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Another matter of interest is the year.  In addition to turning on its own axis, the earth also moves in the huge path around the sun.  The time required to make the trip from any point in this path back to the starting point determines the year.  That interval is 365¼ days, and not an even 365 as is so generally believed.
            This brings us to another division of time—the month.  A month is fixed by the number of days it takes the moon to make a complete trip around the earth.  That interval is 29½ days.  Obviously, 365¼ divided by 29½ does not result in an even number of months.  Provision for the unevenness was made in the year 1582, when our present calendar was established with twelve months of varying length, plus an extra day every four years to absorb the accumulated quarter days required by the earth in its trip around the sun.  
            Time is used for so many varied and exacting purposes that reliable facilities must be provided to supply accurate time measurements.  That need is met by the United States Naval Observatory in Washington.  Every two hours, the Observatory sends out a radio signal that is accurate within 1/8000th of a second.
            Many of our everyday comforts and conveniences rely on efficient operation of time.  The electric clock, for example, is dependable only because the power company can supply current with an unvarying number of oscillations within an exact period of one second.  The radio can be tuned to different programs only because each station broadcasts on an exact frequency of kilocycles per second.  Lighthouses are identified by mariners by the fixed frequency of their signals.
            But whatever the use may be, the master clock that controls the accuracy of every man-made timing device is the constant and unvarying rotation of old Mother Earth herself.


Last modified: Sunday, 6 June 2021, 6:41 PM