Adhesion at friction and wear

Our understanding of the surrounding world, from friction to the origin of life, depends on how we imagine the contact interaction of condensed bodies. What are the forces acting in contact with solids? Do they attract (adhesive) or repel (dehesive)? Theory and research at the atomic-molecular level have shown that the force are adhesive, but everyday experiences cast doubt on this conclusion. This article addresses this issue by considering the mistakes made in experimental and theoretical tribology and surface physics. Taking into account the theories of hybridization and dehybridization of electron orbitals and valence bonds, the views on the structure of the surfaces of condensed bodies and the force arising during contact interaction are revised. The influence of van der Waals, hydrogen, covalent, metallic, and ionic bonds on the properties of lubricants is evaluated. The contours of the dehesive-deformation theory of friction and wear are also outlined.