Reveal the "Time Magic Box" atomic clock

What is time? Maybe someone would look down at the watch and speak at the moment. Yes, the clock will tell us time that it is an indispensable part of our lives. After determining the starting point, the time value is used to record the time value of the century, year, month, day, time, minute, and second, as if a ruler.

When human beings realize the passage of time, they begin to use cyclical phenomena to track time. In ancient times, humans judged the season through the glory of grass and trees, and judged time by observing the movement of the sun and the moon in the sky. Later, people explored the water clocks that dripped the time, and the bellglass of the flowing sand time. After World War II, the National Physics Laboratory developed the world's first atomic clock, but this clock needs a room equipment, which is too high and highly practical, but represents a historic leap. In 1967, the definition of the second long trace on the atom. Since then, various atomic clocks have come out one after another, and have become the most accurate time tools in the world, and their practicality has become higher and higher, which can meet the application needs of various scenarios.

The atomic clock is actually very close to people's daily life. For example, the atomic clock plays a "heart" role in the satellite navigation system. Satellite navigation makes people's daily life very convenient. When we take out the mobile phone to open the navigation software, we can see our geographical location, enter the destination, navigation software can plan the route, and tell us in real time telling us that we need to turn left or right to the right. change. How does this do?

The principle of satellite navigation and positioning

In the three -dimensional space, the coordinate system is established. When the coordinates of the three points and the distance between the fourth unknown point and the known points, the unknown points can be determined. In the same way, when we look up at the sky on the earth, we can at least see at least 3 satellites and satellites flying on our own track. To solve, you can know the position of the satellite. In addition, we need to know the distance between us and satellites. Physics knowledge tells us that the distance is equal to the speed multiplied by time, and the speed of light transmission is 300,000 kilometers per second, so we only need to know the signal transmission time. At this time, we found that the key to navigation positioning is the measurement of time.

This requires a grand debut. Each satellite and ground station are equipped with a group of atomic clocks. The time signal is sent with the star calendar. In the process of solving the position of the satellite, time information and distance can be obtained at the same time. In this way, our position can be calculated.

Electronic products such as mobile phones in daily life usually have built -in navigation modules, which can receive signals emitted by satellite in real time and be solved according to certain algorithms. As a result, we have real -time control of our own position. If the time error provided by the atomic clock is at 1 microsecond, the positioning error will be as high as 300 meters. If you want to reach a meter of navigation, without considering other error factors, the time error provided by the atomic clock must be kept at 3 nan seconds. In other words, the precision measurement of time determines the accuracy of navigation positioning. If there is no atomic clock, accurate navigation cannot be achieved.

How accurate is the atomic clock?

Let's compare with common robot watches and quartz clocks. When we drove the car with a robotic watch, run around the four ring around Beijing for 1 hour, about 1 hour, the mechanical watch is biased for 1 second; for the quartz clock, it takes about 270 years to bond for 1 second, that is, that is, that is, that is, that is, that is, that is, that is, that is, If we return to the Qing Dynasty with a quartz clock and give her when we encounter Xia Yuhe in the south of Qianlong, then, today in 2022, this watch has only 1 second; how long does the atomic clock deviation take for 1 second, 30 million years! If we give the last tyrannosaurus on the earth, then this atomic clock will only be biased for 2 seconds to this day.

Looking at the more than 100 elements on the cycle table, there are only more than 10 species suitable for the development of atomic clocks, and these atoms have different temper and nature, and they need to be treated carefully. Therefore, after catching the atoms, scientists must also ensure that they are not disturbed by external magnetic fields, electric fields, and temperature changes. The complexity of a atomic clock may exceed people's imagination. Dozens of screws may be used, hundreds of electronic components, and after thousands of test verifications, the efforts of countless scientific researchers are condensed.

There is unknown secrets hidden in the vast universe

We are eager to know

What does the black hole look like

We are eager to see the traces of gravitational waves

We are also eager to talk to biological biology outside the earth

These yearning for unknown

Make humans never stop

The pursuit of time frequency measurement accuracy

Records of the accuracy of the atomic clock are still being refreshed

The atomic clock serving life in one station

It is the result of unremitting efforts of aerospace workers

Is the motivation to continue to move forward

It is also a reflection of aerospace spirit

Source: Chinese Aerospace

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