn’t feed them, because I can feel it’s an old joy, like gazing into the coals.
One day the lack of thermodynamic free energy will make our metabolic processes impossible—there will be no more entropy to cast into the cosmic dark. Until then, there is light on our solar-leaf panels to be harvested and affection to be shared.