Leap Second Row

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Leap second row reported in BBC News, 27 Sep 2005 and 9 Nov 2005. Fifty years ago scientists began measuring time using the resonance frequencies of atoms. These atomic clocks are very precise and now are used as the standard for Coordinated Universal Time (UTC). Atomic time is used by telecommunications, computing and global positional satellites. Prior to atomic time being the standard, solar time, based on the rotation of the earth was the standard. Solar time is essential for locating satellites and for anyone studying natural phenomena related to the rising and setting of the sun, eg. for astronomers to precisely position their telescopes. There is a very tiny difference between solar and atomic time because the earth's rotation is slowing down due to tidal friction. To compensate for this difference, leap seconds have to be added to UTC occasionally. The first time this happened was in 1972 and it has happened 21 times since then, the most recent being 1998. Another leap second is planned for 31 December 2005, but a group of Americans at the International Telecommunication Union meeting in Geneva wanted to abolish leap seconds and not adjust UTC until the difference between atomic and solar time reaches an hour. However, the leap second will go ahead and a working party has been established to consider the options. The Royal Astronomical Society pointed out that the idea of clock time following solar time was deeply embedded in our culture, and Daniel Gambis of the Earth Rotation Service in Paris commented: "I don't support the American delegation because I think all human activities are linked to the rotation of the earth first."

Editorial Comment: In the beginning, reports Genesis, God established the sun, moon and stars to serve mankind for signs, times and seasons (Genesis 1:14). This means we are meant to keep times and dates by astronomical observations. Atomic time may be very accurate over short times but it may have varied by large amounts over the history of the earth. One of the factors that determine atomic movements is the speed of light. There is good evidence that the speed of light has changed since the beginning of the world. This is one of the reasons radioactive dates give such large numbers. It is good atomic time, but it does not relate to how many times the earth has revolved around the sun. (Ref. calendar, clock, astronomy)

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