The days really do get shorter as you get older, although even the Old Testament patriarch Methuselah, who is supposed to have lived 969 years, is unlikely to have been troubled by the phenomenon.
That is because the rate at which this is happening is very, very slow: only two-and-half milliseconds a century, according to Dr Ludwig Combrinck of the Hartebeesthoek Radio Astronomy Observatory, located west of Johannesburg.
Combrinck was responding to questions from Sapa about an investigation his observatory is participating in — along with seven other facilities around the world — to more accurately measure aspects of the Earth’s rotation rate.
This is being done using quasars — described by Combrinck as ”galaxies with a black hole in the middle” — as a point source, or reference point.
About 200 quasars, which emit radio waves, are located on the edge of the known universe, and have been the subject of intensive astronomical study since about 1960, are being used for the investigation.
The international investigation started on Wednesday this week and ends on October 31. Hartebeesthoek is South Africa’s national research facility for radio astronomy and space geodesy, and is managed by the National Research Foundation (NRF).
”The 26-metre radio telescope at Hartebeesthoek is forming part of a global network of eight radio telescopes studying the earth,” Combrinck said.
The other seven sites were located in Europe, the United States and Hawaii. ”The eight large radio antennas are making continuous measurements for 24 hours every day as part of an intensive campaign called CONT02.”
The Hartebeesthoek telescope was the only one in the network located in the southern hemisphere. ”The long north-south baselines from the northern telescopes to Hartebeesthoek are of particular importance in improving the accuracy of the results.
”The radio antennas will use the measuring technique of very long baseline interferometry, which receives the natural radio waves from quasars near the edge of the visible universe,” Combrinck said.
He said the study would provide many benefits. ”The study of the earth, its atmosphere and oceans, the solid ground beneath us down to the fluid iron outer core and solid iron inner core, is important for many reasons. ”These range from understanding the world we live in, to practical applications such as better weather forecasting, better navigation of airliners, our private cars, or interplanetary spacecraft.”
One interesting fact to emerge is that the planet we live on is losing two-and-a-half milliseconds evey hundred years.
”That is the rate of slowing down in the Earth’s rotation,” Combrinck said. – Sapa