S-Curve Deceleration

S-curve deceleration describes the third phase of technology adoption, following slow initial uptake (emergence) and rapid middle growth (expansion). The deceleration occurs when the technology approaches the limits of its addressable market, encounters binding physical or economic constraints, or faces competition from superior alternatives. The curve's mathematical form—a logistic function or similar sigmoid—is not imposed by theory but observed empirically across virtually every technology adoption Smil and others have documented: radio, television, automobiles, personal computers, mobile phones, internet access, renewable energy. In every case, the steep middle section—the period of exponential-appearing growth—gave way to deceleration as the easy adopters were exhausted, infrastructure constraints asserted themselves, or the technology matured into a stable, saturating presence. AI adoption is currently in the steep middle section, generating growth rates that feel exponential and that extrapolate, if sustained, to absurd endpoints (every human using AI for every task within a decade). Smil's framework predicts the curve will bend, not because AI is inadequate but because no exponential growth in a physical system can