Hardness Hardness Hardness is a measure of the resistance to localized plastic deformation induced by either mechanical indentation or abrasion. Some materials (e.g. metals) are harder than others (e.g. plastics, wood). Macroscopic hardness is generally characterized by strong intermolecular bonds, but the behavior of solid materials under force is complex; therefore, there are different measurements of hardness: "scratch hardness", "indentation hardness", and "rebound hardness". Hardness is dependent on ductility, elastic stiffness, plasticity, strain, strength, toughness, viscoelasticity, and viscosity. Common examples of hard matter are ceramics, concrete, certain metals, and superhard materials, which can be contrasted with soft matter. There are three
Janka Bryl Janka Bryl Janka (Yanka) Bryl (, August 4, 1917 – July 25, 2006) was a Belarusian writer best known for his short stories. He was one of the older generation of Soviet writers who had begun their literary careers in Stalin's time but received a new lease on life in the late 1950s along with such contemporaries as Ivan Shamiakin and Ivan Melezh. His father was a railway worker. In 1922, his family returned to their hometown of Zagorje, which was then in Poland. He was unable to complete his education, due to financial difficulties. In 1939, he was drafted