This article explains how scientists have measured the strength of gravity over time, focusing on a key constant called G, which describes how strong the gravitational force is. Gravity is one of the fundamental forces in the universe, and understanding it helps predict the movement of planets, the behavior of galaxies, and even the formation of black holes. Despite its importance, G is not known with high precision, and different experiments have produced slightly different values, causing some confusion among scientists.
To measure G, scientists have used a device called a torsion balance, first developed by Henry Cavendish in the late 1700s. Modern versions of this device, like those used at NIST, involve carefully controlled masses and sensitive instruments to detect tiny gravitational effects. Newer methods also use quantum physics, such as atom interferometry, where ultracold atoms are used to detect differences in gravitational pull at very small distances. These techniques offer promising ways to improve the accuracy of G. While scientists are getting closer to agreement on G’s value, more precise measurements are still needed to fully understand gravity’s role in the universe.
Source: https://www.nist.gov/how-do-you-measure-it/the-cosmos/how-do-you-measure-strength-gravity
Keywords: gravitational constant, torsion balance, atom interferometry
