0143-0807/27/5/1019
Abstract
Momentum is commonly defined as 'mass times velocity'. However, this cannot be a general definition, since it does not include other types of momentum, including macroscopic radiation momentum or the momentum of a photon. Rankine coined a general definition for energy. Is it possible to describe a corresponding definition of momentum?
'There is a part of everything which is unexplored...Even in the smallest thing there is something in it which is unknown. We must find it'.
Gustav Flaubert (1821–1880) quoted by Guy de Maupassant (1850–1893) [144].