Scale-Time Theory (STT): The Geometry of Scale-Space is a research manuscript proposing a foundations-first framework in which 4D spacetime emerges from a more primitive 2D topological “scale-plane” governed by a single conserved Noether charge (“scale-flux”, k). A rotating topological dipole Source at the puncture of the scale-plane sustains two opposite-polarity carrier beams whose universal radial slowdown and rotational imprint generate spiral crowding that culminates at a unique Present Scale Ring (PSR). At the PSR, the spiral carrier terminates in a single symmetry-breaking / single global fusion scale that produces two families of radially propagating residues (opposite polarity). Observable physics begins only at this fusion scale; the post-PSR universe is entirely residue physics (no subsequent global equalization rings or cascades). The PSR defines a master readout clock (two readout triggers per cycle) and a discrete processing depth (default Nw = 8), yielding a natural 16-slot phase/layer architecture. Our observed sector corresponds to one 8-slot half-cycle; the conjugate sector is interaction-invisible due to phase-sector separation, but remains gravity/latency-active via a sector-blind channel. In STT, gravitational phenomena arise not from spacetime curvature but from a path-complexity / latency field that modulates local proper time and reproduces weak-field GR phenomenology (e.g., via an effective refractive index). The readout light speed is PSR-fixed (derived in terms of k and PSR radius), and the quantum–classical transition is treated as a sampling/oversampling threshold effect within a single sampling-theoretic framework.