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 there was never an effective resistance movement. Particular attention is given to military resistance figures such as Claus von Stauffenberg, Ludwig Beck, Erwin von Witzleben, Günther von Kluge, Erich Hoepner, Hans Oster and Friedrich Olbricht. This underlines the modern German military doctrine, which holds that military officers have a moral duty which goes beyond the blind obedience of orders, and that those officers who plotted to kill Hitler were not traitors but heroes. The same point is made about other Germans who went into exile and assisted the Allied war effort against Germany, such as Marlene Dietrich. The museum also