The Center for Gravitational Experiments (CGE), engaged in the research on gravitational experiments, precision gravity measurements and related theories since 1983. It is now the only research center in China involved in gravitational experiments, and also a well-known research center especially for the precision measurement of the Newtonian gravitational constant. The currently-in-use CGE laboratory covers about 6,800 square meters, including a 4,000-m2 cave laboratory. The cave laboratory is an ideal environment for all precision experiments: the daily temperature variation is less than 5 mK, the annual temperature variation is less than 1K, the seismic noise is 100 times smaller than that in a typical basement laboratory; moreover, the electromagnetic interference is shielded almost completely inside the cave laboratory.
In recent years, the CGE has continued to strengthen its experimental equipments and basic infrastructure; part of the cave laboratory has been rebuilt into a modern clean-room laboratory. The total research funding approved in the past ten years was more than “80 million RMB”.
Numerous novel precision measurement techniques have been developed, e.g. ultra-weak force detection and calibration based on the torsion pendulum technique, capacitive displacement sensing, fiber-optic displacement sensing, precision measurement of gravitational acceleration based on atom interferometry, precision spectroscopy, ultrastable lasers, cryogenic scanning probe microscopy, precision heterodyne laser interferometry, etc.
- Chief Scientist
Professor Jun Luo,
Currently the vice president of HUST, is also academician of the Chinese Academy of Science. He engages in gravitational experiments since 1983. His major achievements in science include:
- Using the time-of-swing method to measure the precision value of the Newtonian gravitational constant, and the measured value had been recorded by CODATA;
- Using macroscopic rotating objects to test the Equivalence Principle of General Relativity;
- Using the modulated torsion balance to determine the upper limit of the photon rest mass, and the result had been recorded by the Particle Data Group;
- Using the precision torsion pendulum with dual-frequency modulation to test the Newtonian inverse-square law at the sub-millimeter range.
Prof. Hou-Ze Xu,
Academician of the Chinese Academy of Science, was also the former Dean of the Wuhan Branch, Chinese Academy of Sciences. He engages in geodesy and geophysics since 1962, and is currently being:
- Executive Committee of the International Association of Geodesy,
- Chairman of the International Committee of the Earth Tide,
- Vice Chairman of the Chinese Society of Surveying and Mapping.