The concepts and theories of modern physics / By J.B. Stallo.

  • John Stallo
Date:
1900
Catalogue details

Licence: In copyright

Credit: The concepts and theories of modern physics / By J.B. Stallo. Source: Wellcome Collection.

    239/376 (page 189)
    as phenomena ■ are concerned, consists in a mere rela- tion. This Cartesius also acknowledged ; but in deduc- ing his consequences he forgot his own definition and framed his laws of motion as though motion were some- thing real and ahsohiteP As will Lc noticed, Leibnitx here assumes, as a matter of course, that what is real is also absolute. In view of this it is hardly surprising that he, too, falls into the same inconsistency with which he charges Descartes, and, in his letters to Clarke, speaks of “absolutely immovable space” and an “ab- solutely veritable motion of bodies.” * A'ewton, in the great Scholium to the last of the “Definitions” prefixed to his l^rincipia, sharply dis- tinguishes between absolute and relative time and mo- tion. “Absolute and mathematical time,” he says,t “in itself and in its nature without relation to anything external, flows equally and is otherwise called duration ; relative, apparent and vulgar time is any sensible and extrinsic, accurate or unequal measure of duration by motion which is ordinarily taken for true time. . . . Absolute is distinguished from relative time in astron- omy by the equation of vulgar time. For the natural days, which are vulgarly taken in the measurement of time as equal, are unequal. ... It may he that there is no equable motion hy which time is accurately meas- ured P ^ “ Absolute space, in its nature without relation to anything external, always remains similar and immova- ble ; of this (absolute space) relative space is any mova- ble measure or dimension which is sensibly defined by its place in reference to bodies, and is vulgarly taken * 0pp. ed. Erdmann, pp. 766, 770. f Princ. (ed. Le Seur & Jacq.), p. 8. t L. c., p. 10. q2