ABSTRACT
The tribology is treated from the perspective of the lubricant layers separating the two interacting surfaces. The Scientific Era consists of the spanning the nineteenth and twentieth centuries that brought about tribology’s technological revolution. The true significance of this new stage in tribology is that, from its primitive role of merely reducing friction, the function of the lubricant was discovered to be that of physically separating the mating surfaces. The most important contributor to tribology’s renaissance was the discovery of petroleum and its widespread utilization in everyday life and industry. From grease layers measured in parts of an inch, tribology has ventured into synovial films on the order of one to several microns and in elastohydrodynamic lubrication to fractions of a micron. All this has carried the tribologist in ever more intimate parts of the interface layer, where the lubricant, the surface asperities, and the chemical and molecular activities all participate in whatever the film produces in its final performance.
