– Ancient Babylonians were excellent astronomers who wrote down their observations on cuneiform tablets.
By studying ancient records of lunar and solar eclipses carved in clay tablets, dating back to 750 B.C., scientists can now confirm slowing of the Earth’s spin.
The speed of the planet’s spin has decelerated by 1.8 milliseconds per day per century. This might not sound like much, but in the distant future we will have a 25-hour day.
This was “significantly less”, than the rate of 2.3 milliseconds per century previously estimated—requiring a mere 2.6 million years to add one minute.
The science team point out that these estimates are approximate, because the geophysical forces operating on the Earth’s rotation will not necessarily be constant over such a long period of time. Intervening Ice Ages will disrupt these simple extrapolations.
Leslie Morrison, a retired astronomer with Royal Greenwich Observatory and his research team used gravitational theories about the movement of Earth around the Sun, and the Moon around Earth, to compute the timing of eclipses of the Moon and Sun over time, as viewed from our planet.
The next step was to calculate from where on Earth these would have been visible, and compare this to observations of eclipses recorded by ancient Babylonians, Chinese, Greeks, Arabs and medieval Europeans.
“We obtained historical, relevant records from historians and translators of ancient texts,” explained Morrison.
“For example, the Babylonian tablets, which are written in cuneiform script, are stored at the British Museum and have been decoded by experts there and elsewhere.”
The team found discrepancies between where the eclipses should have been observable, and where on Earth they were actually seen.