Explains Physics on Instagram: "The principle of communicating vessels explains that when a single, uniform, and incompressible fluid is at rest inside connected containers, the liquid will settle at the same height in all of them, no matter their shape or size, as long as they are open to the same atmospheric pressure. . . This happens because pressure within a fluid at rest is the same at any given horizontal level. Since the surface of the liquid in each open tube is under the same atmospheri