posted on 2018-01-24, 02:43authored byG. F. Vasconcelos Júnior, R. P. S. Costa, B. F. Rizzuti
In the present paper, we present operational definitions of the physical quantities distance, mass and time. Attempts to formulate a well-based operational definition of physical entities were first proposed in the end of the 19-th century by Hermann von Helmholtz and Otto Hölder. The problem consists in finding how to associate a number (the value of the entity) with a non-numerical entity (the entity itself). The paper presents a modern reading of the above mentioned authors. Paraphrasing Feynman in his classic work on path integrals, “there is a pleasure in recognizing old things from a new point of view”.