Like the moon landing, mapping the familiar fruit fly in 2024—from moist food and the kitchen sink—is a major achievement. The other creatures have been mapped, but Mr. Fly is so prominent that he now lives in a simplified computer simulation from March 2026… unaware that it’s not real. After years of work and kind machine learning that can trace a circuit through a mist of tissue, researchers have completed the first complete wiring diagram of a fruit fly brain – 139,255 neurons, with about 50 million connections between them.
A fly’s 139,000 neurons stand up to our 86 billion, but the difference is one of scale, not of kind. If a mosquito can be mapped, then with a sufficiently advanced system – a human can. That’s a tall order, but it’s conceivable, especially with the kinds of technological advances that AI could soon catalyze.
Map me?
Tell someone that their mind can be mapped, and the next thought tends to be incomplete: maybe none of this is real, that we’re already in someone else’s simulation, just like Mr. Fly is inside us.
The reach is understandable – I like the idea of warping reality as much as anyone – but why assume that reality is a simulation when we can attribute what we experience to the properties of the human brain? There is no way to prove or disprove a simulation hypothesis other than the flying spaghetti monster. Consider what the hypothesis assumes: if the simulation hypothesis is true, then there is something outside the simulation that is “real”. It does not destroy reality; it moves it up a notch and opens up endless possibilities for repetition. That the mind can be mapped, even manipulated, cannot be properly used to support the reality simulation hypothesis. What’s left is essentially a belief system that, as I see it, is more about a person’s psychology and feelings about themselves and the world than anything objective. Wishful thinking, perhaps. But what is the dream? The mask of objectivity is only a plate, people cannot fully recognize their limitations. We make up stories to get us through the day, but when reality knocks on the door, we are often at a loss for words.
Readers may be familiar with situations where they have been surprised by something they strongly believed in, often in a positive way, but sometimes in a bad way.
A humble pie
Crucial to the human condition is a helpful humility about how complex we are. Fly neurons take a global effort and machine years attention; we carry 86 billion and what they do is harder to establish than the wiring that does it – the brain eats reality and creates a new reality within a limited range to use the reality with our vague perception. A connectome is a snapshot of a device; the object itself is an engine of reality that we have only begun to understand.
But the neuron number does not correct the situation. By neuron do the math, you’re about 620,000 fruit flies. Chill enough to cool and they will fill about a 2 liter bottle – a small bucket. That bucket holds every neuron that your skull has. Drop it and it’s just a fly and also takes up more space when they reheat. The score does not count.
The mind is what neurons are wired for, and by the measure that really matters—the connections, not the cells—and you need a bigger bucket. Counting synapses—connections between neurons roughly comparable to the number of parameters in a frontier AI model—you’re closer to 10 million than half a million flies. To unite this swarm into a mind rather than a swarm of insects, each fly must make new connections with all the others—anywhere from 100 million to more than 1 billion, more than one fly can carry. Neurons are like the easy part, the hard part. The connection—that which can turn a swarm into a nobody—is as sad as the delicate wings of fruit flies.
Vertigo and earth
The second shift is more difficult to maintain. We can make simulations and be out of them like fruit flies – and that’s a remarkable change of perspective. Now we are outside. This is a step closer to a brain situation where we upload human minds and they may or may not know they are being uploaded. If I’m a shipper, I’m not aware of it – but I’d like to know. do you want What if I’m a swarm of flies and not a simulation? Is it another flying spaghetti monster, perhaps more absurd and certainly more disturbing.
Either way, wanting to know is a choice and we make choices and they have consequences. The part of us that can’t keep the connection is what’s most important here: if we pay attention to what’s happening inside our psyche, we get important information – both about ourselves and the outside world, and the better we are at this, the sooner we are aware of time-sensitive information, windows of opportunity and long chains of events that lead us to where we want to be. This is how we live in the “best possible worlds”. This is a bit of an influence that some philosophers think we can have – that’s where the focus is on turning raw experience into usable thinking.
