Life as a process, not a substance — and a process can run on anything. In a computer, simple rules conjure things that flock, hunt, heal their wounds, reproduce, and evolve, with no chemistry at all. Artificial life asks whether 'alive' is about what a thing is made of, or only about what it does.
The Four Natures
each piece emerges by one of four natures
The Idea
the three-beat story
Christopher Langton named the field in the 1980s and posed its question: biology studies life-as-we-know-it, carbon and water; artificial life studies life-as-it-could-be — the abstract logic of the living, freed from its chemistry. If life is a kind of process, it should be able to run on a computer.
Craig Reynolds' 'boids' (1986) gave each simulated bird three trivial rules — steer toward neighbors, match their heading, avoid crowding — and a lifelike flock emerged, wheeling and splitting like the real thing. No bird leads; the flocking lives in the interaction. The same lesson as the ant colony and the slime mold, in pure code.
Later worlds went further: Lenia's smooth digital organisms glide, self-heal, and reproduce; Tierra and Avida let self-copying programs mutate and evolve under selection, breeding parasites and arms races no one designed. They are, by every behavior, lifelike. Whether any of it is alive is the open question the field was built to ask.
Three Rules Make a Flock
each boid follows only three local rules — steer toward neighbors, match their heading, avoid crowding — and a lifelike flock emerges, with no leader and no code for 'flock' anywhere. An illustration of Reynolds' boids, NOT a published model.
The Reckoning
the thread, and the honesty about it
Life Without Chemistry
the thread, at its far end
- The widest reach of the life-like: organisms made of information alone, doing what the living do with no molecule involved.
- >The software end of the thread — cross-linked to cellular automata — and a mirror of the whole biosphere's emergence corpus.
Strong vs Weak
the honest divide
- Weak ALife: these systems model and illuminate life. Uncontroversial and powerful.
- Strong ALife: the claim that a rich enough digital system could be genuinely, not metaphorically, alive. A real and unresolved philosophical position — flagged here as open, not asserted.
Render, Not Invent
sourced
- Summarized from the public record; John von Neumann (d. 1957), who designed the first self-reproducing automaton, is minted in memoriam; living researchers (Langton, Reynolds, Chan, Ray, Sims) are CITED, not minted.
- Emergents are systems and concepts. The interactive below is an illustration of rule-based flocking, not any specific published model.
The Roster
the cells, concepts, and pioneers as ACI .agents — each a birth certificate & a nature (11)
