Space, Time, and Spacetime as Mitotic Structures in a Human Cell A Biological Reinterpretation of Spacetime Geometry and Cosmic Expansion

The Cosmology of the Living Cell postulates that the observable universe is the inner space of a single, permanently mitotically dividing human cell. Building on the correspondence shown in the author's previous work—where the Big Bang corresponds to the G2/M transition and cosmic inflation to prometaphase spindle assembly—this paper extends the framework to the fundamental concepts of space, time, and spacetime. Space is reinterpreted as the dynamic, expanding volume of the mitotic spindle apparatus and the perinuclear region. Time emerges as the precise, biologically regulated clock of the cell cycle, with the duration of mitotic phases dictating the observed cosmic timescales. Spacetime itself proves to be the geometric manifestation of microtubule dynamics and checkpoint-controlled expansion during human mitosis. Mathematical correspondences are derived between the Minkowski metric, the FLRW scale factor, proper time in general relativity, and the biophysical parameters of mitosis (microtubule polymerization rates, Cyclin-B oscillation periods, spindle volume growth). The hypothesis predicts specific deviations in high-redshift spacetime geometry and temporal evolution that are already partially visible in JWST data and will become testable with future missions (e.g., Roman, Euclid, CMB-S4). This work establishes space, time, and spacetime not as abstract physical entities, but as biologically generated structures produced by the mitotic apparatus of a human cell.