The Spacedepth model proposes an integrated paradigm for understanding the physical and energetic properties of ancient megalithic structures as active, resonance-based instruments rather than purely symbolic or funerary monuments. At the center of this inquiry is the premise that civilizations such as those of the Giza Plateau, Mesopotamia, and Pre-Pottery Neolithic Anatolia utilized a sophisticated knowledge of materials science, acoustics, and geometry to harness environmental energy—a knowledge set that finds striking parallels in contemporary developments in photonics, orbital radar tomography, and advanced materials engineering. This report analyzes the theoretical foundations of the Spacedepth model, explores the recent discoveries made through Synthetic Aperture Radar (SAR) and muon tomography, and identifies the causal relationships between ancient architectural intent and modern technological imperatives in solar energy, acoustic manipulation, and gravity research.