Madrid 11 (European press)
It’s part of Isaac Newton’s law of universal gravitation, which he first formulated over 300 years ago. The constant cannot be derived mathematically; It must be determined by experience.
Over the centuries, scientists have conducted many experiments to determine the value of G, but the scientific community is not satisfied with the current figure. It is still less accurate than the values of all other fundamental natural constants, for example the speed of light in a vacuum.
One of the reasons why gravity is so difficult to measure is that it’s a very weak force that you can’t isolate: when you measure gravity between two objects, you’re also measuring the effect of every other object in the world.
“The only option to solve this situation is to measure the gravitational constant in as many different ways as possible,” explains Jörg Doal, professor in the Department of Mechanical and Process Engineering at ETH Zurich. He and his colleagues conducted a new experiment to redefine the gravitational constant and now present their work in the scientific journal Nature Physics.
To rule out sources of interference as much as possible, the Dual team set up their measuring equipment at what was known as Furggels Castle, located near Pfäfers above Bad Ragaz, Switzerland. The experimental setup consisted of two beams suspended in vacuum chambers. After the researchers vibrated the gravitational coupling, the second beam also showed slight motion (in the picometer range, i.e. one trillionth of a meter). Using lasers, the team measured the motion of the two beams, and measuring this dynamic effect allowed them to infer the magnitude of the gravitational constant.
A value higher than the current charge
The value the researchers arrived at using this method is 2.2 percent higher than the current official value provided by the Data Commission for Science and Technology.
However, Dual acknowledges that the new value is subject to significant uncertainties: “To get a reliable value, we still need to reduce this uncertainty by a significant amount. We are already in the process of making measurements with a slightly modified value.” Experimental setup so we can more accurately determine the G constant.” Preliminary results are available, but not yet published. However, Dual confirms: “We are on the right track,” he explains in a statement.
The researchers conducted the experiment remotely from Zurich, reducing disruption to site workers. The team can view real-time measurement data whenever they want.
For Dual, the advantage of the new method is that it measures gravity dynamically through moving beams. “In dynamic measurements, unlike static measurements, it does not matter that it is impossible to isolate the gravitational effect of other bodies,” he says. That’s why he hopes he and his team can use the experiment to help solve the mystery of gravity. Science has not yet fully understood this natural force or the experiences related to it.
