Instrumental capabilities for both relative and absolute gravity measurements have evolved over the past 40 years to the point where today measurements can be made at the parts in 109 level of precision. Large but still portable absolute gravimeters have also reached the parts in 109 level of accuracy. Present emphasis is on the developemnt of smaller absolute gravimeters that would greatly facilitate the use of gravity in field applications. One approach to a small, field-usable, absolute instrument would involve measuring g by dropping atoms. This development - when it happens - would use not just new physics but would also have associated with it a (somewhat) different set of measurement-limiting errors. In this paper, I will discuss some of the reasons for the remarkable progress in our ability to measure absolute gravity, and I will also discuss the future prospects for old gravity continuing to assist us in new learning about the earth on which we live.
absolute gravimeters, gravity measurements
Instrumentation for Old Gravity, Luxembourg Symposium
(Accessed February 21, 2024)