There are two distinct views on the meaning of time. One view is that time is part of the fundamental structure of the universe, a dimension in which events occur in sequence. This is the realist view, to which Sir Isaac Newton [1] subscribed, in which time itself is something that can be measured.
A contrasting view is that time is part of the fundamental 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 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 mental measuring system.
Many fields avoid the problem of defining time itself by using operational definitions that specify the units of measurement that quantify time. Regularly recurring events and objects with apparent 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, and the swing of a pendulum.
Time has long been a major subject of science, philosophy and art. The measurement of time has also occupied scientists and technologists, and was a prime motivation in astronomy. Time is also a matter 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. This article looks at some of the main philosophical and scientific issues relating to time.
Many ancient philosophers wrote lengthy essays on time, believing it to be the essence around which life was based. A famous analogy was one that compares the time of life to the passing of sand through an hourglass. The sand at the top is the future, and, one tiny grain at a time, the future flows through the present into the past. The past ever expanding, the future ever decreasing, but the future grains being moulded into the past through the present. This was widely discussed in around the 3rd century CE. [citation needed]
The earliest recorded philosophy of time was expounded by Ptahhotep, who lived c.2650 -2600 BC said: "Do not lessen the time of following desire, for the wasting of time is an abomination to the spirit."
In the Old Testament book Ecclesiastes, traditionally thought to have been written by King Solomon (970-928 BC), time was regarded as a medium for the passage of predestined events.
"There is an appointed time for everything. And there is a time for every event under heaven— A time to give birth, and a time to die; A time to plant, and a time to uproot what is planted. A time to kill, and a time to heal; A time to tear down, and a time to build up. A time to weep, and a time to laugh; A time to mourn, and a time to dance. A time to throw stones, and a time to gather stones; A time to embrace, and a time to shun embracing. A time to search, and a time to give up as lost; A time to keep, and a time to throw away. A time to tear apart, and a time to sew together; A time to be silent, and a time to speak. A time to love, and a time to hate; A time for war, and a time for peace." (Ecclesiastes 3:1–8)
Around 500 BC Heraclitus, a fatalist, held that the passage of time and the future both lay beyond the possibility of human influence: "Everything flows and nothing abides; everything gives way and nothing stays fixed. You cannot step twice into the same river, for other waters and yet others, go flowing on. Time is a child, moving counters in a game; the royal power is a child's."
[edit] Time in philosophy
Newton believed time and space form a container for events, which is as real as the objects it contains.
"Absolute, true, and mathematical time, in and of itself and of its own nature, without reference to anything external, flows uniformly and by another name is called duration. Relative, apparent, and common time is any sensible and external measure (precise or imprecise) of duration by means of motion; such a measure - for example, an hour, a day, a month, a year - is commonly used instead of true time." -Principia [16]
In contrast to Newton's belief in absolute space, and closely related to Kantian time, Leibniz believed that time and space are a conceptual apparatus describing the interrelations between events. The differences between Leibniz's and Newton's interpretations came to a head in the famous Leibniz-Clark Correspondence. Leibniz thought of time as a fundamental part of an abstract conceptual framework, together with space and number, within which we sequence events, quantify their duration, and compare the motions of objects. In this view, time does not refer to any kind of entity that "flows," that objects "move through," or that is a "container" for events.
Immanuel Kant, in the Critique of Pure Reason, described time as an a priori intuition that allows us (together with the other a priori intuition, space) to comprehend sense experience. With Kant, neither space nor time are conceived as substances, but rather both are elements of a systematic mental framework necessarily structuring the experiences of any rational agent, or observing subject. Spatial measurements are used to quantify how far apart objects are, and temporal measurements are used to quantify how far apart events occur. Similarly, Schopenhauer stated in the preface to his On the Will in Nature that "Time is the condition of the possibility of succession."
In Existentialism, time is considered fundamental to the question of being, in particular by the philosopher Martin Heidegger. See Ontology.
[edit] Time as "unreal"
In 5th century BC Greece, Antiphon the Sophist, in a fragment preserved from his chief work Truth held that: "Time is not a reality (hupostasis), but a concept (noêma) or a measure (metron)." Similarly, Parmenides believed that time, motion, and change were illusions, leading to Zeno's paradoxes (Zeno was a follower of Parmenides).
Ralph Waldo Emerson considers time as presentness, where past and future are but our present projections (of our memory, hope, etc.). For Emerson, time needs a qualitative measurement rather than a quantitative one.[citation needed]
Writers such as J. M. E. McTaggart in his 1908 The Unreality of Time have argued that time is an illusion (see also The flow of time).
Psychology
Different people may judge identical lengths of time quite differently. Time can "fly"; that is, a long period of time can seem to go by very quickly. Likewise, time can seem to "drag," as in when one performs a boring task. The psychologist Jean Piaget called this form of time perception "lived time."
Time also appears to pass more quickly as one gets older. For example, a year for a five-year-old child is 20% of his entire life so far, however for a 50 year old adult a year is only 2% of his entire life so far; so with increasing age, each segment of time is a decreasing percentage of the person's total experience.
Altered states of consciousness are sometimes characterised by a different estimation of time. Some psychoactive substances--such as entheogens--may also dramatically alter a person's temporal judgement. When viewed under the influence of such substances as LSD, magic mushrooms and peyote, a clock may appear to be a strange reference point and a useless tool for measuring the passage of events as it does not correlate with the user's experience. At higher doses, time may appear to slow down, stop, speed up and even go backward when under the influence of these agents. A typical thought might be "I can't believe it's only 8 o'clock, but then again, what does 8 o'clock mean?" As the boundaries for experiencing time are removed, so is its relevance. Many users claim this unbounded timelessness feels like a glimpse into spiritual infinity. To imagine that one exists somewhere "outside" of time is one of the hallmark experiences of a psychedelic voyage. Marijuana may also distort the perception of time, although, to a lesser degree than psychedelics.
The practice of meditation, central to all Buddhist traditions, takes as its goal the reflection of the mind back upon itself, thus altering the subjective experience of time; the so called, 'entering the now', or 'the moment'.
In explaining his theory of relativity, Albert Einstein is often quoted as saying that although sitting next to a pretty girl for an hour feels like a minute, placing one's hand on a hot stove for a minute feels like an hour. This is intended to introduce the listener to the concept of the interval between two events being perceived differently by different observers.
2007-01-02 04:10:42
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answer #7
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answered by Deathliger 2
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