We examine the foundational assumption shared by quantum computing, classical analogcomputing, billiard-ball computing, and biological computing (soldier crabs): that continuous physical variables can be controlled with sucient precision to perform useful computation. We introduce concrete error-correction schemes for billiard-ball systems (BBEC) and crab-based systems (CEC), demonstrate that their failure modes are structurally identical to those facing quantum error correction (QEC), and show that the reasons we immediately recognize BBEC and CEC as unworkable apply with equal force to QEC at scale. We present a formal framework for comparing precision requirements across paradigms, address the linearity objection by showing that decoherence reintroduces eective chaos, and catalog 30 years of unfullled milestones inquantum computing. We conclude that the precision requirements for useful quantum computation are, by all available experimental evidence, physically unachievable, and that the quantum computing program rests on the same unfounded assumption as the billiard-ball computer: that continuous variables in physical matter can be controlled with arbitrary precision.