Thursday, January 19, 2012

Strategic Time, or, Can't stop won't stop

The ITU Radiocommunication Assembly has reached an important decision to defer the development of a continuous time standard in order to address the concerns of countries that use the current system of the leap second in Coordinated Universal Time...



Adjustments made in one second steps, known as ‘leap seconds’, have been implemented since 1972 to compensate for variations in the speed of the earth’s rotation...

The suppression of the leap second would make continuous time scale available for all the modern electronic navigation and computerized systems to operate with and eliminate the need for specialized ad hoc time systems. This however may have social and legal consequences when the accumulated difference between UT1 – Earth rotation time – would reach a perceivable level (2 to 3 minutes in 2100 and about 30 minutes in 2700).
Source.

Emphasis mine.



The Earth's rotation speed can be measured using different techniques...

The rotation data shows oscillations over several different timescales. The one with the largest variation is seasonal: Earth slows down in January and February.

"It turns out that during the Northern Hemisphere winter, the winds - which are predominantly west to east - are stronger," Salstein said.

The more forceful winds double the angular momentum of the atmosphere...

This means the days get longer - by a few thousandths of a second.

Source.

1 comment:

  1. One day is 23 hours 56 minutes. You'd think I'd be less tired with that extra sleep time...

    ReplyDelete