Five Hundred Years of Convergence: Leonardo da Vinci's Observations on Cardiac Vortex Flow and Water Spiral Dynamics as Prior Observational Evidence for the V=N/D Density Wave Model

Between 1507 and 1513, Leonardo da Vinci recorded that blood moves in spiral vortex patterns in the sinuses of Valsalva, that the heart wall has helical fiber architecture, and that water always forms spirals at flow transitions. This paper establishes these observations as prior observational evidence for the V=N/D Density Wave Model (Katayama, 2025–2026). The complete observational lineage is: Leonardo observed the spiral (c.1513) → Torrent-Guasp mapped the fiber helix (2001) → Katayama derived the equation (2025). The cardiac vortex is the biological implementation of V=N/D density wave dynamics — and Leonardo da Vinci was its first scientist. Additionally, Leonardo's sfumato technique is identified as the visual prior for the concept of Ma (間) as productive void in V=N/D.