Big G is the oldest fundamental constant in physics and remains the least clearly defined. One scientist has spent a decade attempting to crack the mystery of the gravitational constant, and it all came down to the opening of a single envelope.

'One of the great unresolved embarrassments of physics': It's been 340 years since Newton and scientists still haven't solved the secret of gravity

Source: space
Source Link: https://www.space.com/science/one-of-the-great-unresolved-embarrassments-of-physics-its-been-340-years-since-newton-and-scientists-still-havent-solved-the-secret-of-gravity