Scientists have come out with a startling fact that time span of each day has now become shorter than 24 hours. This they say is owing to the change in the speed of earth's rotation, which has increased over the last 5 decades.
Daily Mail reported that since 2020, every day is taking less than 24 hours. In fact, July 19, 2020 market the shortest day ever since data collection by scientists began in the 1960s.
The 28 fastest days on record (since 1960) all occurred in 2020, with Earth completing its revolutions around its axis milliseconds quicker than average. The year 2020 was already faster than usual, astronomically speaking.
What happened in 2020?
- According to Time and Date, Earth broke the previous record for shortest astronomical day, set in year 2005, 28 times.
- July 19, 2020 was 1.4602 milliseconds shorter than the regular 24 hours. This goes in direct opposition of previous records, under which the planet took longer than 24 hours to complete a rotation.
- In July 2020, the International Earth Rotation and Reference Systems Service (IERS) had announced that no 'leap second' would be added to the world's official timekeeping in December 2020.
What is Leap seconds?
- Leap seconds refer to adjustment of time, akin to leap years. According to the IERS, leap seconds have been added to 27 days since the 1970s.
- The most recent addition of leap second happened on December 31, 2016.
- Leap seconds are added on either the last day of June or December. This implies that the next potential date for a leap second is June 20, 2021.
A study from 2015 posited that this change in the earth's rotation may be due to global warming. Published in Science Advances, it claimed that the melting of glaciers is partly responsible for the planet to spin faster on its axis.
Scientists claim that on average, days are about 0.5 seconds shorter than 24 hours. Scientists around the world are considering whether to delete a second from time. Called a 'negative leap second', it would be done to account for the change, and to keep passage of time in sync with the Earth’s rotation.
Keeping atomic time in sync with solar time is important to keep satellites and other communications equipment in sync.
