Tuesday 18 October 2016

Understanding leap second adjustment



December 31st 2016 will be one second longer as a leap second is added to atomic clocks everywhere in the world. Atomic clocks are derived from a variant of the cesium atom. The metallic element cesium ticks unfailingly at nine billion times a second. The scale of slicing time to that atomic level is incomprehensible. The atomic clock is the UTC (coordinated universal time) which is set by the International Bureau of Weights and Measures located in Paris. The time is set after getting information from about 50 countries and the average computed by consensus.



The need to add a leap second
Time is based on the rotation of the Earth. This rotational time is divided into 86,400 seconds (24 hours x 60 minutes x 60 seconds = one day). The Earth spins slower each year due to pull of tides and other internal factors, which create the difference between the atomic time and exact or rotational time.



So is one second important?
Yes, in satellite systems one-second difference is too much as navigation systems operate on the measurement of time it takes for a signal to traverse from a receiver and a satellite. Light travels 30 centimetres in one billionth of a second. Cellular networks will be out of sync if this time is not adjusted. So is the case with electricity grids. Ships at sea will get lost 



Fortunately our personal timekeeping watches do not have to undergo this exactness unlike the Shepherd 24-hour atomic clock on the gate of Greenwich's Royal Observatory in England. The difference between rotational time and atomic clock is one hour for 1000 years. Just a normal adjustment is required for regular watches. But what is important is regular servicing by watchmakers.. If you happen to own a Patek Philippe or A Lange Sohne watch then checking the Perpetual Time reviews should give you an idea of who and where to approach for reputed servicing.

Perpetual Time reviews on watch forums is the place to refer for knowledgeable advice on watch restoration and service of rare watches.

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