Newtonian Absolute Time vs Fluxional Time
N. Guicciardini
Abstract
In this paper, I will first very briefly recall some features of Newtonian absolute, true, and mathematical time (absolute time, for short) as defined in the Principia. What I will try to do is to explain why Newton needed to resort to the idea of absolute time in his natural philosophy, and why he introduced this concept that -as we know from Einstein’s work- must actually be rejected in contemporary physics. I will then move on to consider the characterization of time employed in the method of fluxions, what I call “fluxional time”. Again, I will underline why Newton introduced this concept in his method of fluxions. He did so about two decades before writing the Principia, in a context that is quite different from the natural philosophy of force, acceleration and gravitation that was top of the agenda for the author of the Principia.