How Everything Works on Instagram: "In his anatomical notebooks, Leonardo da Vinci observed that the human heart is “vortex-oriented,” meaning blood does not simply move in straight lines through the chambers but instead swirls in spiraling patterns. To study this, he built glass models of the heart and poured in water mixed with grass seeds to visualize the flow. What he discovered was that as blood passes through the ventricles and valves, it forms eddies and vortexes that aid circulation. Thi