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
Memorial to the German Resistance the German resistance in the broader sense. Historians agree that there was no united, national resistance movement in Nazi Germany at any time during Hitler's years in power (1933–45). Joachim Fest describes it as "the resistance that never was." Nevertheless, the term German Resistance ("Deutscher Widerstand") is now used to describe all elements of opposition and resistance to the Nazi Regime, including the underground networks of the Social Democrats and Communists, The White Rose, opposition activities in the Christian churches (e.g. the Confessing Church), and the resistance groups based in the civil service, intelligence organs and armed forces. The visitor