The Earth has been mysteriously slowing down for 50 years - now scientists think they know why
Scientists are baffled by why the day seems to be getting longer
Your support helps us to tell the story
From reproductive rights to climate change to Big Tech, The Independent is on the ground when the story is developing. Whether it's investigating the financials of Elon Musk's pro-Trump PAC or producing our latest documentary, 'The A Word', which shines a light on the American women fighting for reproductive rights, we know how important it is to parse out the facts from the messaging.
At such a critical moment in US history, we need reporters on the ground. Your donation allows us to keep sending journalists to speak to both sides of the story.
The Independent is trusted by Americans across the entire political spectrum. And unlike many other quality news outlets, we choose not to lock Americans out of our reporting and analysis with paywalls. We believe quality journalism should be available to everyone, paid for by those who can afford it.
Your support makes all the difference.Planet Earth has begin spinning at a slower rate, making the days longer, and scientists are struggling to understand why.
In general, there are processes to point to that have lengthened the Earth’s day from its approximately 86,400-second length.
Over millions of years, the planet’s rotation has been slowing down due to friction caused by the Moon. Every 100 years, around 2.3 milliseconds is added to the length of a day – billions of years ago, a day on Earth only lasted 19 hours.
Now, however, the Earth’s continual slowness is unprecedented and has gone on for the past 50 years and, overall, Earth’s spin has slowed by about 6 hours in the past 2740 years, according to a study published in the Proceedings of the Royal Society A in 2016.
“It is found that the rate of rotation departs from uniformity, such that the change in the length of the mean solar day (lod) increases at an average rate of +1.8 ms per century. This is significantly less than the rate predicted on the basis of tidal friction, which is +2.3 ms per century”, the researchers wrote.
The Earth reached its shortest day on 29 June 2022, but the general trend is that the days are lengthening – with no explanation readily available.
There are a few theories: weather systems melting the ice sheets could have an effect over the long-term, as at lower altitudes the planet is shrinking inwards. However, these have been decreasing at a consistent rate, so may not fit such a sudden change.
It is possible that fluctuations in the planet’s rotational speed known as the "Chandler wobble" – where small, irregular movement of Earth’s geographical poles across the surface of the globe – could be causing an impact.
Finally, processes in Earth’s inner or outer layers, oceans, tides, or even climate, may be causing it. Major earthquakes can also change the length of a day, but the amount is usually miniscule.
Join our commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies
Comments