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Newtonian Absolute Space
Newtonian Absolute Space
When Newton proposed his axioms describing fundamental laws of physics, he insisted on the necessity of absolute space to a completed theory of mechanics. Absolute space can be best described as not-relationally-dependent space. Newton purports that there is something more to space than just being a vessel to conceptualize positional differences between specific bodies; he claims that there is some objective truth to space -- that spatial differences are not dependent upon the matter contained within space. In his Principia, he states that the difference of relational and absolute space becomes manifest in the consideration of place, velocity, and acceleration. These considerations serve to metaphysically establish absolute space in themselves. However, Newton attempts to support the existence experimentally in his famous \'bucket experiment\'. Through an explication of his reasoning and an analysis of his motivation, I intend to show that Newton\'s notion of space is, at best, incomplete.
Newton describes the difference between absolute and relative space in the scholium to definition eight in the Principia: "Absolute space...without relation to anything external, remains similar and immovable. Relative space is some movable dimension or measure of the absolute spaces" (152). His first relevant explication in the scholium is of place. Place is that which a body occupies in space. Absolute place differs from relative place in that it requires no relationship to any other body to be determined; it is determined by the construct of absolute space itself. Absolute motion, then, is the translation of a body from one absolute position to another. In the same trend, absolute velocity is constant absolute motion in time, and absolute acceleration is a change in absolute velocity in time.
With that clearly laid out, Newton has explicitly shown how absolute space is conceptually applied to mechanics. The validity of absolute space in itself still remains in question. These definitions of absolute mechanics are, in fact, used retroactively to validate the existence of absolute space. In using discussions of absolute place, velocity, and acceleration, Newton\'s proponents hope to show that there is a difference between these and their relational counterparts. There is an inherent flaw, though, in arguing for an independent, self-evident difference between absolute and relational in considering place or velocity. However, acceleration, as considered in the bucket experiment, shows promise.
The difference in absolute versus relational place is mere semantics; instead of being defined by making reference to another body, absolute place is determined by making reference to the unsubstantiated concept of absolute space. The question can be asked: What if the universe were to be moved four inches that way? Such a shift would be entirely undetectable, because there would be no shift from any point of reference, save a place in a presupposed absolute space. Only after accepting absolute space does absolute position make sense. Claiming theoretical superiority would be entirely based upon preconceived bias.
Absolute velocity is equally indiscernible from relational velocity. Velocity of a body can only be determined in reference to something. In common perception, I determine the velocity of a body by reference to another. In absolute space though, that velocity, considered in the absolute sense, might have a different magnitude. Newton\'s example of a passenger on a ship roughly runs: A man standing still on a ship moving at a constant velocity can be said to be in absolute motion, though he is in relative rest to the ship. An observer not on the ship is able to see that the man is in motion. Theoretically, it would be an observer, aware of absolute space in itself, that would be able to determine the man\'s true motion (as it is known by Newton). However, there is no such observer, save maybe God, with such an awareness, and thus absolute velocity is indiscernible. It requires a pre-established absolute point of reference to be determined.
True motion is a technical term that Newton employs. The existence of true motion, he thinks, directly lends to the existence of absolute space. Newton distinguishes absolute and relative motions by "the forces impressed upon bodies to generate motion" (156). True motion of a body is motion that occurs as a result of a force imparted directly on that body; relative motion can occur as a result of peripheral forces causing motion in the referential bodies.
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Classical mechanics, Physical quantities, Theory of relativity, Kinematics, Mechanics, Absolute time and space, Inertial frame of reference, Rest, Inertia, Space, Mass, Acceleration
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