A rotating gauge method is used to measure the span between two spheres with high precision in determination of the gravitational constant G.A rectangular gauge block slightly shorter than the span is located horizont...A rotating gauge method is used to measure the span between two spheres with high precision in determination of the gravitational constant G.A rectangular gauge block slightly shorter than the span is located horizontally between two spheres,and the angle between two symmetric bounding points during rotation can be determined by measuring the shift of a laser beam passing through an optical plate fixed on the gauge block.Experimental results show that the uncertainty in the determination of the span between the two spheres is less than 0.5μm.展开更多
The thermoelastic effect of the suspension fibre in the torsion pendulum experiment with magnetic damping was studied.The disagreement in the oscillation periods was reduced by one order of magnitude through monitorin...The thermoelastic effect of the suspension fibre in the torsion pendulum experiment with magnetic damping was studied.The disagreement in the oscillation periods was reduced by one order of magnitude through monitoring the ambient temperature and thermoelastic correction.We also found that the period on uncertainty due to noise increases with the amplitude attenuation after thermoelastic correction.展开更多
We propose a novel scheme for testing the equivalence principle with rotating cold polar molecules whose angular momenta are polarized at different states.Molecules in specific rotational states are selected out via t...We propose a novel scheme for testing the equivalence principle with rotating cold polar molecules whose angular momenta are polarized at different states.Molecules in specific rotational states are selected out via the hexapole state-selection technique and the gravitational acceleration g of molecules is measured by measuring the Doppler shift of the molecules free falling in the gravitational field.Some other possible methods of rotating molecules and measuring g are also mentioned.Molecules,as the test masses,have higher rotating speed and smaller dimension in comparison with mechanical gyroscopes and may open a new way for testing the equivalence principle and the possible coupling between rotation and gravity.展开更多
A symmetric disc-shaped torsion pendulum was designed to study the nonlinear effects of the torsion fiber. It was showed that the period of the pendulum decreases with the amplitude of the oscillation. Determination o...A symmetric disc-shaped torsion pendulum was designed to study the nonlinear effects of the torsion fiber. It was showed that the period of the pendulum decreases with the amplitude of the oscillation. Determination of the unperturbed period through a fit to measured data of the period variation with amplitude shows that this systematic error in the measurement of Newtonian gravitational constant G by the time-of-swing method can be reduced by an order of the magnitude at least.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.19835040.
文摘A rotating gauge method is used to measure the span between two spheres with high precision in determination of the gravitational constant G.A rectangular gauge block slightly shorter than the span is located horizontally between two spheres,and the angle between two symmetric bounding points during rotation can be determined by measuring the shift of a laser beam passing through an optical plate fixed on the gauge block.Experimental results show that the uncertainty in the determination of the span between the two spheres is less than 0.5μm.
基金Supported by the National Natural Science Foundation of China under Grant No.19835040.
文摘The thermoelastic effect of the suspension fibre in the torsion pendulum experiment with magnetic damping was studied.The disagreement in the oscillation periods was reduced by one order of magnitude through monitoring the ambient temperature and thermoelastic correction.We also found that the period on uncertainty due to noise increases with the amplitude attenuation after thermoelastic correction.
基金Supported by the National Basic Research Program of China under Grant No 2010CB832806the National Natural Science Foundation of China under Grant No 41127002.
文摘We propose a novel scheme for testing the equivalence principle with rotating cold polar molecules whose angular momenta are polarized at different states.Molecules in specific rotational states are selected out via the hexapole state-selection technique and the gravitational acceleration g of molecules is measured by measuring the Doppler shift of the molecules free falling in the gravitational field.Some other possible methods of rotating molecules and measuring g are also mentioned.Molecules,as the test masses,have higher rotating speed and smaller dimension in comparison with mechanical gyroscopes and may open a new way for testing the equivalence principle and the possible coupling between rotation and gravity.
基金the National Natural Science Foundation of China under Grant Nos.19425008 and 19835040.
文摘A symmetric disc-shaped torsion pendulum was designed to study the nonlinear effects of the torsion fiber. It was showed that the period of the pendulum decreases with the amplitude of the oscillation. Determination of the unperturbed period through a fit to measured data of the period variation with amplitude shows that this systematic error in the measurement of Newtonian gravitational constant G by the time-of-swing method can be reduced by an order of the magnitude at least.