Shorter Days, Faster Rotations — What’s Up With Earth?

Imagine you’re in an exam hall. It’s been a challenging paper, but you have cracked every question just in the nick of time, except for the last one. “Three mins to go!” the examiner says. “Tie your sheets and write!” 

But you are too engrossed in answering the last question to even listen to the examiner. It’s a five-mark question of the final section, and you are frantically trying to finish answering it. 

Before you know it, the school bell rings, indicating the end of the exam, and the examiner starts collecting the answer sheets! As she approaches your row you realise you’re yet to tie your sheets. So, in a matter of seconds, you quickly string them all together and submit the paper before the examiner can reprimand you. Exam saved!

Image Source: Giphy

We’ve all been there, haven’t we? In exam halls, matches and quizzes, even a tiny unit of time, like the second, becomes all-powerful. In a matter of just a few seconds things can change in these high-pressure situations, just like tying your answer sheet just in time can save the exam!

However, in the year 2020, the concept of the second gained quite a bit of attention, that too outside high-pressure situations like an exam.  Last year, scientists carefully examined the number of seconds it took for the Earth to complete one rotation on its axis. They studied this with perhaps the same frantic concentration that a student would while watching time run out during an important exam.

Why, though? 

Because after decades of slowing down, the Earth is spinning faster!

What’s up with the Earth?

Based on timekeeping records, the Earth was spinning faster in the year 2020. Usually, it takes the Earth 86,400 seconds to complete one rotation.  However, this is not an exact number and for many years, the Earth in fact has been slowing down. To make up for this time lag, scientists used to add a ‘leap second’ to their clocks to ensure our time is in sync with the Earth’s rotation.

Read Also: Why is February so odd this year?

But, after 50 years of slowing down, the Earth is now spinning faster.

How fast was the Earth in 2020?

The year 2020 had 28 days super short days. In fact these 28 days were the shortest ever recorded in human history. This means that since humans started recording time, the Earth has never spun this fast! Overall, a day on Earth now is half a millisecond shorter than 24 hours.

Image Source: Giphy

Some scientists estimate that by the time the current year is done, 2021 might be 34 milliseconds shorter than previous years.

Why is the Earth spinning faster? 

There are a lot of things that affect the rotation of the Earth. The molten core inside the planet, the atmosphere and even the Moon — these are some of the things that play a role determining the rate of Earth’s spin. However, one theory suggests that the melting of polar ice caps due to global warming has made our planet rounder thereby making it spin faster.

Image Source: Giphy

This timelapse shows how many polar ice caps melted in just the year 2016. 

What are the effects of shorter planetary rotation?

Firstly, satellites cannot be adjusted to the shorter rotation of the Earth. This could make GPS systems slightly inaccurate by just a few seconds. A faster rate of spin could also alter our ability to predict celestial events like eclipses. 

A few milliseconds shredded off our daily schedule may not seem like a lot now, but its accumulated effect could be astounding! If your day got shorter, what are some of the things you would rush to do?

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