Friction friction and wear in so-called self-lubricating materials. Fluid friction occurs between fluid layers that are moving relative to each other. This internal resistance to flow is named "viscosity". In everyday terms, the viscosity of a fluid is described as its "thickness". Thus, water is "thin", having a lower viscosity, while honey is "thick", having a higher viscosity. The less viscous the fluid, the greater its ease of deformation or movement. All real fluids (except superfluids) offer some resistance to shearing and therefore are viscous. For teaching and explanatory purposes it is helpful to use the concept of an inviscid fluid
From each according to his ability, to each according to his needs Marx's terminology), the Soviet Union adapted the formula as: "From each according to his ability, to each according to his work (labour investment)". While liberation theology has sought to interpret the Christian call for justice in a way that is in harmony with this Marxist dictum, many have noted that Jesus' teaching in the "Parable of the Talents" (Matthew 25:14–30) affirms only "TO each according to his ability" (Matt. 25:15), and not "FROM each according to his ability". From each according to his ability, to each according to his needs "From each according to his ability, to each according to