Pascal's law, also known as Pascal's principle, states that when a change in pressure is applied to an enclosed fluid, that change in pressure is transmitted undiminished throughout the fluid in all directions. This principle is applicable to fluids at rest and is a fundamental concept in fluid mechanics.
Articles by others on the same topic
A pressure increment applied to a confined fluid in equilibrium is transmitted throughout it. The pressure increment is a scalar, not a force vector copied in one direction. Comparing different heights also requires the hydrostatic pressure difference. Finite-speed pressure wave propagation precedes the new equilibrium.