June 30: The first second in history is added and the endless race begins

Because the speed of the Earth's rotation is slowing down due to the gravitational influence of the Moon, we have to add a second to the atomic clocks to avoid time being deviated.

A profit of one second is added to UTC Coordinated Universal Time . Because the speed of the Earth's rotation is slowing down due to the gravitational influence of the Moon, we have to add a second to the atomic clocks to avoid time being deviated.

Historically, the first time a second added to UTC international time is on 23:59:59 on June 30, 1972. After that, leap seconds have been inserted around every 18 months. As of 2015, we've had 25 additions plus a second and the 26th time will take place on this night, June 30, 2015.

We are preparing to enter a special moment in history.

In the past, to measure the time we used pendulum clocks, mechanical watches or Sun clocks. By 1950, IERS's Orbital Control and Rotation Agency began using atomic clocks to measure time.

This type of watch gives an extremely high accuracy, a new 50 million years of deviation. However, this high accuracy also caused us to encounter some problems.

Atomic clocks have very high accuracy, 50 million new years deviate by 1 second.

We have two time scales, one is TAI Atomic Time and the other is UTC International Coordination time. While TAI is measured by an atomic clock, UTC is measured by the sun's growing and diving cycles, based on Earth's rotation.

The tide phenomenon, under the force of the Moon's gravitational force, causes the Earth to slow down due to the rotating kinetic energy being converted into another form of energy in lifting water on the Earth's surface. Over time, the sun's day becomes longer, resulting in a very small difference in the rotation of the Earth but it is enough to make a difference between TAI and UTC hours.

However, the slow speed of the Earth is not fixed and unpredictable. Therefore, the IERS organization will have to keep track of this slowdown rate and give time to add to the leap seconds, which will help the International clock and the Earth dial not be misleading. This is a very important responsibility, because if only one second is forgotten, it can cause very serious consequences.

The rotation speed of the Earth is slowing, which is why we have a leap second.

Also because the speed of the Earth's rotation is getting slower and slower, so the frequency of adding a leap second will increase over time. Scientists calculate that about 50,000 years after each day will last more than a second compared to today. That is, every day must add one second to the atomic clock. And that is an extremely complicated thing.

To keep up with these leaps of seconds, many big technology companies have had a headache to find solutions. Because adding a second to the system is not simple, the machines are not programmed to identify this additional second. It can cause many problems due to time out of synchronization.

Although it is only a second, the time difference can cause the user's commands and data to not be accepted by the computer. So many companies have proposed eliminating leap seconds. But if you completely eliminate the addition of one second, the result is even worse.

If eliminating leap seconds, will lead to the collapse of satellite systems and global interent networks.

According to calculations, if we do not change the time, until 2100 our clock will be 2-3 minutes faster than the real time of the Earth's rotation, and by 2700 will be 30 minutes. At that time, there will be no solution to adjust the atomic clocks to match the real time without affecting our computer system. As a result, satellites on Earth orbit will operate incorrectly, causing the global GPS system to collapse completely.