Days on Earth will be 25 hours long as the planet's rotation slows down

British scientists calculate that in the future, a day on Earth will be 25 hours long because the planet's rotation speed is getting slower.

The Earth rotates nearly two milliseconds slower every century. Photo: YouTube.

Ancient records from Babylonian, Chinese, Greek and Arab civilizations indicate that Earth’s rotation is slowing down. By examining records of eclipses (including solar and lunar eclipses) dating back to 720 BC, scientists have concluded that Earth’s days are getting longer by nearly two milliseconds (0.002 seconds) every 100 years, International Business Times reported.

Scientists have long noticed that the Earth is slowing down. When the planet first formed, a day was only 6 hours long. About 200 million years ago, during the time of the dinosaurs, a day was 23 hours long. In another 200 million years, scientists estimate that a day will be 25 hours long.

To understand exactly how the Earth's rotation has changed over the past few thousand years, a team from Durham University and the UK's HM Nautical Almanac Office looked at ancient records dating back 2,700 years.

Starting with Babylonian records, the team looked at how the ancient civilization measured the start and end times and pinpointed the locations. They used documents from China, Greece, medieval Europe and Arabia to create "the most comprehensive list of observations to date to study variations in Earth's rotation since 720 BC."

Scientists compared the records with computer models that showed when and where eclipses would have occurred thousands of years ago if Earth's rotation had not changed. The findings, published yesterday in the journal Proceedings of the Royal Society A, showed that Earth's rotation is slowing by about 1.8 milliseconds per century.

This slowing is partly due to tidal forces. The Earth rotates faster than the Moon. The Moon's gravity acts on the tides, slowing down the Earth's rotation. "Assuming that the measurement of tidal braking in the Earth-Moon-Sun system is correct, we conclude that this mechanism alone is not sufficient to explain the observed slowing in rotation over the past 2,700 years," the team said.

According to VNE