Earth's Day Lengthens as Scientists Call It a Sign of the End Times on Earth
Jakarta — Recent research has revealed that Earth’s rotation is slowing, causing the length of a day on the planet to increase, albeit only in milliseconds.
A study conducted by geophysicists from Vienna and Zurich found that between 2000 and 2020, the length of a day on Earth increased by approximately 1.33 milliseconds per century. This represents the fastest rotational slowdown in millions of years, a period when giant mastodons and sabre-toothed cats were still alive.
The research utilised palaeoclimate data, particularly changes in global sea level since the Late Pliocene period approximately 3.6 million years ago.
One of the study’s authors, Benedikt Soja, professor of space geodesy at ETH Zurich, stated that this slowdown is closely related to modern climate change. “The rapid increase in the length of day demonstrates that the rate of modern climate change has not occurred for at least the Late Pliocene, approximately 3.6 million years ago,” he said. He added that this phenomenon is likely triggered by human activity.
Researchers describe the phenomenon as a redistribution of continental-oceanic masses. When polar ice sheets and mountain glaciers melt, the water flows into the ocean and adds mass to the water in low-latitude regions near the equator. This added mass creates additional resistance that slows Earth’s rotation.
Co-author Mostafa Kiani Shahvandi from the University of Vienna described the phenomenon using the analogy of an ice skater: “A skater will rotate more slowly when extending their arms and faster when their arms are close to their body.”
To calculate these changes, researchers used sea level fluctuation data obtained from fossils of microscopic marine organisms with shells called benthic foraminifera. From their chemical composition, scientists can trace changes in sea level and subsequently calculate their impact on the length of a day on Earth.
The research also employed a new artificial intelligence method called the Physics-Informed Diffusion Model (PIDM), which combines machine learning with the laws of physics to process highly complex palaeoclimate data.
Whilst the change in day length is measured only in milliseconds, its impact is considered important. Earth’s rotation is influenced by many factors, ranging from the movement of the planet’s core, atmospheric pressure, to the Moon’s orbit. However, in future, climate change is expected to become an increasingly dominant factor.
“By the end of the 21st century, climate change is estimated to influence the length of day even more strongly than the Moon’s influence,” Soja stated. He warned that although these changes are measured in milliseconds, they could create problems—for instance, in high-precision space navigation that requires extremely accurate information regarding Earth’s rotation.
The length of a day on Earth is known to vary considerably, although the changes are minimal. In some recent periods, Earth’s rotation has even accelerated. For example, on 4 July 2024, Earth recorded a record by completing one full rotation 1.66 milliseconds faster than usual.