Tribology is a multifaceted academic field that includes elements of physics, chemistry, materials, and engineering. More specifically, it requires an understanding of the interaction between microscopic irregularities on the surface of objects and friction, wear, and lubrication. These interactions are so complex that changing just one element can significantly alter the results. However, in the actual environment in which rolling bearings are used, various factors such as temperature, pressure, speed, and material properties affect them, each of which must be taken into account. Therefore, the study of tribology is extremely difficult and requires a great deal of effort and expertise to understand and apply. We are constantly challenging ourselves to find a way to express such difficult phenomena in terms of theoretical formulas.