Читать книгу Force and Energy; A Theory of Dynamics - Allen Grant - Страница 4
ОглавлениеPOWER.
A POWER is that which initiates or terminates, accelerates or retards, motion in one or more particles of ponderable matter or of the ethereal medium.
Power, as here understood, is thus the widest of all possible dynamical conceptions. It cannot be defined by genus and differentia, because it is itself the summum genus of dynamical science. Accordingly, it will be observed that no attempt is made above to assign it to any higher class, such as things, entities, or concepts. Nothing would be gained, for example, by saying that a power is the tendency to initiate or terminate motion: it is best described by the indefinite statement given at the head of this chapter. It is simply that which produces or destroys, increases or lessens, motion in any particle or particles of any substance whatsoever cognisable by man.
Powers are of two sorts, Forces and Energies, the differences between which will be fully set forth in subsequent chapters. Meanwhile, as a help to the provisional comprehension of the nature of Power, which can scarcely be grasped at first in the abstract terms of our formal definition, it may be mentioned that amongst the varieties of Power are such Forces as Gravitation, Cohesion, and Chemical Affinity, besides such Energies as Heat, Electricity, and Light. These expressions are here employed in their popular sense, merely as guides to the sort of concept provisionally set forward for the term Power, until the subsequent investigation has rendered possible a more rational and comprehensive notion in the mind of the reader.
