Earth not slowing down anymore.
Posted: Fri Jan 02, 2004 5:29 pm
Thought this was interesting.....
.Punctual Earth Baffles Expert Clock-Setters
Planet Not Lagging Since Before 1999
POSTED: 6:49 p.m. EST January 1, 2004
BOULDER, Colo. -- The Earth is spinning right on schedule for a fifth straight year, and that has scientists scratching their heads.
Experts generally agree the rate at which the Earth spins on its axis has slowed ever so slightly for millennia. To make the world's official time agree with where the Earth actually is, scientists in 1972 started adding a "leap second." For 28 years, scientists repeated the procedure, but in 1999, they discovered the Earth was no longer lagging behind.
At the National Institute of Standards and Technology in Boulder, spokesman Fred McGehan said scientists aren't sure why the Earth is suddenly on schedule. Possible explanations include the tides, weather and changes in the Earth's core, he said.
The leap second was an unexpected consequence of the 1955 invention of the atomic clock, which use the electromagnetic radiation emanated by Cesium atoms to measure time. It is extremely reliable.
Atomic-based Coordinated Universal Time was implemented in 1972, superseding the astronomically determined Greenwich Mean Time.
Leap seconds can be a big deal, affecting everything from communication, navigation and air traffic control systems to the computers that link global financial markets
