Networks

The International Earth Rotation and Reference Systems Service (IERS) announced upcoming insertion of a Leap Second on June 30, 2012. This is the 24th leap second added, and the first since Dec 31, 2008. After UTC is retarded in June, GPS time will be ahead of UTC by 16 seconds rather than 15 seconds. Leap seconds were adopted in 1972 because modern clocks mark time more accurately than the rotation of the Earth. The Earth as a clock has lost about 3 hours over the past 2000 years.

Also the ITU may vote this week on a proposal, effective in 2018, to eliminate leap seconds, which will result in a drift between the mean solar day and UTC of about 140 sec by the end of the century. This proposed change, led by USA and France, will mitigate industry problems in synchronizing communications and financial networks, however the resulting drift will accelerate as the Earth slows, leaving future generations to decide whether it is desirable to keep civil time in sync with the sun, and how best to accomplish this.