Classical relativity explains the invariance of the speed of light by postulating a geometric structure of spacetime without physical support. In contrast, Quarkbase Cosmology restores the notion of a perfect-pressure medium—the quarkic ether—as the physical substrate from which all relativistic effects emerge. By analysing the motion of a compact quarkbase through this frictionless medium, the Lorentz factor γΨ arises naturally from the finite propagation velocity of pressure waves (cΨ). Time dilation, length contraction, and the energy–momentum relations become hydrodynamic consequences of delayed pressure restoration behind a moving source. Gravitational curvature appears as a gradient of the local propagation index nΨ(x), reproducing lensing, redshift, Shapiro delay, and Doppler effects. Relativity is thus recovered not as a geometric postulate, but as a macroscopic manifestation of the coherent dynamics of a perfectly frictionless etheric continuum.