Fluid dynamics is a sub-discipline of fluid mechanics that describes the flow of fluids—liquids and gases. Fluid dynamics underpins our understanding of a huge number of phenomena in geophysics and astrophysics The foundational axioms of fluid dynamics are the conservation laws, specifically, conservation of mass, conservation of linear momentum, and conservation of energy (also known as the First Law of Thermodynamics). These are based on classical mechanics and are modified in quantum mechanics and general relativity. In the TANK EXPERIMENR series, the CARDIAC / The heart is subjected to experiments, some suspending it into the brain dynamics.