December 31 2016 Leap Second

On New Year's Eve an extra second will be added to the end of the day. This extra second is called a leap second. As I'll explain later, leap seconds need to be added periodically to bring the time we measure with accurate atomic clocks in line with the natural time which results from the rotation of the… Continue reading December 31 2016 Leap Second

Jun 30 2015 – Leap Second

On June 30 2015 an extra second will be inserted into the very end of the day. This extra second is called a leap second.   Why do we need leap seconds? Although we take the average length of a day to be 24 hours, the mean solar day, or average "natural" day measured by the… Continue reading Jun 30 2015 – Leap Second

The Days are Getting Longer.

  Although the Moon  is less massive than the Earth its gravitational field still has significant effects on the Earth. The most noticeable of these are tides, the periodic rise and fall of sea levels. The principle cause of tides is that the pull of the Moon’s gravity is stronger at the area of the Earth… Continue reading The Days are Getting Longer.