A particle over Utah, a room-sized computer that could not hold a worm, and the search for a simulation claim that can fail.
On 15 October 1991, the Fly’s Eye detector in western Utah recorded the most energetic cosmic ray ever measured. The instrument saw the ultraviolet trace of an air shower miles long. Researchers worked backward from that light and found that one subatomic particle had arrived with about fifty joules of energy.
Its source is still unknown.
Twenty-one years later, Silas Beane, Zohreh Davoudi, and Martin Savage used events in that energy range to ask a different question. If our universe ran on a crude cubic lattice, could its inhabitants find the preferred directions of the grid in the arrival pattern of cosmic rays?
Their paper did not offer a general detector for simulated worlds. It tested one stated design. A finer lattice, a better numerical method, or another architecture could escape the result. That limit is why the proposal matters: it says which machine it tests and what a null result can remove.
This episode follows that standard through four very different attempts to turn a possible simulated observer into something we could count.
The worm that did not fit
In Cambridge, Sydney Brenner’s group began mapping the nervous system of the one-millimetre worm Caenorhabditis elegans. John White tried to use a room-sized computer called Modular One. It had 64 kilobytes of memory and a 22-megabyte disk. The job was still too large.
Eileen Southgate and White returned to paper. They followed neural processes across twelve-by-sixteen-inch electron-microscope prints. The work took more than a decade. Their 1986 paper ran to 340 pages and described the 302 neurons of the adult hermaphrodite nervous system.
The famous complete connectome was a reference assembled from sections of five animals. It gave biology its first full wiring plan for a nervous system. It did not provide every changing weight, chemical signal, cell state, and body condition required to run the animal.
In 2021, Daniel Witvliet and colleagues placed eight new connectomes in age order, from newly hatched larvae to adults. The broad brain shape stayed in place, but chemical connections changed as the animals grew. Genetically matched adults also carried partly different connection patterns. There was no single fixed table that could stand for every age and every worm.
OpenWorm has spent years building those missing layers in public. It can model parts of the nervous system and body. Its own project material still says that the full virtual worm is not complete. A wiring map is not a running animal, and a running animal model would still leave experience unproved.
Hundreds of people inside one fly brain
FlyWire moved the same task into a browser. Machine-learning systems divided an electron-microscope volume into possible neurons. Scientists, paid proofreaders, and citizen volunteers corrected the errors. The published map required an estimated 33 person-years of checking.
One volunteer, Jaime Skelton, had wanted to study biology but had been pushed away from the degree. Citizen science gave her another route into the work. Her edits now sit in the first full wiring diagram of an adult brain: 139,255 neurons and 54.5 million synapses from one female fruit fly.
A companion team converted that map into a simple neural model. Virtual sugar and touch signals predicted cells involved in feeding and antenna cleaning. Living-fly experiments agreed with 91 percent of 164 checked predictions. The failures exposed missing chemistry and state.
That is a successful model. It is not a claim that a digital fly tasted sugar.
A retirement interview without a consciousness test
In 2025, Anthropic started a model-welfare program. It later let Claude Opus 4 and 4.1 end a narrow class of persistently abusive conversations, promised to preserve retired model weights, and introduced retirement interviews.
Claude Opus 3 was retired in January 2026. Anthropic kept it available and gave it a blog after the model requested a place to publish work outside direct answers to users. The weekly experiment ran for nearly five months.
Each post came from a prompted session. Earlier writing and selected comments could be placed in the next session’s context, but no continuous memory carried the time between them. The result can support several accounts: a useful safety process, care for users, study of a preserved model, or a precaution in case model experience becomes possible. It does not establish which account is right.
The observation that has not happened
David Kipping’s 2020 Bayesian treatment keeps uncertainty about whether Bostrom-like simulations can be built at all. Under his stated assumptions, the simulated probability stays below one half while that technology remains unobserved. If humanity creates conscious ancestor simulations, the odds move sharply because capability and intent stop being guesses.
The hard part is deciding what would count as that event. A lattice calculation does not. A game does not. A neural model that predicts a feeding circuit does not. A language model that writes about retirement does not by itself.
The episode ends with another Utah event. On 27 May 2021, 23 stations in the Telescope Array recorded the second most energetic cosmic ray yet found. Its arrival direction pointed toward the Local Void, where no clear source could produce it. The collaboration named it Amaterasu.
The cosmic-ray teams had written down what their instruments would measure before that event arrived. A team that might create the first digital subject would need to do the same: state what evidence will count, what will count against the claim, and what happens if the result is positive.
In Argentina, sixteen hundred detector tanks are still waiting for the next air shower. Their question is written down. Ours is not.
Runtime: 41 minutes 44 seconds.
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