Theorem on the Impossibility of Digital Immortality: The One-Neuron Physical Barrier to Mind Uploading

Digital immortality is densely promoted in public discourse as an impending engineering reality. This narrative is not science; it is marketing, public gaslighting, and a physical absurdity. This paper formally demonstrates that standard physics strictly forbids the exact reproduction or continuous transfer of a biological mind into a digital substrate. We prove the Theorem on the Impossibility of Digital Immortality by scaling the problem down to a single living cell. We show that no physically possible computer in our Universe can accurately predict, compute, or exactly replicate a micro-trajectory of just 100 actual spike/no-spike responses of one living neuron over one minute. A living neuron is not a deterministic logic gate; it is an open finite-temperature quantum-thermodynamic system. Tracking its exact physical trajectory requires calculating nonlinear threshold dynamics driven by stochastic molecular conformations and ion-channel gating. Attempting to continuously map even a conservative subset of these events ($10^6 ion channels at microsecond resolution for one minute) generates an exact branch-space explosion of \2^{6 \times 10^{13}}$ possible histories. This infinitely exceeds the computational threshold of the entire observable Universe (the Bekenstein and Margolus-Levitin bounds), reinforced by the absolute universal prohibition provided by the quantum no-cloning theorem. Therefore, physics makes it fundamentally impossible to digitally reproduce even 100 impulses of a single functioning biological component. Any attempt to "upload" a mind mathematically results only in the creation of a separate, independent behavioral simulacrum (an algorithmic impersonator), entirely devoid of physical or subjective continuity. "Digital immortality" is a scientifically invalid concept inherently prohibited by the local laws of thermodynamics and quantum mechanics. Plain-Language Thesis:Physics prohibits copying a living mind. You cannot exactly compute or digitally reproduce even 100 biological impulses of a single living neuron, let alone an entire brain. Therefore, "mind uploading" is not a matter of future technological progress; it is an absolute physical impossibility and a marketing myth.