A modern example of the use of the concept of gravity is found in the practice of oil and gas exploration.
Oil and gas are less dense that rock, so a volume of oil or gas has less mass than the same volume of rock and therefore exerts less gravitational attraction than the volume of rock. Someone standing over rock is therefore slightly heavier than someone standing over an oil field. (The centrifugal force is the same but the gravitational pull downward is different.)
An instrument used to measure minute differences in the gravitational attraction of the Earth at different places on its surface is called a gravimeter. It consists of a mass m suspended from a spring. The mass is pulled more downward over rock than over oil. The difference is measured as a change in the extended state of the spring: