A trio of researchers working in France, along with a colleague from the U.K. has re-measured the gravitational constant using the same apparatus they built 12 years ago and have found a small change. In their paper published in Physical Review Letters, the team describes how they reconfigured their original equipment to re-measure the gravitational constant and this time came up with a slightly higher number than before.
The gravitational constant, denoted by G in math equations, has proven to be far more elusive than scientists imagined after it was first measured by Henry Cavendish approximately 200 years ago. The problem is that it’s far weaker than other forces such as electromagnetism. Fluctuating stronger forces acting on measurement equipment can cause changes to readings, leading to an inaccurate result. For that reason, scientists have been striving to come up with a way to definitively measure exactly how much force G exerts. In this new effort, the research team went back to the same apparatus they constructed 12 years ago—one that simultaneously measures G in two different ways. This time around, however, they reconfigured their device in ways they believed would make it more accurate—and in so doing found a slightly different result, but now, aren’t sure which of their measurements is actually more accurate. Via New measure of gravitational constant higher than expected.