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Originally introduced by Sir Isaac Newton in ''Philosophiæ Naturalis Principia Mathematica'', the concepts of absolute time and space provided a theoretical foundation that facilitated Newtonian mechanics.〔Mughal, Muhammad Aurang Zeb. 2009. (Time, absolute ). Birx, H. James (ed.), ''Encyclopedia of Time: Science, Philosophy, Theology, and Culture'', Vol. 3. Thousand Oaks, CA: Sage, pp. 1254-1255.〕 According to Newton, absolute time and space respectively are independent aspects of objective reality:〔In ''Philosophiae Naturalis Principia Mathematica'' See the ''Principia'' on line at (Andrew Motte Translation )〕 Absolute, true and mathematical time, of itself, and from its own nature flows equably without regard to anything external, and by another name is called duration: relative, apparent and common time, is some sensible and external (whether accurate or unequable) measure of duration by the means of motion, which is commonly used instead of true time ... According to Newton, absolute time exists independently of any perceiver and progresses at a consistent pace throughout the universe. Unlike relative time, Newton believed absolute time was imperceptible and could only be understood mathematically. According to Newton, humans are only capable of perceiving relative time, which is a measurement of perceivable objects in motion (like the Moon or Sun). From these movements, we infer the passage of time. To quote Newton again: Absolute space, in its own nature, without regard to anything external, remains always similar and immovable. Relative space is some movable dimension or measure of the absolute spaces; which our senses determine by its position to bodies: and which is vulgarly taken for immovable space ... These notions imply that absolute space and time do not depend upon physical events, but are a backdrop or stage setting within which physical phenomena occur. Thus, every object has an absolute state of motion relative to absolute space, so that an object must be either in a state of absolute rest, or moving at some absolute speed.〔(Space and Time: Inertial Frames (Stanford Encyclopedia of Philosophy) )〕 To support his views, Newton provided some empirical examples: according to Newton, a solitary rotating sphere can be inferred to rotate about its axis relative to absolute space by observing the bulging of its equator, and a solitary pair of spheres tied by a rope can be inferred to be in absolute rotation about their center of gravity (barycenter) by observing the tension in the rope. Absolute time and space continue to be used in classical mechanics, but modern formulations by authors such as Walter Noll and Clifford Truesdell go beyond the linear algebra of elastic moduli to use topology and functional analysis for non-linear field theories.〔C. Truesdell (1977) ''A First Course in Rational Continuum Mechanics'', Academic Press ISBN 0-12-701301-6〕 ==Historical controversy== The idea of absolute space has proved particularly controversial from Newton's time to the present. For example, Leibniz was of the opinion that space made no sense except as the relative location of bodies, and time made no sense except as the relative movement of bodies. Bishop Berkeley suggested that, lacking any point of reference, a sphere in an otherwise empty universe could not be conceived to rotate, and a pair of spheres could be conceived to rotate relative to one another, but not to rotate about their center of gravity. A more recent form of these objections was made by Ernst Mach. Mach's principle proposes that mechanics is entirely about relative motion of bodies and, in particular, mass is an expression of such relative motion. So, for example, a single particle in a universe with no other bodies would have zero mass. According to Mach, Newton's examples simply illustrate relative rotation of spheres and the bulk of the universe.〔Ernst Mach; as quoted by 〕 When, accordingly, we say that a body preserves unchanged its direction and velocity ''in space'', our assertion is nothing more or less than an abbreviated reference to ''the entire universe''. These views opposing absolute space and time may be seen from a modern stance as an attempt to introduce operational definitions for space and time, a perspective made explicit in the special theory of relativity. Even within the context of Newtonian mechanics, the modern view is that absolute space is unnecessary. Instead, the notion of inertial frame of reference has taken precedence, that is, a preferred ''set'' of frames of reference that move uniformly with respect to one another. The laws of physics transform from one inertial frame to another according to Galilean relativity, leading to the following objections to absolute space, as outlined by Milutin Blagojević:
Newton himself recognized the role of inertial frames.〔Isaac Newton: ''Principia'', Corollary V, p. 88 in Andrew Motte translation. See the ''Principia'' on line at (Andrew Motte Translation )〕 The motions of bodies included in a given space are the same among themselves, whether that space is at rest or moves uniformly forward in a straight line. As a practical matter, inertial frames often are taken as frames moving uniformly with respect to the fixed stars. See Inertial frame of reference for more discussion on this. In 1903 Bertrand Russell wrote a defense of absolute space and time in ''Principles of Mathematics'', while admitting (page 465) that in the analysis of rational dynamics "non-Newtonian dynamics, like non-Euclidean geometry, must be as interesting to us as the orthodox system." 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「absolute time and space」の詳細全文を読む スポンサード リンク
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