Physicists Have Calculated The Most Precise Value Of Gravitational Constant Till Now


A part of a branch of Physics called Quantum physics deals with clarifying or providing a framework to understand the already existing theories. The Gravitational constant or universal gravitational constant, which is denoted by the letter G is an example of the challenges which were faced by physicists. A team of scientists in China has produced the closest results so far with their latest study. The value is determined by measuring the distance and mass of two objects which were relative to their gravitational attraction. The challenge becomes much more difficult when other forces like electromagnetism, weak interaction, and strong interaction are compared to the gravitational force which is weaker as compared to these forces.

The team used an angular acceleration feedback method and time of swing method to achieve the closest results. For many years, the preexisting value was 6.673889 x 10^-11 m^3 kg^-1 s^-2. The results which the Chinese physicists achieved were 6.674184 x 10^-11 m^3 kg^-1 s^-2 and 6.674484 x 10^-11 m^3 kg^-1 s^-2. This implies that the team was able to produce their results with a relatively small standard deviation number. The team also made the point clear that their result illustrates “undiscovered systematic errors in the various existing methods.” The most preferred method involved interferometry which is a method that interferes with atomic waves while scientists are making efforts to improve the overall process.

Before the recent findings were disclosed, this method had produced the smallest relative uncertainty, which means it had been the foundation of most of the research contributions in this area. Stephan Schlamminger, an expert at the National Institute of Standards and Technology (NIST), talked about the study and said, “Li et al. carried out their experiments with great care and gave a detailed description of their work. The study is an example of excellent craftsmanship in precision measurements. However, the true value of G remains unclear. Various determinations of G that have been made over the past 40 years have a wide spread of values. Although some of the individual relative uncertainties are of the order of 10 parts per million, the difference between the smallest and largest values is about 500 parts per million.”

Within physics, there are many empirical and unchanging laws which deal with the universe. It depends on the members of the scientific community to find fresh approaches to see them. The work produced by this team is serving as an excellent example to find the new methods. The details about the recent study appeared in a paper called, “Gravity measured with record precision.”