Home > Intellectual history of time
When one speaks about the intellectual history of time, one essentially is stating that changes have occurred in the way we experience and measure time. Our conceived abstract notions of time have presumably developed in accordance with our art, our science, and our social infrastructure. (See also horology.)1 Towards time-keeping
The units of time first developed by humans would likely have been days and months (moons). In some parts of the world the cycle of seasons are apparent enough to lead to people speaking about years & seasons (e.g. 4 summers ago, or 4 floods ago). With the invention of agriculture in the 3rd millennium BC, people relied heavily on the cycles of the season for planting and harvesting crops. Most humans came to live in settled societies and the whole community relied upon accurate predictions of the seasonal cycle. This led to the development of calendars. Over time, some people came to recognize patterns of the stars with the seasons. Learning astronomy became an assigned duty for certain people so they could coordinate the lunar and solar calendars by adding days or months to the year.
At about the same time, sundials were developed, likely marked first at noon. Adding marks for sunrise and sunset would lead to those further away from the equator noticing that there was a wide variation with a pattern. More marks were added and eventually numbers so that people began to talk about hours. Ancient traditions did not begin the day at midnight, but rather some at dawn, others at dusk. Many cultures also fixed both day and night at 12 hours (which leads to hours being a different length in different seasons the further you are from the equator). {How 12 came to mark noon, 6 dawn (in the tropics, anyway), and how 1 came to be in the afternoon likely relates to the much later development of dials on mechanical clocks.} In those days, anyway, the idea of "10:14 A.M." or "6:23 P.M." would be meaningless - a sundial isn't that precise, having only one "hand". It took centuries for technology to make measurements precise enough for minutes (and later seconds) to become fixed meaningful units -- longer still for milliseconds, microsecondA microsecond is an SI unit of time equal to one millionth (10-6) of a second. It is often used for measuring things like atomic and chemical reactions, which occur in normally imperceptible lengths of time. Its symbol is s . See also 1 E-6 s for compariss, nanoseconds, picoseconds, femtoseconds, or attoseconds.
When the water clockA water clock or clepsydra is a device for measuring time by letting water regularly flow out of a container usually by a tiny aperture. History Water clocks were among the earliest timekeepers that did not depend on the observation of celestial bodies. was invented, time could also be measured at night - though there was significant variation in flow rate and so not great accuracy nor precisionIn Wikipedia, precision has the following meanings: #In engineering, science, industry and statistics, precision characterises the degree of mutual agreement among a series of individual measurements, values, or results see accuracy and precision. In comp. With the invention of the hourglassAn hourglass also known as a "sandglass" is a device for the measurement of time. It consists of two glass bulbs placed one above the other which are connected by a narrow tube. One of the bulbs is usually filled with fine sand which flows through the nar (perhaps as early as the 11th Century) hours and units of time smaller than a hour could be measured quite reliably.
The earliest reasonably accurate mechanical clockA clock (from the Latin cloca " bell") is an instrument for measuring time. A clock can be a physical instrument (an especially accurate one is called a chronometer). The clock in its modern form (24 hour clock) has been in use since at least the 15th cens are the 13th century tower clocks probably developed for (and perhaps by) monks in Northern Italy. These were adjusted to conform with canonical hoursCanonical hours are ancient divisions of time (also called "offices"), developed by the Christian Church, serving as increments between prayers. The practice grew from the Jewish practice of reciting prayers at set times of the day: for example, in the bo -- which varied with the length of the day.
