http://www.w3.org/TR/owl-time/
There are two distinct views on the meaning of the word time.
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One view is that time is part of the fundamental structure of the universe, a dimension in which events occur in sequence, and time itself is something that can be measured. This is the realist's view, to which Sir Isaac Newton subscribed, and hence is sometimes referred to as Newtonian time.[1]
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A contrasting view is that time is part of the fundamental human intellectual structure (together with space and number) within which we sequence events, quantify the duration of events and the intervals between them, and compare the motions of objects. In this second view, time does not refer to any kind of entity that "flows", that objects "move through", or that is a "container" for events. This view is in the tradition of Gottfried Leibniz[2] and Immanuel Kant,[3][4] in which time, rather than being an objective thing to be measured, is part of the measuring system used by humans.
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In physics, time and space are considered fundamental quantities (i.e. they cannot be defined in terms of other quantities because other quantities – such as velocity, force, energy, etc – are already defined in terms of them). Thus the only definition possible is an operational one, in which time is defined by the process of measurement and by the units chosen.
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Periodic events and periodic motion have long served as standards for units of time. Examples are the apparent motion of the sun across the sky, the phases of the moon, the swing of a pendulum, heartbeats, etc. Currently, the unit of time interval (the second) is defined as a certain number of hyperfine transitions in Cesium atoms (see below).
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Time has long been a major subject of science, philosophy, and art. Its measurement has occupied scientists and technologists, and was a prime motivation in astronomy. Time is also of significant social importance, having economic value ("time is money") as well as personal value, due to an awareness of the limited time in each day and in human lifespans.<br><br>
<a href="http://en.wikipedia.org/wiki/Time">Wikipedia entry</a>
A finite state machine (FSM) or finite state automaton (plural: automata) or simply a state machine is a model of behavior composed of a finite number of states, transitions between those states, and actions.
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<a href="http://en.wikipedia.org/wiki/State_machine">Wikipedia entry</a>
In classical mechanics, momentum (pl. momenta; SI unit kg m/s, or, equivalently, N·s) is the product of the mass and velocity of an object. For more accurate measures of momentum, see the section "modern definitions of momentum" on this page. It is sometimes referred to as linear momentum to distinguish it from the related subject of angular momentum. Linear momentum is a vector quantity, as it takes into account the direction of the value.
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Momentum is a conserved quantity, meaning that the total momentum of any closed system (one not affected by external forces) cannot change.
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The concept of momentum in classical mechanics was originated by a number of great thinkers and experimentalists. The first of these was Ibn Sina (Avicenna) circa 1000, who referred to impetus as proportional to weight times velocity.[1] René Descartes later referred to mass times velocity as the fundamental force of motion. Galileo in his Two New Sciences used the term "impeto" (Italian), while Newton's Laws of Motion uses motus (Latin), which has been interpreted by subsequent scholars to mean momentum.[citation needed]
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<a href="http://en.wikipedia.org/wiki/Momentum">Wikipedia entry</a>
This document presents an ontology of temporal concepts, OWL-Time (formerly DAML-Time) [4,10], for describing the temporal content of Web pages and the temporal properties of Web services. The ontology provides a vocabulary for expressing facts about topological relations among instants and intervals, together with information about durations, and about datetime information. We also demonstrate in detail, using the Congo.com and Bravo Air examples from OWL-S [11], how this time ontology can be used to support OWL-S, including use cases for defining input parameters and (conditional) output parameters. A use case for meeting scheduling is also shown. In the appendix we also describe a time zone resource in OWL we developed for not only the US but also the entire world, including the time zone ontology, the US time zone instances, and the world time zone instances.
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<a href="http://www.w3.org/TR/owl-time/">W3C entry</a>
The idea of space has been of interest for philosophers and scientists for
much of human history. The term is used somewhat differently in different
fields of study, hence it is difficult to provide an uncontroversial and
clear definition outside of specific defined contexts. Disagreement also
exists on whether space itself can be measured or is part of the measuring
system. (See Space in philosophy.) Science considers space to be a
fundamental quantity (a quantity which can not be defined via other
quantities because other quantities — like force and energy — are already
defined via space). Thus an operational definition is used in which the
procedure of measurement of space intervals (distances) and the units of
measurement are defined.
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<a href="http://en.wikipedia.org/wiki/Space">Wikipedia entry<a>
A physical law, scientific law, or a law of nature is a scientific generalization based on empirical observations of physical behavior. Empirical laws are typically conclusions based on repeated scientific experiments over many years, and which have become accepted universally within the scientific community. The production of a summary description of nature in the form of such laws is a fundamental aim of science.
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Laws of nature are distinct from religious and civil law, and should not be confused with the concept of natural law. Nor should 'physical law' be confused with 'law of physics' - the term 'physical law' usually covers laws in other sciences (e.g. biology) as well.
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Mass is a fundamental concept in physics, roughly corresponding to the intuitive idea of "how much matter there is in an object". Mass is a central concept of classical mechanics and related subjects, and there are several definitions of mass within the framework of relativistic kinematics (see mass in special relativity and mass in General Relativity). In the theory of relativity, the quantity invariant mass, which in concept is close to the classical idea of mass, does not vary between single observers in different reference frames.
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In everyday usage, mass is more commonly referred to as weight, but in physics and engineering, weight means the size of the gravitational pull on the object; that is, how heavy it is, measured in units of force. In everyday situations, the mass and weight of an object are directly proportional to each other, which usually makes it unproblematic to use the same word for both concepts. However, the distinction between mass and weight becomes important:
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* for measurements with a precision better than a few percent, due to slight differences in the strength of the Earth's gravitational field at different places
* for places far from the surface of the Earth, such as in space or on other planets
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<a href="http://en.wikipedia.org/wiki/Mass">Wikipedia entry</a>
A physical constant is a physical quantity that is generally believed to be both universal in nature and constant in time. It can be contrasted with a mathematical constant, which is a fixed numerical value but does not directly involve any physical measurement.
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There are many physical constants in science, some of the most widely recognized being the rationalized Planck's constant h, the gravitational constant G, the speed of light in the vacuum c, the electric constant ε0, and the elementary charge e. Physical constants can take many dimensional forms: the speed of light signifies a maximum speed limit of the universe and is expressed dimensionally as length divided by time; while the fine-structure constant α, which characterizes the strength of the electromagnetic interaction, is dimensionless.
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<a href="http://en.wikipedia.org/wiki/Physical_constant">Wikipedia entry</a>
In physics and other sciences, energy (from the Greek ενεργός, energos, "active, working")[1] is a scalar physical quantity that is a property of objects and systems which is conserved by nature. Several different forms, such as kinetic, potential, thermal, electromagnetic, chemical, nuclear, and mass have been defined to explain all known natural phenomena.
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Energy is converted from one form to another, but it is never created or destroyed. This principle, the conservation of energy, was first postulated in the early 19th century, and applies to any isolated system. According to Noether's theorem, the conservation of energy is a consequence of the fact that the laws of physics do not change over time.[2]
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Although the total energy of a system does not change with time, its value may depend on the frame of reference. For example, a passenger in a moving airplane has zero kinetic energy relative to the airplane, but nonzero kinetic energy relative to the earth.
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<a href="http://en.wikipedia.org/wiki/Energy">Wikipedia entry</a>
There are 5 states of matter: Gas, Liquid, Solid, Plasma, and Boise Einstien Condensate.
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In science matter is commonly defined as the substance of which physical objects are composed, not counting the contribution of various energy or force-fields, which are not usually considered to be matter per se (though they may contribute to the mass of objects). Matter constitutes much of the observable universe, although again, light is not ordinarily considered matter. Unfortunately, for scientific purposes, "matter" is somewhat loosely defined.
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<a href="http://en.wikipedia.org/wiki/Matter">Wikipedia entry</a>
In physics, a fundamental interaction or fundamental force is a mechanism by which particles interact with each other, and which cannot be explained in terms of another interaction. Every observed physical phenomenon can be explained by these interactions. The apparent irreducible nature of these interactions leads physicists to study the properties of these forces in great detail. In modern physics, there are four fundamental interactions (forces): gravitation, electromagnetism, the weak interaction, and the strong interaction. Their magnitude and behavior vary greatly, as described in the table below.
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<a href=http://en.wikipedia.org/wiki/Fundamental_interaction">Wikipedia entry</a>
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The Universe is everything that exists: the entirety of space and time,
all forms of matter, energy and momentum, and the physical laws and
physical constants that govern them. In a well-defined, mathematical
sense, the universe can even be said to contain that which does not
exist; according to the path-integral formulation of quantum mechanics,
even unrealized possibilities contribute to the probability amplitudes
of events in the universe.[1] The universe is sometimes denoted as the
cosmos or Nature, as in "cosmology" or "natural philosophy".
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<a href="http://en.wikipedia.org/wiki/Universe">Wikipedia entry</a>
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