The discussion revolves around the stability of the gravitational constant and the potential for measuring changes in gravity over time. Participants assert that for gravity to change significantly, there would need to be a corresponding change in Earth's mass, which lacks evidence outside of theories like moon formation. Current observations consistently support the gravitational constant's stability. The conversation also touches on the possibility of measuring gravity in the past through observations of distant space objects, such as binary stars or pulsars, and whether these observations can validate current gravitational theories. However, there is a noted lack of information on historical measurements of the gravitational constant based on space objects. The discussion emphasizes the application of existing theories to observed phenomena to support or challenge current understanding of gravity.