Worldbuilding Wednesday: Boltzmann Brains

(Hello! Near as I can manage, every Wednesday will have a post outlining some feature of the Parhelionverse, and as always I invite questions about the world, story, characters, etc. on the Tumblr blog. These posts aren’t necessary to understand the comic, but they might be handy for summarizing context. All of the posts can be found on the About page. Patreon backers can read one post into the future.)

Excerpted from the Encyclopedia Xenobiologica, v43.981.4a, slightly abridged, Ponoma Publishing House, a Yima subsidiary

While not a “living” “species” in any typical sense, no taxonomy would be complete without Boltzmann Brains. Born from stochastic particle motion, these creatures are insatiably curious about whatever strikes their fancy.

Their composition- pure thought and energy- makes them compatible with both computers and literal brains. The transition is jarring at first for all parties, but over time they can blend into a truly remarkable hybrid.(1)

Hence, their main occupation is projects too sprawling and intricate for any AI. One computer-fused Boltzmann can plot transit logistics for a small planet, or run orbital calculations for an entire fleet. Inhibitor substrates curb deviant urges, but the promise of indulging their curiosity on a grand scale means this coercion is rarely necessary.

Theoretically, a Boltzmann Brain can form anywhere. In practice, 99.9% of them- and the only ones to survive for more than an instant- are born from the Fracture, a region of spatial and temporal anomalies beyond current understanding. (See FRACTURE, p.387, Encyclopedia Xenocartologica) (2)

Surrounding the Fracture are stations to capture, stabilize, assess, and train Boltzmann Brains for commercial use. Seventy percent dissipate within ten minutes. Ninety percent of the remainder are unsuitable for reasons ranging from lack of relevant skills to violent tendencies. On average, each station yields four to seven usable Boltzmann Brains per standard year, each commanding a price on par with a Dayh luxury cruiser. Most are sold to industrial clients for typical purposes, but a few eccentrics pay vastly more for special requests.

The average lifespan of a Boltzmann, assuming no quick dissipation, is thirty-three to forty standard years. Substrates can prolong it to nearly two hundred, with AI augmentation patching up mental decay.

Biologically, they have no need to eat, and only need to rest for roughly four of every thirty hours. It is unclear how they derive energy at all, with research still ongoing. Their bodies are semi-corporeal; they can pick up and manipulate objects, but conventional weapons are rarely effective in harming them. Most species have difficulty looking directly at them, ending up nauseous from trying to process the crackling form into something understandable. Honing this into a deadly skill is not unheard of.

Boltzmann Brains have no particular dimorphism, and their lack of centralized culture has yielded no gender roles. They are genderless-by-default, but roughly ten percent take up the trappings and pronouns of a particular gender nonetheless.

Notable Boltzmann Brains:


The newest Tyrant, Basilisk is blunt, uncompromising, and offers immense scientific archives to anyone who submits to their rule. [The remainder of this entry requires 7A access.]


A syncretic folk goddess of liberation. There is no conclusive evidence of her existing as a literal being. [The remainder of this entry requires 9A-4 access.]

(1) Reports of Boltzmann brains permanently cohabiting with living beings are largely spurious and anecdotal.

(2) There are fringe theories that the entire universe is suffused with Boltzmann Brains existing on undetectably small time scales, but these can be safely discounted.)

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