[Danning our country's heavy weapon 34] Absolute gravity instrument: accurately "CT" for the earth

Two iron balls of different sizes are left on the Pizza inclined tower. They landed at the same speed at the same speed -more than 400 years ago, Italian scientist Galileo completed the experience after the famous free falling experiment. Today's China Institute of Metrology Sciences The Yi Research Team can also experience it. However, unlike Galileo, the falling body they observed is not an iron ball, but an atomic ball.

Gravity instrument research team is one of the nine -meter foundation cutting -edge research team in the Chinese Metrology Institute. The team's work is to accurately measure gravity acceleration, establish a national gravity acceleration measurement base standard system, and develop independent and controllable precision measurement instruments- Absolute gravity instrument.

The measurement of gravity acceleration is divided into absolute gravity measurement and relative gravity measurement. The research of the Chinese Institute of Metrology has been studying the absolute gravity instrument for more than half a century. Since 2013, they have carried out a concentrated research on a new generation of laser interference absolute gravity instruments and the first -generation atomic interference absolute gravity instruments, breaking through more than ten "card necks" technology, greatly improving the measurement level of gravity acceleration. The synthetic standards of the measurement results of these two absolute gravity instruments have reached 3.0 and 4.6 microa, respectively.

Gal, that is, unit with gravity acceleration, is named to commemorate Galileo. Compared with Galileo at that time, the measurement uncertainty of the 3.0 and 4.6 micro -gab was equivalent to increasing the measurement accuracy of gravity acceleration by nearly 7 quantities, that is, the 7th side of 10, tens of millions of times.

This is the development of the times and the progress of science and technology. Galileo may not think that people can interfere with the absolute gravity instrument hundreds of years later, replace free falling objects from macro objects to micro -atoms, and use laser cooling and control technology in ultra -high vacuum environments to measure gravity acceleration.

More than that. The Chinese Institute of Metrology also uses independently developed laser interference and atomic interference absolute gravity instruments. By hosting international comparison and superconducting gravity observation technology, the national gravity acceleration measurement benchmark for different technical systems has been established. Over 1 microa.

In 2017, 32 gravity measuring instruments in 14 countries gathered in China to carry out "big competitions" -timeter comparison. The absolute gravity instrument of the Chinese Institute of Metrology is excellent, making the global gravity measurement benchmark settled in China. The so -called origin, the point with the highest measurement accuracy of global gravity acceleration, is also the source of global gravity acceleration value. Earlier, the original point of the global gravity measurement benchmark has been in Europe.

"This means that China has become the origin of the global gravity acceleration value, traceability and transmission of the amount of gravity acceleration for the world, which demonstrates my country's scientific and technological strength and international influence in the global measurement community." China Metrology Institute of Time Frequency Institute is deputy Wu Shuqing, the leader of the director and gravity research team, was proud.

Scientific researchers always pursue the ultimate, and the pursuit of higher accuracy is both a self -breakthrough and a real need. Such a high -precision gravity instrument is also useful in real life.

Affected by the gravity of the earth, there is almost the same gravity acceleration during the whereabouts of the object. However, under the influence of factors such as different latitude and strata, the gravity acceleration will change slightly. This change is an important basis for assisted navigation, resource exploration, earthquake forecasting, and marine monitoring.

For example, the use of gravity signals in different positions and standard gravity maps can obtain positioning and navigation methods. According to the abnormal or mutations of the gravity field, you can explorate the resources and determine what kind of resources. Researchers have proved the shape, location and depth of the underground tomb of the thirteen tombs of Beijing through gravity measurement. The accuracy we use in our lives is also based on accurate gravity measurement ...

As a country's basic data and strategic data, the precise measurement of gravity acceleration has never stopped.In recent years, in major national engineering projects such as "Mainland China Scientific Drilling Project", "Mainland China Construction Environmental Monitoring Network", "Polar Science Research", "Precision Gravity Measurement State Construction of National Science and Technology Infrastructure", you can see the absolute gravity instrumentFigure."They are" doing CT 'more accurately to the earth, let us know more about human homes. "The China Institute of Metrochemical Gravity Instrument described so much."Guangming Daily" (01, August 06, 2022)

Supervision: Zhang Ning Liao Hui

Plan: Li Fangzhou Li Yimeng

Dubbing: Zhang Yuexin

Copywriter: Dong Dazheng

Editing: Bai Bing

Production: Guangming News Center

Interview: Chen Haibo, a reporter from Guangming Daily

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