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
German resistance to Nazism Group Centre created what appeared to a viable structure for a new effort at organising a coup. Bock's dismissal did not weaken Tresckow's position. In fact he soon enticed Bock's successor, General Hans von Kluge, at least part-way to supporting the resistance cause. Tresckow even brought Goerdeler, leader of the civilian resistance, to Army Group Centre to meet Kluge – an extremely dangerous tactic. The entry of the Soviet Union into the war had certain consequences for the civilian resistance. During the period of the Nazi–Soviet Pact, the KPD's only objective inside Germany was to keep itself in existence: it