Anybody Got the Time? You know what they say about time: it flies when you''re having fun. When you''re not, or when something''s as boring as watching paint dry, then time seems to stand still. Why is that? To understand, you have to wrap your brain around something that can''t be seen, bought, retrieved, or kept. Time, says the dictionary, is a duration of occurrence or a definitive instant when something happens; asking what time it is, and, therefore, needing to know your place in the continuum, is a little of both. Albert Einstein, in his Theory of Relativity, understood that the speed of light is absolute, can never be varied and is one of the most irreversible things in the universe. This means that time is a part of the universe, but to accommodate the precision of the speed of light, space and time must be flexible. It was Einstein''s teacher, Hermann Minkowski (1864-1909), who said that proper time was the distance between two events as measured by a clock that passes through both events, depending not only on the motion of the events but also on the motion of the clock itself. Coordinate time is the distance between the two events as measured by an observer.

To make it super simple, let''s say that the former is the amount of time it takes for a running back to make a touchdown; the latter is how much time you think it took. Though it''s a considerable subject to study, time, according to today''s physicists, doesn''t flow or move forward, backward, or, really, anywhere. Time just is , existing in a four-dimensional spacetime continuum that we just need to trust is there, and (to blow your mind a little) the past, present, and future all exist at once within the continuum with no defined direction of travel. As if that isn''t enough to absorb, there''s this: time can dilate, depending on the movement of the observers of any particular event. If there are two sport fans watching that running back and one of them is behind a camera onfield, his personal perception of time will be different from that of the couch potato. For everyday purposes, let''s assume that you want to know the time so you can set your DVR to record the game. There are websites you can find that will tell you exactly what time it is, but how do they know? To fully understand, it''s important to remember that, while humans had sundials and were aware of the sun rising and setting and had established the calendar year based on the sun, it was the Babylonians who divided the day into hours, minutes, and seconds based on a system they borrowed from the Sumerians. The Greeks and Chinese also devised systems of time, but since time was perceived by an individual''s observation, it differed (even if just a little bit) from person to person.

The truth is, in the beginning, having an exact time really didn''t matter much. Everyday folks and those who worked the land got up, worked until lunch (if there was one), and then went back to work until someone fixed the evening meal and, shortly thereafter, went to bed. Time was important but knowing the time was no big deal. You can''t exactly call them precise, but in the 15th century, clocks with springs began appearing in Europe, which proved better than relying on the skies for the time. More than two hundred years later, British carpenter and clockmaker John Harrison (1693-1776) invented the chronometer, which led to increased safety on the seas by allowing more accuracy when calculating longitude, which gave mariners a set place to calculate their positions when at sea. Not long after Harrison invented his instrument (and, by the way, collected a pile of prize money from the Board of Longitude), British clockmaker Thomas Mudge (1715-1794) invented the lever escapement, a piece of the clock''s guts that keeps internal parts moving. As the early 19th century rolled in, Eli Terry (1772-1852) had figured out how to mass-produce timepieces, making them more affordable for nearly anyone. By the turn of the 20th century, women were wearing watches on their wrists, but men used pocket watches almost exclusively until World War I, when soldiers found wristwatches to be much handier in battle.

Generally speaking, to determine the exact time, the world has agreed on the authority of two different timepieces created since the middle part of the last century: the atomic clock, which uses cesium-133 atoms and which has a ratio error of 1 second lost every 1.4 million years; and the cesium fountain atomic clock, which has a ratio error of 1 second lost every 20 million years (finessed later to an accuracy of 1 second lost every 100 million years). You can find the 100%-correct, inarguable, don''t-cross-me, win-a-bet, exact time, as per an atomic clock, online at www.time.gov. Fun Fact: Carolus Linnaeus (1707-1778), who was responsible for the binomial nomenclature classification system of living organisms, invented a floral clock to tell the time of day. He had observed over a number of years that certain plants consistently opened and closed their flowers at particular times of the day; these times varied from species to species. One could deduce the approximate time of day according to which species had opened or closed its flowers.

Linnaeus planted a garden displaying local flowers, arranging in sequence of flowering throughout the day. The clock would flower even on cloudy or cold days. He called it a "horologium florae" or "flower clock.".