Since the Earth breaks the atomic clock invention, the record of the shortest rotation one day

Elephant reporter Wu Bin/Compilation

According to a report on August 8th, Eastern time in CNN, on June 29th, the earth rolling one day was 1.59 milliseconds shorter than 24 hours, breaking the short -term record since the invention of the atomic clock.

If you feel that one day is getting less, you feel right.

Scientists have recorded the shortest day on the earth since the invention of the atomic clock. The atomic clock is a standardized measurement unit that has been used for time and measure the earth's rotation since the 1950s.

According to data from the international earth rotation and reference system service organizations responsible for global timing, on June 29, the time of the earth rotation was 1.59 milliseconds shorter than the normal 24 hours. Rotary is the time required for the earth to rotate around its axis, about 86400 seconds. The shortest time record of the previous earth rotation was July 19, 2020, which was 1.47 milliseconds shorter than the normal rotation time.

Although the earth transfer time on June 29 broke the shortest record since the invention of the atomic clock, the time of the earth rolling was much shorter. A study published in "Ancient Ocean Studies and Pianochia" in 2020 showed that 70 million years ago, when the dinosaurs were still wandering on the earth, the day on the earth was about 23.5 hours.

According to the NASA's record, the earth's rotation has slowed down since 1820. But in the past few years, the earth has begun to accelerate rotation.

Why is the earth rotation speed increased?

McCarthy, the retired director of the U.S. Navy Observatory, said that the researchers did not have a clear answer to why the earth rotates accelerated, but it is speculated that the land movement may be caused by changes in glaciers or the melting of glaciers.

McCarthy said that the glacier of the Earth's pole is pressed on the crust of the north and south poles, resulting in the distance between the north and south poles of the earth slightly lower than that of the equatorial diameter, which makes the earth a flat sphere. Due to the climatic crisis, the polar glacier is melting, and the pressure of the pole of the earth becomes smaller, which makes the crust move upward, the earth becomes round, and the circular shape helps the earth to rotate faster. Falter skating athletes use this phenomenon to improve and reduce rotation speed. When the skaters keep their arms away from the body when they rotate, the rotation requires greater power, and the speed becomes slower. When the arm is close to the body, the body is closer to the center of gravity, and the rotation speed will speed up. As the earth becomes more round, its quality becomes closer to the center, and the rotation speed becomes faster.

Do I need to remove a leap second?

Since researchers began to use the atomic clock to measure the rotation of the earth, the speed of the earth has been slowing down. "We don't even realize this milliseconds in daily life. But if these milliseconds are overwhelmed, we may change our use of leap seconds."

In order to solve the time caused by the reduction of the earth's rotation speed, the scientific community added leap seconds to the clock to slow down our time and match the time of the earth rotation. Since 1972, a total of 27 leap seconds have been added.

McCarthy said that because the earth rotates faster now, we need to remove the rotation speed of the leap second to catch up with the earth. However, even if the earth continues to maintain this trend, there will be no need to consider removing a leap second in the next three to four years.

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