One of the most debated topics of classical physics is the concept of inertia, which, according to Newton, is an inherent attribute, devoid of any external influence. Newton, in spite of realising the problems associated with the idea of absolute space, had assumed its existence to describe motion relative to it. In spite of the success of Newtonian mechanics on the local scale, Leibnitz and later Bishop Berkley were among the vociferous critics of the notion of absolute space claiming it to be metaphysical. However, it was Ernst Mach who, rejecting the concept of absolute space, alternatively introduced the notion that all motions are described relative to a fixed frame as defined by the universe at large, which essentially is the matter distribution outside the body referred to. Interpreting in the Newtonian language, Mach defined inertia of a body as due to its interaction with the rest of the universe, which, in essence, creates the fixed frame of reference for defining motion.